Decision Regret About Treatment Amongst Women With Early Breast Cancer: An Integrative Review

ABSTRACT

Aims

To synthesise evidence on decision regret about treatment amongst women with early breast cancer, including (1) the type of treatment related to decision regret, (2) the level of decision regret, and (3) factors associated with decision regret.

Design

Integrative review.

Methods

Studies published between January 2000 and December 2023 were searched from five online databases to provide up‐to‐date evidence. The Joanna Briggs Institute critical appraisal tools were used to evaluate the quality of the studies. The constant comparison strategy was employed for data analysis.

Results

A total of 26 studies were included. Breast cancer surgery was the most frequently studied treatment in relation to decision regret amongst women with early breast cancer, while adjuvant therapies were less studied. Most studies reported low levels of decision regret, while several studies found high levels. The proportion of women reporting decision regret varied considerably from 2.5% to 69% across the included studies. Factors associated with decision regret included various socio‐demographic and clinical characteristics (age, ethnicity, employment, education, health literacy, cancer stage, and treatment types), decision‐making experiences (patient involvement, patient preference, accessing information, and the use of decision support tools), and mental health.

Conclusion

Decision regret occurs in women with early breast cancer after surgery and adjuvant therapies. A variety of factors should be considered during the treatment decision‐making process to minimise decision regret. More robust studies are needed to disaggregate decision regret by treatment type and to evaluate the effectiveness of decision support tools in reducing decision regret in women with early breast cancer.

Impact

Nurses and other healthcare professionals should be aware of the potential for decision regret related to surgery and adjuvant therapies in women with early breast cancer. The findings can help nurses and other healthcare professionals identify women at higher risk of experiencing decision regret and provide support during the treatment decision‐making process to mitigate it.

Reporting Method

PRISMA 2020 Statement.

Patient or Public Contribution

No patient or public contribution to this review.

1. Introduction

Breast cancer is the most prevalent cancer amongst females in 157 out of 185 countries (Arnold et al. 2022; Bray et al. 2024). Its incidence has increased rapidly and affected more than 2 million women in 2022 worldwide (Arnold et al. 2022; Bray et al. 2024). Due to early detection improvements, most breast cancer cases are identified in the early stages (Centers for Disease Control and Prevention 2024; National Cancer Control Indicators 2018). This study focused on early breast cancer in females. We define breast cancer according to the National Cancer Institute, referring to cancers that have not spread beyond the breast or the axillary lymph nodes, including ductal carcinoma in situ (DCIS; stage 0), stage I, stage II, and stage IIIa breast cancers (National Cancer Institute Dictionary of Cancer Terms 2024).

Early breast cancer typically presents with milder symptoms (e.g., a smaller lump and no involvement of lymph nodes) and is associated with prolonged survival compared to advanced stages. This leads to multiple treatment options for women diagnosed with early breast cancer (Benson et al. 2009; Gradishar et al. 2022). Primary surgical options include breast‐conserving surgery (BCS) and mastectomy. Other treatment options may consist of combinations of these surgical approaches with adjuvant therapies, including chemotherapy, radiotherapy, hormone therapy, or targeted therapy (Benson et al. 2009; Gradishar et al. 2022). Some treatment approaches have been shown to provide comparable survival outcomes for early breast cancer, such as mastectomy versus BCS with radiotherapy (Clarke et al. 2005; Gradishar et al. 2022; Veronesi et al. 2002). Hence, when women are diagnosed with early breast cancer, they are often required to consider different treatment strategies and make a treatment decision (Liu et al. 2021). This complexity can lead to decision regret about treatment.

Decision regret is defined as a negative emotion involving “remorse or distress over a decision” (Brehaut et al. 2003). It occurs when people feel their circumstances would have been more favourable if they had made a different decision (Gilovich and Medvec 1995; Martinez et al. 2015). Decision regret often involves self‐recrimination, which imposes a hefty psychological burden on patients (Connolly and Zeelenberg 2002; Groopman and Hartzband 2017). Decision regret related to treatment has also been shown to be associated with other poor health outcomes, such as decreased satisfaction with treatment decision‐making (Skyring, Mansfield, and Mullan 2021), higher self‐stigma (Zhuang et al. 2022), poor patient well‐being (Xu, Zhou, and Wang 2021), as well as impaired quality of life (Zhuang et al. 2022). Decision regret has also been linked to dissatisfaction with the provider team (Fortunato et al. 2021) and difficulties in the provider–patient relationship (Chichua et al. 2022).

Previous studies have demonstrated that many women with early breast cancer experience decision regret regarding their treatment. For example, Yamauchi, Nakao, and Nakashima (2019) found that 51.4% of 467 Japanese women with early breast cancer reported experiencing some regret about their treatment decisions (Yamauchi, Nakao, and Nakashima 2019). Hawley et al. (2008) found that amongst 877 American women with early breast cancer, nearly 39% reported a high amount of decision regret about their surgical treatment, while 30% reported a moderate amount of decision regret (Hawley et al. 2008). Literature reviews have been conducted on decision regret regarding treatment in breast cancer settings, such as breast reconstruction (Flitcroft, Brennan, and Spillane 2018) and risk‐reducing mastectomy (a mastectomy performed to reduce the risk of developing breast cancer) (Braude et al. 2017). However, since most women with early breast cancer do not undergo reconstruction or risk‐reducing mastectomy, a review synthesising decision regret about primary treatment in early breast cancer is needed (Liu et al. 2022). Thus, an integrative review was conducted to provide a comprehensive understanding of decision regret related to treatment in early breast cancer. This knowledge could support improvements in women's treatment decision‐making, mitigate decision regret, and enhance health outcomes. The protocol related to this review has been previously published (Liu et al. 2022).

2. The Review

An integrative review was conducted. This method synthesises findings from various types of evidence to develop a thorough understanding of complex phenomena (Whittemore and Knafl 2005). It is well‐suited for the current review, which aims to provide a comprehensive understanding of decision regret related to treatment in early breast cancer. Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) was followed to ensure the reporting quality of this review (Page et al. 2021).

3. Study Design

This review followed a five‐stage integrative review approach, which included problem identification, literature search, data evaluation, data analysis, and presentation (Whittemore and Knafl 2005).

3.1. Problem Identification Stage

This review was conducted to synthesise evidence on decision regret regarding treatment in women with early breast cancer, including (1) the type of treatment related to decision regret, (2) the level of decision regret, and (3) factors associated with decision regret.

3.2. Literature Search Stage

3.2.1. Inclusion and Exclusion Criteria

The included studies must meet the following criteria: (1) they must be empirical studies, (2) they must report on decision regret, (3) they must focus on decision regret in women with early breast cancer (stages 0, I, II, and IIIa) (National Cancer Institute Dictionary of Cancer Terms 2024), and (4) they must be published in the English. Studies involving more advanced stages (e.g., stage IIIb and stage IV) were also included if they provided separate analyses and reported on decision regret in women with early breast cancer.

Studies were excluded if they solely reported decision regret related to breast reconstruction and risk‐reducing mastectomy, as reviews on these topics have already been conducted (Braude et al. 2017; Flitcroft, Brennan, and Spillane 2018). Secondary literature (e.g., reviews) and grey literature (e.g., government reports) were excluded. Studies published in languages other than English were also excluded.

3.2.2. Information Sources

CINAHL Complete, Embase, PubMed, Medline, and the Web of Science were searched. To obtain up‐to‐date evidence, studies published from January 2000 to December 2023 were searched. The reference lists of eligible studies were also manually searched. The literature search was conducted in December 2023.

