Quality of life, insomnia, attitudes and beliefs in women undergoing chemotherapy for breast cancer: a cross-sectional study in Amol city Northern Iran

Abstract

Background

Breast cancer is the most common disease in women worldwide, and it can cause serious physical and psychological problems, particularly in Iran, where it accounts for 23.6% of all malignancies in women. The goal of the current study was to examine the quality of life, insomnia, attitudes and beliefs in women undergoing chemotherapy for breast cancer.

Methods

A correlational study among 468 breast cancer patients (Stages I–III) selected through convenient sampling in northern Iran was conducted in 2024 to measure quality of life (QoL), insomnia, and patients’ attitudes and beliefs toward cancer via the EORTC QLQ-C30, the Insomnia Severity Index (ISI), and the Cancer Attitude and Belief Questionnaire, respectively. Validity and reliability of all instruments were confirmed via content validity index and Cronbach’s α respectively. Normality of data was assessed via kurtosis, skewness and Q-Q plots. The data analysis was performed via SPSS Version 24.0 through ordinal logistic regression analyses and Gamma–Cramer correlations.

Results

The individuals (mean age: 45.03 ± 10.57 years) had a high quality of life (81.46 ± 21.4) and mild insomnia (10.54 ± 5.86). QoL was significantly negatively correlated with both insomnia (r=-0.147; p value < 0.05) and patients’ attitudes/beliefs toward cancer (r=-0.653; p value < 0.05). Low socioeconomic status had a substantial impact on low QoL (OR = 16.94, p < 0.001) and higher levels of insomnia (OR = 0.35, p = 0.024).

Conclusion

This study emphasizes the need for comprehensive, culturally responsive healthcare treatments by highlighting the many aspects that affect the quality of life of patients with breast cancer receiving chemotherapy, as more than half of the patients reported insomnia problems.

Introduction

Globally, lung cancer was the most frequently diagnosed cancer, with 2.5 million new cases representing 12.4% of all newly reported cancers. This was followed by female breast cancer with 2.3 million cases (11.6%), and colorectal cancer with 1.9 million cases (9.6%) [1]. Compared with other malignancies, breast cancer has the greatest incidence, death rate and most commonly diagnosed worldwide [2, 3]. Over the course of the last four decades, the incidence of breast cancer has increased. The rate has increased by 0.5% per year over the past ten years [4]. This rise is especially alarming in Iran, where breast cancer makes up 23.6% of all cancers in women, a sign of changing demographics and lifestyle choices [4]. As per the recent data, breast cancer is the fifth most common cause of cancer-related deaths in Iran, and by 2030, the age-standardized incidence rate (ASIR), which is currently 35.8 per 100,000, is expected to rise to nearly 70 per 100,000 [5].

A diagnosis of cancer can elicit significant psychological anguish and is a life-altering event [6]. For many women, breast cancer is the most distressing of the several types of cancer, and this increased suffering can take many different forms [7]. Breast cancer patients’ quality of life (QoL) is significantly impacted by the symptoms of the disease as well as the side effects of treatment therapy [8]. The patient’s overall quality of life is affected physically by the treatment plan, whereas the diagnosis of cancer has many psychological effects [9]. Quality of life, a multifaceted and intricate concept, is influenced by variety of factors [8]. Among this insomnia, attitude and belief regarding disease and treatment therapy stands out as a predictive element affecting the patient’s quality of life and managing the conditions of women with breast cancer undergoing chemotherapy [10, 11]. Therefore, enhancing the quality of life of cancer patients receiving chemotherapy is a top priority for clinicians and researchers.