3.2.3. Search Strategy

The search terms covered all terms related to this review's subjects: “early breast cancer,” “regret,” and “treatment.” The full search strategies for each online database are provided in Supporting Information.

3.2.4. Selection Process

Studies identified from each online database were imported into EndNote software for further selection. Duplicate studies were initially identified and removed using the built‐in features of EndNote. After de‐duplication, two authors independently screened the titles and abstracts of the studies against the inclusion criteria. These authors then retrieved the full articles, reviewed them carefully, and assessed their eligibility based on the inclusion and exclusion criteria. The selection process was thoroughly discussed amongst all authors in regular research meetings, and disagreements were resolved through discussion.

3.2.5. Search Outcomes

A total of 5921 studies were identified from the online databases. After removing duplicates (n = 366) using EndNote's built‐in function and excluding records by publication types (n = 593) and languages (n = 168), the remaining 4794 studies underwent screening based on titles and abstracts. A total of 4248 studies were further excluded due to being unrelated to breast cancer (n = 1331) and unrelated to decision outcomes (n = 2917). A manual check was conducted to exclude duplicates not identified by EndNote (n = 50). Full texts for the remaining 496 studies were retrieved and assessed for eligibility. Of these, 470 studies were excluded based on the eligibility criteria, resulting in 26 studies for the final review. The reference lists of these 26 studies were manually searched, resulting in 3 additional studies. However, none of them met the inclusion criteria and were therefore excluded. Hence, a total of 26 studies were included in the final review. The selection process is detailed in a PRISMA flow diagram, as presented in Figure 1.

FIGURE 1.

Flow diagram for the study selection.

3.3. Data Evaluation Stage

Two authors independently evaluated the methodological quality of the studies using the Joanna Briggs Institute critical appraisal tools. These tools were developed to assess the trustworthiness, relevance, and outcomes of studies with various designs and are widely used for assessing study quality in reviews. After resolving minor disagreements on the response to each checklist by discussing it within the author team, all authors agreed that all 26 studies should be included. The methodological quality of the included studies is presented in Table 1.

TABLE 1.

The methodological quality of the included studies (n = 26).

No.	First author, year	Design	Checklist items													Appraisal outcomes
			1	2	3	4	5	6	7	8	9	10	11	12	13
1	Goel 2001	RCT	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Included
2	McVea 2001	Qualitative	No	Yes	Yes	Yes	Yes	No	Yes	Yes	No	Yes	—	—	—	Included
3	Killoran 2006	Qualitative	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	Included
4	Boehmer 2007	Qualitative	Yes	Yes	Yes	Yes	Yes	No	No	Yes	Yes	Yes	—	—	—	Included
5	Hawley 2008	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
6	Noh 2008	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
7	Lally 2009	Qualitative	Yes	Yes	Yes	Yes	Yes	No	No	Yes	Yes	Yes	—	—	—	Included
8	Step 2009	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
9	Fernandes‐Taylor 2011	Qualitative phase	No	Yes	Yes	Yes	Yes	No	No	Yes	Yes	Yes	—	—	—	Included
		Cross‐sectional phase	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	—	—	—	—	—
10	Lam 2013	RCT	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Included
11	Livaudais 2013	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
12	Lam 2014	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
13	López 2014	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
14	Lee 2015	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
15	Martinez 2015	Longitudinal	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
16	Sepucha 2015	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
17	Burton 2017	Cross‐sectional	Yes	Yes	Yes	Yes	No	No	No	Yes	—	—	—	—	—	Included
18	Kwok 2017	Qualitative	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	Included
19	Swanick 2018	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
20	Wang 2018	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
21	Lee 2019	Cross‐sectional	Yes	Yes	Yes	Yes	No	No	Yes	Yes	—	—	—	—	—	Included
22	Yamauchi 2019	Cross‐sectional	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	—	—	—	Included
23	Zdenkowski 2019	Longitudinal	Yes	Yes	Yes	Yes	No	No	Yes	Yes	—	—	—	—	—	Included
24	Schulman‐Green 2020	Qualitative	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	—	—	—	Included
25	Durand 2021	RCT	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Included
26	Sondergaard 2021	Cohort	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	—	—	Included

Note: RCT, randomised controlled trial.

3.4. Data Analysis and Presentation Stages

Data analysis was conducted following the constant comparison strategy proposed by Whittemore and Knafl (Whittemore and Knafl 2005), which includes data reduction, data display, data comparison, and conclusion drawing and verification. A self‐developed review matrix was used to facilitate data analysis. Studies were initially classified based on the types of evidence. Data regarding authors, year of publication, country, setting, study aims, study design, sample, and measurements of decision regret (the number of participants reporting their perspectives on decision regret, the tools to measure decision regret, and the timing of measurement) were extracted. The specific type of treatment related to decision regret, the level of decision regret, and factors associated with decision regret were also identified and coded. For studies involving more advanced stages, only data related to early breast cancer were extracted.

The extracted data were organised into the review matrix, and conclusions were drawn by counting, comparing, and contrasting the data to identify similarities and differences across the reviewed studies. After reading the articles, the first author extracted and organised data into the review matrix. Results and conclusions were intensively discussed and verified by all authors during our regular research meetings. The review results are presented in two tables.

4. Findings

4.1. Characteristics of the Studies

A total of 26 studies were included in this review, including 19 quantitative studies, 6 qualitative studies, and one study using a multi‐methods design. Most studies (n = 15) were conducted in the United States. Most studies (n = 23) focused exclusively on early breast cancer, while 3 studies also included women with more advanced stages (e.g., stage IIIb and stage IV) but reported decision regret separately for those with early stages (Fernandes‐Taylor and Bloom 2011; Martinez et al. 2015; Noh et al. 2008). The number of participants reporting their perspectives on decision regret varied widely across the included studies, with quantitative studies involving 51 to 2085 participants and qualitative studies involving 7 to 34 participants.

Amongst 19 quantitative studies, 13 used cross‐sectional designs to evaluate decision regret at a single time point after treatment. Three randomised controlled trials (RCTs) and one prospective cohort study assessed the effectiveness of decision support tools on decision regret. Two single‐arm longitudinal studies examined decision regret over different time points. For example, Martinez et al. (2015) investigated whether women's reported decision regret after breast cancer treatment changed over time. This study measured decision regret at two time points: 9 months after diagnosis and again 4 years later (Martinez et al. 2015). The majority of the quantitative studies (13 out of 19) employed the decision regret scale (DRS) as the tool to assess decision regret (Brehaut et al. 2003); however, the reporting of DRS results varied, with some studies providing the overall mean score for the entire scale, while others presenting the percentage distribution of responses for each item of DRS. The remaining studies (n = 6) used the study‐specific single‐item question, most of which used categorical answers, for example, “no decision regret” versus “have decision regret” (Livaudais et al. 2013). This review thus considered the level of decision regret from two perspectives: the mean score of the DRS and the proportion of women who reported experiencing decision regret. This stratification enabled the synthesis of findings from different reports on the level of decision regret.

Six studies were qualitative, with 4 conducting individual semi‐structured interviews, one conducting focus group interviews, and another using multiple qualitative approaches including focus group discussions, individual semi‐structured interviews, and ethnographic observations (Boehmer, Linde, and Freund 2007; Killoran and Moyer 2006; Kwok and Koo 2017; Lally 2009; McVea, Minier, and Johnson Palensky 2001; Schulman‐Green et al. 2020). These qualitative studies examined women's decision‐making regarding breast cancer treatment, with regret emerging as an important finding in their experiences.

Another study used a multi‐methods design, where an individual semi‐structured interview was conducted to identify the content of decision regret and a quantitative analysis to identify the factors associated with decision regret (Fernandes‐Taylor and Bloom 2011). The characteristics of the included studies are presented in Table 2.

TABLE 2.

The characteristics of the included studies (n = 26).

No.	First author, year	Country and setting	Study aims	Study design	Sample	Measurement of decision regret
						Numbers of participants a	Tools	Timing of measurement
1	Goel 2001	Canada Community hospitals in Toronto, Ontario	To assess a decision aid for women with breast cancer. Decision regret is one of the outcomes	RCT	Women with stage I–II breast cancer and suitable for either mastectomy or BCS	In total: 107 Decision aid arm: 63 Control arm: 44	DRS This study reported the numbers and percentages of participants who responded with “strongly agree” or “agree” to each item of DRS	6 months after surgery
2	McVea 2001	USA Nebraska	To explore how low‐income women make breast cancer treatment decisions	Individual interview	Low‐income women with stage I or II breast cancer	25	Interview questions	Mean time: 1.8 years after diagnosis
3	Killoran 2006	USA Hospitals and public health centers in northern California	To explore the cultural factors that influence treatment selections in Chinese‐American women	Focus group discussions, individual interviews, and ethnographic observations	Chinese‐American women with stage I or II breast cancer	Focus group discussion: 34 Individual interviews: 28 Ethnographic observations: 4	Interview questions	Mean time for focus groups: 38 months since diagnosis Mean time for individual interviews: 31 months
4	Boehmer 2007	USA Study settings were not reported	To explore which issues sexual minority women considered when making breast cancer treatment decisions	Individual interview	Sexual minority women with stage 0–II breast cancer	7 (who had a mastectomy without reconstruction)	Interview questions	Mean time: 31.9 months after diagnosis
5	Hawley 2008	USA Los Angeles Surveillance, Epidemiology, and End Results cancer registry	To compare the treatment decision‐making of Latina breast cancer patients with that of other ethnic groups. Decision regret is one of the outcomes	Cross‐sectional design using questionnaires	Latina, African American, and Caucasian women with stage 0–IIIa breast cancer	877	DRS DRS was categorised into three levels based on tertiles	Mean time: 9 months after surgery
6	Noh 2008	South Korea 5 hospital‐based breast cancer registries	To assess the associations between clinical experiences and patient outcomes. Decision regret is one of the outcomes	Cross‐sectional design using questionnaires	Korean women with stage 0–III breast cancer. Only results related to stage ≤ IIa breast cancer were included in the analysis for the current review	A total of 2085 women with stage 0–III breast cancer reported their decision regret, but the number of women with stage ≤ IIa was not provided	Study‐specific single‐item question: “Would you choose the same type of surgery again if you had the chance?”	Median time: 50 months after surgery
7	Lally 2009	USA A multispecialty breast center in the Midwestern region	To explore pre‐treatment thoughts regarding their surgical treatment decision‐making experience	Individual interview	Women with stage 0–II breast cancer	18	Interview questions	Mean time: 12 days after diagnosis but before treatment
8	Step 2009	USA 14 oncology practices in 2 states	To assess the relationships between patient demographics, oncologist relational communication, patient communication involvement, and decision regret	Cross‐sectional design using an audio‐recording observational approach and questionnaires	Women with early breast cancer	179	DRS Mean scores on a scale of 1–5	3 months post‐visit
9	Fernandes‐Taylor 2011	USA A cancer registry in the San Francisco Bay Area	To explore what young women regret 5 years later and which treatment‐related factors predict regret	A qualitative interview was used to identify content of regret, and a cross‐sectional quantitative analysis to identify predictive factors.	Young women with stage 0, local, and remote or regional breast cancer. Only results about stage 0 and local breast cancer were included in the current review	In total: 449 Stage 0: 17.9% Local stage: 49.7%	Open questions “Looking back, is there anything about your treatment that you would do differently?”	5 years after treatment
10	Lam 2013	Hong Kong, China Two government‐funded breast centers	To assess the effectiveness of a decision aid for breast cancer patients. Decision regret is one of the outcomes	RCT	Chinese women with early breast cancer	In total: 225 Decision aids group: 113 Control group: 112	DRS Mean scores in a scale of 0–100	1, 4, and 10 months after surgery
11	Livaudais 2013	USA 8 hospitals in New York City	To assess the association between patient‐perceived responsibility in decision‐making, treatment knowledge, and decision regret at 6‐month follow‐up	Cross‐sectional design using questionnaires	Women with stage I–II breast cancer who were candidates for adjuvant therapy	327	Study‐specific single‐item question “If I had to do it over, I would make a different decision about breast cancer treatment”	6 months after baseline
12	Lam 2014	Hong Kong, China Two government‐funded breast centers	To assess shared decision‐making and whether shared decision‐making improves decision outcomes. Decision regret is one of the outcomes	Cross‐sectional design using questionnaires	Chinese women with early breast cancer	283	DRS Mean scores on a scale of 0–100	1 month after surgery
13	López 2014	USA 8 Cancer Registry regions in California	To compare treatment participation, satisfaction, and regret in Latina and White women with DCIS	Cross‐sectional design using questionnaires	Latina and White women with DCIS	742	Study‐specific single‐item question “If I had to do it over again, I would make a different decision”	Mean time: 23.8 months after diagnosis
14	Lee 2015	USA The greater New York City area	To assess breast cancer treatment decision outcomes and examine associated factors in Chinese‐ American women Decision regret is one of the outcomes	Cross‐sectional design using questionnaires	Chinese‐American women with stage 0, I, II, or IIIa breast cancer	122	DRS Mean scores in a scale of 0–100	3–12 months after surgery
15	Martinez 2015	USA Los Angeles County or Metropolitan Detroit Surveillance, Epidemiology, and End Results tumour registries	To assess changes in post‐treatment decision regret over time	Longitudinal design, single‐arm	Women with stage 0–III breast cancer. This study separately reported on decision regret in the early stages (0–II)	1536	DRS Mean scores in a scale of 0–20	Two time points: 9 months and 4 years after diagnosis
16	Sepucha 2015	USA The cancer registry from Orange or San Diego Counties in California	To assess the quality of surgical decisions and the associated factors in Latina women with breast cancer. Decision regret is one of the outcomes	Cross‐sectional design using questionnaires	Latina women with stage I or II breast cancer	97	Study‐specific single‐item question: “whether patients would choose the same type of surgery”	Medium time: 28 months since diagnosis
17	Burton 2017	UK 10 breast units in England and Wales	To assess information needs and preferences in women ≥ 75 years with early breast cancer, offered a choice between primary endocrine therapy and surgery	Cross‐sectional design using questionnaires	Women aged ≥ 75 years with early breast cancer	101	DRS Mean scores on a scale of 0–100	Up to 5 years since treatment
18	Kwok 2017	Australia A cancer support group serving the Chinese community	To explore how cultural values and language affect participation in treatment decision‐making in Chinese women	Focus groups	Chinese women with stage 0–II breast cancer	23	Interview questions	Within 6 months since diagnosis
19	Swanick 2018	USA National Medicare registry	To assess the association of local therapy with long‐term patient outcomes in older women. Decision regret is one of the outcomes	Cross‐sectional design using questionnaires	Women aged ≥ 67 years with early breast cancer	In total: 489 Surgery regret was assessed in 463 women Radiotherapy regret was assessed in 340 women	DRS Mean scores on a scale of 0–100	Average time: 6 years after diagnosis
20	Wang 2018	Taiwan, China Breast cancer outpatients from a medical center in central Taiwan	To assess the relationship between role incongruence and decision regret and whether stage and surgery type moderate this relationship	Cross‐sectional design using questionnaires	Women with stage 0–II breast cancer	154	DRS Possible range of 5–25	Median time: 18 months since surgery
21	Lee 2019	Singapore The National Cancer Centre	To explore the reasons why women who could have breast‐conserving surgery choose mastectomy and their reflections after mastectomy	Cross‐sectional design using questionnaires	Women with stage I–III breast cancer who are eligible for breast‐conserving surgery	91	Study‐specific single‐item question: “If you could choose between the 2 procedures again, would you choose breast‐conserving surgery instead?”	Median time: 48 months after mastectomy
22	Yamauchi 2019	Japan Internet‐based survey using an online marketing research company	To assess the correlates of regret with treatment decision‐making	Cross‐sectional design using questionnaires	Women with stage 0, I, II breast cancer	467	Study‐specific single‐item question: “have you had any regret or something you wanted to do over again in the treatment decision‐making process?”	54.8% within 5 years since diagnosis, 45.2% more than 5 years
23	Zdenkowski 2019	Australia 4 hospitals in NSW and VIC	To explore the impact of treatment sequence (adjuvant therapy or surgery first) and pathological response on patient‐reported outcomes. Decision regret is one of the outcomes	Longitudinal design, single‐arm	Women who had operable breast cancer	51 women at time 1 41 women at a time 2	DRS Mean scores on a scale of 0–100	Two time points: Time 1: For patients who received neoadjuvant therapy, this is after completing the therapy but before surgery. For patients who had surgery first, this is after surgery but before starting chemotherapy Time 2: 12 months after
24	Schulman‐Green 2020	USA Smilow Cancer Hospital in New Haven	To explore women's and family caregivers' considerations when making treatment decisions	Individual interview	Women with early breast cancer	22	Interview questions	Not reported
25	Durand 2021	USA 7 clinics in 4 national cancer centers across urban and rural areas	To compare a picture‐based decision aid, a text‐only decision aid, and usual care on decision quality in low socioeconomic women. Decision regret is one of the outcomes	RCT	Low socioeconomic women with stages I–IIIa breast cancer	In total: 571 Picture‐based decision aid: 248 Text‐only decision aid: 66 Usual care: 257	DRS Mean scores in a scale of 0–100	1 week, 12 weeks, and 1 year after surgery
26	Sondergaard 2021	Denmark Department of oncology at the public Lillebaelt hospital, university hospital of southern Denmark	To compare consultation length and decisions between a patient decision aid cohort and an unexposed cohort	Cohort study	Women with early breast cancer	In total: 122 Unexposed control cohort: 63 Shared decision‐ making and decision aid cohort: 59	DRS Mean scores on a scale of 0–100	6 months after the consultation

Note: DRS, decision regret scale; RCT, randomised controlled trial; UK, the United Kingdom; USA, the United States of America.

^a The number of participants in whom the decision regret was measured.

4.2. The Type of Treatment Related to Decision Regret

As shown in Table 3, breast cancer surgery is mostly examined in relation to decision regret, with three‐quarters of studies (n = 17) specifically investigating decision regret associated with undergoing either BCS or mastectomy (Boehmer, Linde, and Freund 2007; Durand et al. 2021; Goel et al. 2001; Hawley et al. 2008; Killoran and Moyer 2006; Kwok and Koo 2017; Lally 2009; Lam et al. 2013, 2014; Lee and Knobf 2015; Lee et al. 2018; López et al. 2014; Martinez et al. 2015; McVea, Minier, and Johnson Palensky 2001; Noh et al. 2008; Sepucha et al. 2015; Wang et al. 2018). However, the majority of them did not differentiate decision regret between the two types of surgeries (n = 13). Only three reported decision regret related to undergoing a mastectomy (Boehmer, Linde, and Freund 2007; Lee and Knobf 2015; Lee et al. 2018), and two reported decision regret related to undergoing a BCS (Killoran and Moyer 2006; Lee and Knobf 2015).

TABLE 3.

Findings of decision regret amongst women with early breast cancer in each study (n = 26).

No.	First author, year	Findings related to decision regret
		The type of treatment related to decision regret	The level of decision regret experienced	Factors associated decision regret
1	Goel 2001	Surgery Did not indicate the specific surgical type	Presenting the percentage of “agree” or “strongly agree” with DRS items, nearly 92.06% in the decision aid arm and 95.45% in the control arm agreed or strongly agreed with DRS item “It was the right decision”, and 2.70% vs. 11.36% for “I regret the choice that was made”, 85.71% vs. 90.91% for “I would made the same choice if given a second choice”	Decision support tools ○ No difference between the decision aid group and the control group
2	McVea 2001	Surgery	Three women were considered as “panicked” in the decision‐making process. All of them expressed regret that they had not thought through their surgical choices more carefully (one had BCS and two mastectomy)	Mental health status ○ The authors suggested that although panicked women may have been offered treatment options, they were, in reality, unable to participate in decision‐making due to emotional distress and fear, which may lead to regret
3	Killoran 2006	Surgery BCS	Not reported	Disempowerment ○ Some women stated in the focus groups, with some regret, that the doctor made the choice of BCS for them, and they felt disempowered in the process
4	Boehmer 2007	Surgery Mastectomy	Contrary to sexual minority women who chose reconstruction, those who had mastectomy but not reconstruction voiced no doubts or regrets about their choice	Not reported
5	Hawley 2008	Surgery Did not indicate the specific surgical type	Dividing the DRS into three levels based on tertiles, nearly 39% had a high level of decision regret, 30% had a moderate level of regret, and 31% reported very little regret	Ethnicity ○ Latina Spanish‐speaking women, Latina English‐speaking women, and African–American women were significantly more likely to report decision regret than Caucasian women. Latina Spanish‐speaking women had the highest odds of reporting decision regret compared to women of other races Low health literacy ○ Women with low or moderate health literacy were significantly more likely than those with high health literacy to report decision regret
6	Noh 2008	Surgery Did not indicate the specific surgical type	Using a single‐item question, nearly 77.4% of women with stage ≤ IIa would choose the same surgery again if given a second chance	In this study, results on factors related to decision regret included women with stages 0–III breast cancer but were not specific to the early stages (stage 0–IIIa), so the findings regarding factors related to decision regret were not included in the data analysis of the current review
7	Lally 2009	Surgery Did not indicate the specific surgical type	This study suggested that after treatment consultation but before treatment, most women seemed quite comfortable and certain about their decisions	Not reported
8	Step 2009	Adjuvant therapy Did not indicate the specific type	In the DRS (1–5), this study found a low decision regret with the mean DRS score of 1.64	Patient communication involvement ○ Greater patient communication involvement predicted less decision regret Age ○ Older age was associated with more decision regret Education ○ Higher education was associated with less decision regret
9	Fernandes‐Taylor 2011	Any breast cancer treatment Did not indicate the specific type	Amongst women with DCIS, 41.2% indicate regret and 58.8% with no regret. Amongst women with local breast cancer, 42.8% indicate regret and 57.2% with no regret	In this study, the results on factors related to decision regret included women with remote or regional breast cancer but were not specific to the early stages (stage 0 and local stage). As a result, the findings related to decision regret were not included in the data analysis of the current review
10	Lam 2013	Surgery Did not indicate the specific surgical type	In the DRS (0–100), the mean DRS scores (0–100) for the decision aid group were as follows: 21.4 at 1 month, 18.8 at 4 months, and 20.1 at 10 months after surgery. For the control group, the mean scores were 23.1 at 1 month, 24.4 at 4 months, and 24.6 at 10 months after surgery	Decision support tools ○ Patients in the decision aid group reported significantly lower decision regret at 4 and 10 months after surgery compared to patients in the control group. Decision regret 1 month after surgery did not differ between the groups
11	Livaudais 2013	Surgical and adjuvant treatment Did not indicate the specific type	Using a single‐item question, about 40% of women experienced decision regret six month after baseline	Women‐perceived responsibility for treatment decisions ○ Women reporting “too much” responsibility for treatment decision‐making were significantly more likely than those reporting a “reasonable amount” of responsibility to express decision regret at six month adjusting for key confounding factors
12	Lam 2014	Surgery Did not indicate the specific surgical type	Not reported	Shared decision‐making ○ Decision regret was significantly predicted by a lower quality in establishing shared decision‐making framework Decision conflict ○ Decision regret was predicted by a greater level of decision conflict Having multiple choices ○ Decision regret was predicted by being offered multiple treatment options Consultation time ○ Decision regret was predicted by a greater duration of consultation Pre‐consultation anxiety ○ Decision regret was predicted by a higher level of pre‐consultation anxiety
13	López 2014	Surgery Did not indicate the specific surgical type	Using a single‐item question, about 35% of Spanish‐speaking Latinas reported treatment regret, compared to 7% of English‐speaking Latinas and 10% of White women	Ethnicity ○ Spanish‐speaking Latinas reported higher odds of regret than English‐speaking Latinas and White women. English‐speaking Latinas and White women reported similar levels of regret Participation in decision‐making ○ Women with a more participatory decision‐making process had lower odds of regret than those reporting a less participatory process
14	Lee 2015	Surgery Mastectomy and BCS	In the DRS (0–100), the mean score regarding surgery was 29.1. Specifically, the mean DRS score was 32.9 for mastectomy and 24.8 for BCS. Most of the women reported that they would make the same decision again (72.3%)	Decisional conflict ○ Women who had a higher level of decisional conflict had significantly higher decision regret Women's expectations ○ Women who expected a greater impact of surgery on femininity, sexuality, and body image had significantly higher decision regret
15	Martinez 2015	Surgery Did not indicate the specific surgical type	In the DRS (0–20), the mean score regarding surgery for women with stage 0 was 4.43 at 9 months and 5.48 at 4 years later. For women with stage I–II, the mean score was 4.88 at 9 months and 5.29 at 4 years later	Time after diagnosis: ○ Decision regret 4 years after diagnosis was significantly higher than the levels measured 9 months after diagnosis for both women with stage 0 and stage I–II breast cancer
16	Sepucha 2015	Surgery Did not indicate the specific surgical type	Using a single‐item question, nearly 60.8% of participants would definitely have the same type of surgery again, indicating no regret, while 39% reported some regret	Decision Process Score (measuring the discussion of options, pros and cons, goals, treatment preferences, and the extent of discussion): ○ Women reporting decision regret had significantly lower total decision process scores compared to those without decision regret
17	Burton 2017	Surgery or primary endocrine therapy	In the DRS (0–100), the mean score was 14.48, indicating a low level of regret	Not reported
18	Kwok 2017	Surgery	Not reported	Poor communication with providers ○ Some women wanted to be more involved but refrained from asking questions for fear it might affect their relationship with the doctors. They followed the surgeon's advice without question, and some later felt regret ○ Some women had limited language proficiency and didn't understand information provided by the doctors and felt regret about treatment
19	Swanick 2018	Surgery or radiotherapy	In the DRS (0–100), the mean DRS score regarding surgery ranged from 13.8 in women having lumpectomy alone to 22.0 in those having mastectomy with radiotherapy. The mean DRS regarding radiotherapy ranged from 24.6 in women having lumpectomy alone to 33.4 in those having mastectomy with radiotherapy	Treatment types ○ This study examined the differences in decision regret regarding surgery and radiotherapy amongst different treatment groups and found no significant differences
20	Wang 2018	Surgery Did not indicate the specific surgical type	In the DRS (5–25), the mean score regarding surgery was 8.10, representing low rates of decision regret. Only 9.1% rated either “strongly agree” or “agree” to the statement “I regret the decision I made”	Decision role congruence ○ Those reporting decision role congruence reported significantly less regret than those reporting incongruence Surgery type ○ Women having lumpectomy reported significantly less regret than those having mastectomy Cancer stage ○ Higher stage was associated with more regret Treatment disturbance ○ More disturbance was associated with more regret
21	Lee 2019	Surgery Mastectomy	Using a single‐item question, nearly 20% would opt for breast‐conserving surgery if given a second chance, while 80% of women would insist on a mastectomy	Not reported
22	Yamauchi 2019	Any breast cancer treatment Did not indicate the specific type	Using a single‐item question, nearly 51.4% of women reported some regret, while 48.6% had no regret	Age at diagnosis ○ Women diagnosed when aged ≥ 50 years were significantly less likely to experience regret than those < 40 years Employment status ○ Women who worked on a contract or part‐time were significantly less likely to experience regret than those doing full‐time jobs Surgical type ○ Women who had mastectomy were significantly more likely to feel regret than those having BCS Patient involvement ○ Women who made their decision for cancer treatment collaboratively with their doctors were significantly less likely to experience regret than those who decided by themselves; this is particularly true for women who had a mastectomy Decisional congruence ○ In women who had BCS, those who participated in the process in their preferred role were significantly less likely to experience regret compared with those who did not participate in their preferred role Amongst women who reported regret, the most frequent regrets were issues related to “Matters concerning gathering information” (23.8%), “Not consulting with others” (21.3%), “Not considering which hospital to go” (15.4%), “Not taking the time to consider options” (13.8%), “Not building trusting relationships with doctors” (11.3%)
23	Zdenkowski 2019	Neo‐adjuvant therapy or adjuvant therapy	In the DRS (0–100), the mean score for neoadjuvant therapy ranged from 12.2 to 16.9, and from 11.7 to 20.0 for adjuvant therapy	Treatment type ○ No significant difference in decision regret between neoadjuvant therapy and adjuvant therapy
24	Schulman‐Green 2020	Surgery and adjuvant chemotherapy	Not reported	Decision regret manifesting in five ways: with postsurgical outcomes; that they could not weigh the risks of potential adverse effects; whether they should have participated in a clinical trial; not being given enough information when making a decision; and not having enough information available, including prognostic information Decision regret was mitigated by knowing what to expect, by leaving decisions to providers (for some), and by understanding their decision
25	Durand 2021	Surgery Did not indicate the specific surgical type	In the DRS (0–100): Mean DRS 1‐week post‐surgery: picture‐based decision aid: 8.1, text‐only decision aid: 10.9, and usual care: 12.9 Mean DRS 12‐weeks post‐surgery: picture‐based decision aid: 7.6, text‐only decision aid: 12.0, and usual care: 10.8 Mean DRS 1‐year post‐surgery: picture‐based decision aid 6.0, text‐only decision aid 10.4, and usual care 7.6	Decision support tools ○ Compared to usual care, patients using the Picture‐based decision aid had significantly less regret about their decisions at 1‐week post‐surgery. No differences in decision regret between interventions at other measurement times
26	Sondergaard 2021	Adjuvant therapy Did not indicate the specific type	In the DRS (0–100), the mean DRS score was 25.55 in the control cohort and 20.59 in the SDM cohort Thirty‐two (51%) patients in the control cohort and 40 patients (68%) in the SDM cohort had no or mild regret	Decision support tools ○ No significant difference in decision regret between groups

Note: BCS, breast‐conserving surgery; DCIS, ductal carcinoma in situ; DRS, decision regret scale. SDM, shared decision‐making.

There were only three studies specifically examining decision regret related to adjuvant therapies for early breast cancer. Furthermore, these studies did not specify which type of adjuvant therapy the decision regret was associated with (e.g., chemotherapy or radiotherapy) (Søndergaard et al. 2021; Step et al. 2009; Zdenkowski et al. 2019). One additional study examined and compared decision regret related to surgery and radiotherapy (Swanick et al. 2018). Other five studies considered various breast cancer treatments as a whole without differentiating decision regret by treatment type (Burton et al. 2017; Fernandes‐Taylor and Bloom 2011; Livaudais et al. 2013; Schulman‐Green et al. 2020; Yamauchi, Nakao, and Nakashima 2019).

4.3. The Level of Decision Regret

Nineteen studies reported the level of decision regret experienced by women with early breast cancer. Of these, 10 studies provided the mean DRS score, and nine studies presented the proportions of women experiencing decision regret (Burton et al. 2017; Durand et al. 2021; Fernandes‐Taylor and Bloom 2011; Goel et al. 2001; Hawley et al. 2008; Lam et al. 2013; Lee and Knobf 2015; Lee et al. 2018; Livaudais et al. 2013; López et al. 2014; Martinez et al. 2015; Noh et al. 2008; Sepucha et al. 2015; Søndergaard et al. 2021; Step et al. 2009; Swanick et al. 2018; Wang et al. 2018; Yamauchi, Nakao, and Nakashima 2019; Zdenkowski et al. 2019).

Amongst the 10 studies reporting the mean DRS score, the majority of them (n = 7) found a low average level of decision regret. For example, a cross‐sectional study measured decision regret amongst 154 women with stage I–II breast cancer 18 months after breast cancer surgery (Wang et al. 2018). This study found that the mean DRS score was 8.10 (range 5–25), suggesting a low level of decision regret. Three studies reported an average DRS score greater than 25, indicating a relatively high level of decision regret amongst participants. They were: Lee and Knobf (2015) investigated decision regret regarding surgery in 122 Chinese‐American women with early breast cancer and reported a mean DRS score of 29.1 (range 0–100) (Lee and Knobf 2015). Swanick et al. (2018) investigated decision regret regarding surgery and radiotherapy in 489 women aged 67 years and found a relatively high mean DRS score of 33.4 (range 0–100) related to radiotherapy in women who underwent mastectomy with radiotherapy (Swanick et al. 2018). Søndergaard et al. (2021) compared decision regret regarding adjuvant therapy in women with breast cancer between a cohort of women receiving an intervention promoting shared decision‐making (n = 59) and a cohort without this intervention (n = 63). The study found a relatively high DRS score of 25.55 (range 0–100) in the unexposed cohort but a lower DRS score of 20.59 in the intervention cohort (Søndergaard et al. 2021).

The nine studies examining the proportions of women experiencing regret showed high variation, with the reported rates ranging from as low as 2.7% (Goel et al. 2001) to as high as 69% (Hawley et al. 2008). The lowest rate was found in an RCT that examined the impact of a decision aid in women with early breast cancer. In this study, nearly 2.7% of 63 women in the decision aid group agreed or strongly agreed with the statement “I regret the choice that was made” 6 months after surgery (Goel et al. 2001). The highest rate was reported in a cross‐sectional survey examining surgery‐related decision regret amongst 877 women of various ethnicities (Caucasians, Latinas, and African Americans). This study categorised the DRS into three levels (low, moderate, and high) based on the tertiles of the scale. Nearly 69% of participants reported moderate to high levels of regret, while only 31% reported low decision regret (Hawley et al. 2008).

4.4. Factors Associated With Decision Regret

Eighteen studies reported on factors associated with decision regret in women with early breast cancer (Durand et al. 2021; Goel et al. 2001; Hawley et al. 2008; Killoran and Moyer 2006; Kwok and Koo 2017; Lam et al. 2013, 2014; Lee and Knobf 2015; Livaudais et al. 2013; López et al. 2014; McVea, Minier, and Johnson Palensky 2001; Schulman‐Green et al. 2020; Sepucha et al. 2015; Søndergaard et al. 2021; Step et al. 2009; Swanick et al. 2018; Wang et al. 2018; Yamauchi, Nakao, and Nakashima 2019). These factors were narratively synthesised within three categories based on their similarities: (1) socio‐demographic and clinical factors, (2) decision‐making experiences, and (3) mental health.

4.4.1. Socio‐Demographic and Clinical Factors

4.4.1.1. Age

Two studies found significant associations between age and decision regret (Step et al. 2009; Yamauchi, Nakao, and Nakashima 2019). Yamauchi, Nakao, and Nakashima (2019) found that women older than 50 years at the time of diagnosis were less likely to report regret regarding surgery than those younger than 40 at the time of diagnosis (adjusted OR = 0.44, 95% CI = 0.21–0.94, p < 0.05) (Yamauchi, Nakao, and Nakashima 2019). Step et al. (2009) found a small effect of patient age on regret regarding adjuvant therapies (estimated coefficient = 0.01, p < 0.01), suggesting that older age is associated with higher decision regret (Step et al. 2009).

4.4.1.2. Ethnicity

Two studies in the United States found that women with minority ethnicities were significantly more likely to experience decision regret (Hawley et al. 2008; López et al. 2014). Hawley et al. (2008) found that Spanish‐speaking Latina women, English‐speaking Latina women, and African American women were significantly more likely than Caucasian women to report decision regret. Amongst them, Spanish‐speaking Latina women had the highest odds of reporting decision regret compared to Caucasian women (adjusted OR = 4.1, 95% CI = 2.2–8.0, p < 0.05) (Hawley et al. 2008). Similarly, in López et al. (2014), Spanish‐speaking Latinas were more likely to report decision regret than English‐speaking Latinas and Caucasians (adjusted OR = 4.5, 95% CI = 2.2–9.0, p < 0.05) (López et al. 2014).

4.4.1.3. Employment

One study found that amongst women with BCS, those working full‐time were significantly more likely to experience regret in decision‐making than those employed on a contract or part‐time basis (aOR = 0.51, 95% CI = 0.29–0.89, p < 0.05) (Yamauchi, Nakao, and Nakashima 2019).

4.4.1.4. Education

One study found a small effect of patient education on decision regret regarding adjuvant therapies (estimated coefficient = −0.03, p < 0.01), suggesting that higher education was associated with lower decision regret (Step et al. 2009).

4.4.1.5. Health Literacy

One study found that women with low or moderate health literacy were significantly more likely than those with high health literacy to report decision regret regarding surgery (aOR = 3.5, 95% CI = 1.8–7.1, p < 0.01; aOR = 2.1, 95% CI = 1.4–3.1, p < 0.01, respectively) (Hawley et al. 2008).

4.4.1.6. Cancer Stage

One study in women with stage 0–II breast cancer found that a higher stage of disease was associated with more decision regret regarding breast cancer surgery (r = 0.16, p = 0.05) (Wang et al. 2018).

4.4.1.7. Treatment Types

Two studies consistently reported that women having a mastectomy had significantly higher levels of regret than those with BCS (Wang et al. 2018; Yamauchi, Nakao, and Nakashima 2019). Another study compared decision regret concerning surgery versus radiotherapy amongst women older than 67 years and found no significant difference (Swanick et al. 2018).

4.4.2. Decision‐Making Experiences

4.4.2.1. Patient Involvement

Five quantitative studies reported that increased patient involvement in decision‐making was associated with reduced decision regret (Lam et al. 2014; López et al. 2014; Sepucha et al. 2015; Step et al. 2009; Yamauchi, Nakao, and Nakashima 2019). For example, Step et al. (2009) showed that greater patient involvement in communication during the decision‐making process predicted lower regret regarding adjuvant therapy decisions (p = 0.02) (Step et al. 2009). In another qualitative study, some women expressed regret that the doctor made the choice of BCS for them, and they felt disempowered in the process (Killoran and Moyer 2006).

4.4.2.2. Patient Preference

Two studies found that women who participated in the decision‐making process to the extent they had expected reported significantly lower decision regret than those whose participation did not match their expectations (Wang et al. 2018; Yamauchi, Nakao, and Nakashima 2019). For example, in Wang et al. (2018) study, women who felt their actual participation in decision‐making matched their preferences (decisional role congruence) reported significantly less regret compared to those who felt they were either more involved or less involved in decision‐making than what they preferred (decisional role incongruence) (Wang et al. 2018). Sepucha et al. (2015) found that women who received the type of surgery aligned with their goals were about twice as likely to have no regret compared to those women who had not received surgery aligned with their goals (Sepucha et al. 2015). Lee and Knobf (2015) found that women who expected a more significant impact of surgery on their femininity, sexuality, and body image experienced higher levels of decision regret (Lee and Knobf 2015). Livaudais et al. (2013) found that women who reported feeling “too much” responsibility for treatment decision‐making were significantly more likely than those reporting a “reasonable amount” of responsibility to experience decision regret (Livaudais et al. 2013).

4.4.2.3. Accessing Information About Treatment

Two qualitative studies found that decision regret was related to information access about treatment options (Kwok and Koo 2017; Schulman‐Green et al. 2020). In a qualitative study, Kwok and Koo (2017) reported that some women who were reluctant to ask questions about their treatment options felt regret about the decision for BCS (Kwok and Koo 2017). Another qualitative study found that women who felt they were not provided with sufficient information during the decision‐making process experienced regret about their decision (Schulman‐Green et al. 2020). Besides, Yamauchi, Nakao, and Nakashima (2019) reported that the process of gathering information was the most frequently reported experience that women felt regretful about (23.8%) (Yamauchi, Nakao, and Nakashima 2019). This study did not provide detailed information on this regret.

4.4.2.4. Decision Support Tools

Four quantitative studies examined the impact of using decision support tools in the decision‐making process on post‐treatment decision regret (Durand et al. 2021; Goel et al. 2001; Lam et al. 2013; Søndergaard et al. 2021). Two found no significant difference, and the other two studies found that women using decision support tools experienced reduced decision regret after treatment (Durand et al. 2021; Goel et al. 2001; Lam et al. 2013; Søndergaard et al. 2021).

Lam et al. (2013) developed a take‐home booklet detailing the main differences amongst the available treatment options, benefits and negative features of the available treatment options, and a personal worksheet format facilitating value clarification and structured guidance resulting in either current surgical preference or unresolved decision outcomes and suggested next steps (Lam et al. 2013). This study found that women in the intervention group reported significantly lower levels of decision regret at 4 and 10 months post‐surgery (Lam et al. 2013). Durand et al. (2021) compared regret in three groups of women. One group received a decision aid containing pictures, another, a decision aid containing text without pictures, and the last group, usual care (Durand et al. 2021). This study reported that women from the picture‐based decision aid group reported significantly lower regret than those from the text‐only aid and usual care groups, especially for lower socioeconomic status and health literacy subgroups (Durand et al. 2021). However, Goel et al. (2001) developed a decision support tool that contained an audiotape and a booklet with numbers, photographs, graphics, or value‐clarification exercises. They investigated whether using this aid would benefit women with higher‐quality decisions (Goel et al. 2001). This study found no significant difference in decision regret after using this tool compared to a trifold educational pamphlet without numbers, photographs, graphics, or value‐clarification exercise. Another prospective cohort study examined regret regarding adjuvant therapy between cohorts who received a decision aid to promote shared decision‐making and a control cohort (Søndergaard et al. 2021). They found no significant difference in decision regret between cohorts (Søndergaard et al. 2021).

4.4.3. Mental Health

Three quantitative studies found a significant positive association between mental health issues and decision regret, which included decisional conflict (Lam et al. 2014; Lee and Knobf 2015), pre‐consultation anxiety (Lam et al. 2014), and disturbances caused by breast cancer and treatment (Wang et al. 2018). For example, Lam et al. (2014) found that higher pre‐consultation anxiety and greater decisional conflict 1 week after consultation significantly predicted higher decision regret at 1 month post‐surgery (p < 0.05) (Lam et al. 2014). In another qualitative study, McVea, Minier, and Johnson Palensky (2001) found that all women who were fearful and distressed when making treatment decisions expressed decision regret after treatment. These women reported that they did not adequately consider their surgical choices (McVea, Minier, and Johnson Palensky 2001). This study also suggested that emotional distress and fear impaired women's ability to participate in and understand the treatment options, which subsequently led to decision regret.

5. Discussion

This review synthesises existing evidence on decision regret amongst women with early breast cancer. It identified the type of treatment associated with decision regret and revealed a wide range of reported decision regret levels. It also identified various socio‐demographic and clinical factors, decision‐making experiences, and mental health conditions associated with decision regret. To the best of the researchers' knowledge, this review is the first to provide a comprehensive understanding of decision regret regarding treatment in women with early breast cancer. The findings are essential for nurses and other healthcare professionals to identify women at risk of reporting decision regret and support them in treatment decision‐making, which can reduce decision regret and its negative impact on other health outcomes.

This review found that the majority of existing studies (17 out of 26) investigated decision regret related to the choice of undergoing breast cancer surgery (BCS or mastectomy). However, most of these studies (13 out of 17) did not disaggregate decision regret by the type of surgery. Surgical procedures remain the primary method for treating early breast cancer (Benson et al. 2009; Gradishar et al. 2022). Since BCS and mastectomy have been demonstrated to provide comparable survival outcomes for early breast cancer (Clarke et al. 2005; Gradishar et al. 2022; Veronesi et al. 2002), women are often required to choose between the two options (Liu et al. 2021). Therefore, future research is needed to investigate decision regret with more specific surgical options, which could advance our understanding and help women avoid decision regret when selecting their surgical treatment.

Although only a limited number of studies (n = 2) have compared decision regret by surgical type, these studies consistently indicate that women who undergo mastectomy are more likely to experience decision regret compared to those who undergo BCS. Mastectomy is a procedure that involves the removal of the entire breast and sometimes along with the lymph nodes. Compared to BCS, mastectomy can pose greater physical challenges for women, such as more severe pain (caused by the removal of a larger area of tissue) and an increased risk of lymphedema (caused by the removal of lymph nodes). Moreover, mastectomy is associated with greater body disfigurement than BCS, which can lead to a higher likelihood of experiencing body image disturbances, emotional distress, worse sexual health, and poorer quality of life (Rosenberg et al. 2020; Thakur et al. 2022; Zehra et al. 2020). These post‐mastectomy challenges may prompt women to question the necessity of their choice and wonder if the outcomes might have been more favourable had they chosen BCS, thereby increasing decision regret. Therefore, when discussing treatment options, nurses and other healthcare professionals should thoroughly explain the potential benefits and drawbacks of each option, enabling women to make informed decisions and better prepare for the possible outcomes, especially for those considering mastectomy.

This review also found that only a limited number of studies (n = 3) have specifically examined decision regret in relation to adjuvant therapies. While surgery has traditionally been the primary treatment for early breast cancer, adjuvant therapies are becoming an increasingly integral component of its management (Benson et al. 2009; Gradishar et al. 2022). More research investigating decision regret in this context is thus needed.

Overall, most studies included in this review reported low levels of decision regret in women with early breast cancer. This finding is consistent with previous reviews on decision regret about breast reconstruction and risk‐reducing mastectomy (Braude et al. 2017; Flitcroft, Brennan, and Spillane 2018). Also, the proportion of women who experienced decision regret about treatments ranged from 2.7% to 69%. This broad range may be attributed to differences in study design. For example, the lowest rate was reported by a group of women receiving decision aid in an RCT, while the highest rate was found in a cross‐sectional survey. Moreover, variations in the measurement of decision regret may contribute to this broad range. For example, some studies reported the percentage of responses to DRS items, while others used study‐specific single‐item questions with binary responses. Nonetheless, research has found that women with breast cancer often experience stigma (Melhem, Nabhani‐Gebara, and Kayyali 2023; Wu et al. 2023), which may impact the sharing of their negative emotions. The reported decision regret after treatment is thus likely to be underestimated (Thornton, Edalatpour, and Gast 2024). Therefore, we recommend caution in interpreting this finding and suggest a future meta‐analysis to provide more precise estimates of decision regret levels in women with early breast cancer. Since decision regret is associated with other poor healthcare outcomes, such as self‐recrimination and poor well‐being (Groopman and Hartzband 2017; Xu, Zhou, and Wang 2021), in clinical practice, we recommend that nurses and other healthcare professionals be aware of the occurrence of decision regret and provide adequate support in women's treatment decision‐making processes to minimise decision regret.

A range of socio‐demographic, clinical, decision‐making experiences, and mental health factors associated with decision regret were identified in this review. Amongst these, the number of studies examining socio‐demographic and clinical factors and their influence on decision regret is relatively limited (fewer than three studies), indicating a need for more research in this field. This review found mixed results regarding age and its effect on decision regret. This inconsistency may be due to the limited number of studies (only two) and the different treatments examined (one in surgery and one in adjuvant therapy). As women age, they may have different preferences and experiences in the treatment decision‐making process (Hamelinck et al. 2018; Sio et al. 2014). Therefore, when guiding treatment decision‐making, nurses and other healthcare professionals need to consider different approaches to address the varied needs of women at different ages to minimise decision regret.

This review found that in the United States, women of (Latina and African‐American women) were significantly more likely to experience decision regret compared to Caucasian women. Researchers have suggested that it may be related to language barriers and poor communication with healthcare professionals, resulting in poorer decision outcomes amongst these women (Hawley et al. 2008; López et al. 2014). Previous studies on breast cancer have also shown that women from ethnic minorities are at a higher risk of having inadequate health literacy (Moore and Hayes 2023), potentially affecting their understanding of treatment information and thereby increasing decision regret. This explanation is also supported by other findings from this review: lower health literacy and educational attainment were associated with higher decision regret. Thus, we recommend that nurses and other healthcare professionals use plain language and provide educational materials in the native languages of women from ethnic minorities during treatment consultations, which would improve communication and reduce decision regret. Similar strategies should be considered for women from other ethnic minority groups and those living in ethnically diverse societies.

This review found that women's decision‐making experiences play a significant role in influencing decision regret. Greater involvement in the decision‐making process, being actively engaged as expected, and undergoing the preferred type of surgery were associated with lower levels of decision regret. Reluctance to ask questions and a lack of understanding of treatment information contributed to higher levels of decision regret. These findings support promoting the shared decision‐making model in clinical consultations to enhance decision outcomes (Chichua et al. 2022; Elwyn et al. 2012). Elwyn et al. (2012) proposed three key steps to implement the shared decision‐making model: introducing choice (choice talk), describing options (option talk), and understanding and eliciting preferences (decision talk) (Elwyn et al. 2012). Our results resonate with those of Elwyn et al. (2012) and suggest that promoting these components in clinical settings can help minimise decision regret, while omitting any of them may lead to decision regret. When making treatment recommendations, nurses and other healthcare professionals should consider a combination of strategies, including understanding women's preferences, encouraging them to ask questions and actively participate in the decision‐making process, and providing clear information about treatment options to help reduce decision regret (Chichua et al. 2022).

Decision regret poses a significant psychological burden for women and is linked to other adverse healthcare outcomes, such as poorer well‐being and reduced quality of life (Groopman and Hartzband 2017; Xu, Zhou, and Wang 2021; Zhuang et al. 2022). However, this review found that few interventions (decision support tools) were designed to address decision regret in early breast cancer (only four studies), and the findings regarding their effectiveness on decision regret were inconsistent. These inconsistencies may stem from differences in the design of the interventions and the types of treatments studied. While incorporating interventions into treatment decision‐making has shown promise in improving women's understanding of their options, reducing decisional conflict, and enhancing the quality of life (Coronado‐Vázquez et al. 2020; Si et al. 2020; Vromans et al. 2019), their effectiveness on decision regret amongst women with early breast cancer requires further investigation through more robust interventional studies.

This review found that women with pre‐treatment mental health challenges are more likely to experience decision regret. Similarly, Szproch and Maguire (2022) reviewed regret in patients with various cancers, reporting that regret following cancer treatment was associated with poor mental health, including higher anxiety, depression, and emotional distress (Szproch and Maguire 2022). Mental health issues, such as fear and emotional distress, can impact women's ability to make autonomous decisions and carefully consider their options (Liu et al. 2024). This impairment may lead to treatments that are not aligned with the women's preferences, thereby causing decision regret. Hence, this review highlights the importance of nurses and other healthcare professionals identifying women who experience mental health issues and incorporating mental health interventions during treatment consultations, which may help reduce the occurrence of decision regret.

One limitation of this review is that it focuses on early breast cancer, so the findings cannot apply to advanced stages. Besides, this review is based on studies published in English; thus, evidence from studies using other languages may be missing. Lastly, due to the nature of integrative reviews, this study could not provide an accurate estimation of the level of decision regret in early breast cancer.

6. Conclusions

This review found that surgery is the most commonly examined treatment in relation to decision regret in early breast cancer, whereas adjuvant therapy has been studied much less frequently. Although low levels of decision regret were reported in most included studies, the proportion of women experiencing decision regret varied significantly. Several socio‐demographic and clinical factors (including age, ethnicity, employment, education, health literacy, cancer stage, and treatment types) were identified as being associated with decision regret. This review also highlights that promoting shared decision‐making and addressing women's mental health during the treatment decision‐making process can help reduce decision regret. It is recommended that nurses and other healthcare professionals consider these factors and strategies when supporting women in making treatment decisions to minimise regret. Future studies should disaggregate decision regret by treatment type to advance the understanding of decision regret about treatment in early breast cancer. More robust evidence is needed to explore decision regret related to adjuvant therapy and assess the effectiveness of decision support tools in reducing decision regret amongst women with early breast cancer.

Author Contributions

All authors conceived this study. Jing Liu and Sharyn Hunter conducted the study selection, quality assessment, and data analysis. All authors validated the data analysis process and data interpretation. Sally Wai‐Chi Chan, Regina Lai Tong Lee, Sharyn Hunter, and Jiemin Zhu supervised this research project. Jing Liu drafted the initial manuscript, and all authors made substantial revisions to it. All authors have reviewed and approved the final manuscript.

Conflicts of Interest

The authors declare no conflicts of interest.

Peer Review

The peer review history for this article is available at https://www.webofscience.com/api/gateway/wos/peer‐review/10.1111/jan.16767.

Supporting information

Data S1.

Data Availability Statement

This work is an integrative review without statistical analysis. The data that support the findings of this study are available from the corresponding author upon reasonable request.