The frequency of sleep disturbances in breast cancer patients is an important issue that arises regularly in this context [12]. Sleep difficulties affect approximately 40% of female patients with breast cancer, according to one comprehensive review and can lead to many consequences, including social impairment, fatigue, mood swings, poor work performance, and dependence on sleeping pills [10, 13]. Additionally, insomnia is worsened by the side effects of cancer therapy. Along with insomnia, one of the greatest psychological and emotional challenges that women with breast cancer face throughout chemotherapy is the negative thoughts associated with malignancy and this depends on their attitude and belief regarding cancer and its treatment, which often be more unbearable than the illness or the treatments used [14, 15]. Furthermore, there is a bidirectional relationship between quality of life, insomnia, and patients’ attitudes and beliefs, where a decline in quality of life is associated with increased severity of insomnia and more negative attitudes and beliefs. In turn, negative attitudes and beliefs can further exacerbate insomnia, creating a cyclical impact on quality of life [16].

Despite the growing emphasis on patient-centered care and survivorship around the world, not much researches have been done on the intricate relationships between quality of life, insomnia, psychological factors like attitudes and beliefs. Additionally, the lack of region-specific data on the interconnected experiences of QoL, insomnia, attitudes, and belief among women with breast cancer undergoing chemotherapy in Northern Iran is the reason for the necessity of this study. Hence it is necessary to examine these aspects within these specific regional contexts. This cross-sectional study fills important gaps by examining the relationships between quality of life, insomnia, attitudes and beliefs in women undergoing chemotherapy for breast cancer.

Methods

Study design

The researchers conducted a cross-sectional, descriptive correlational study to investigate factors affecting women undergoing chemotherapy for breast cancer. This type of study design was chosen to capture information of the variables of interest and to determine relationships among them without manipulating any variables.

Study setting and population

The study was carried out among women undergoing chemotherapy for breast cancer referred to selected hospitals and outpatient oncology clinics located at the Arian Clinic, in Amol city, Mazandaran Province, northern Iran. These healthcare centers were selected based on their patient volume and accessibility to ensure a representative sample of the regional population. Data collection was conducted over a six-month period, from July to December 2024.

Inclusion criteria

Participants were selected based on the following inclusion criteria: (i) female patients aged 18 years and older, (ii) histologically confirmed non-metastatic breast cancer (Stages I–III), (iii) patients who were either currently receiving or scheduled to receive chemotherapy treatment, (iv) provided informed consent for participation in the study.

Exclusion criteria

Patients were excluded from the study if they met any of the following conditions: i: presence of significant psychiatric disorders (such as major depression, bipolar disorder, or schizophrenia), ii) diagnosis of non-cancer-related chronic conditions that could independently affect the study outcomes (e.g., severe anemia, chronic pain syndromes), iii) concurrent use of medications known to impact sleep or psychological well-being, such as sedatives, antipsychotics, or stimulants, iv) employment involving night-shift work, as such work schedules can independently disrupt circadian rhythms and sleep patterns, thus confounding the study findings.

Sampling technique and sample size

This study included 468 women with breast cancer undergoing chemotherapy, recruited through convenience sampling due to feasibility constraints in a single-center setting and to maximize participation during treatment visits. The required sample size was calculated using G*Power software version 3.1.9.7, based on a two-tailed test, an alpha of 0.05, a power of 0.90, and a correlation coefficient of 0.16 from a previous study [16]. The minimum sample size was determined to be 406. To account for potential dropouts or incomplete data, a 15% increase was applied, resulting in a final target of 467 participants.

Research instruments

The data collected included demographic information (age, marital status, occupation, place of residence, education level, economic status, family history of illness, and duration of cancer), quality of life according to the EORTC QLQ-C30 (European Organization for Research and Treatment of Cancer), insomnia according to the Insomnia Severity Index Questionnaire (ISI), and patients’ attitudes and beliefs according to the Cancer Attitude and Belief Questionnaire.

EORTC QLQ-C30

The quality of life (QoL) of women undergoing chemotherapy for breast cancer was evaluated via the EORTC QLQ-C30 (version 3), which consists of 30 items across three subscales: global health status/QoL; functional scales (covering physical, role, cognitive, emotional, and social aspects); and symptom scales (covering fatigue, pain, nausea/vomiting, insomnia, etc.) [17]. The global health/QoL assessment used a 7-point Likert scale, whereas the symptom and functional items used a 4-point scale. According to the EORTC standards [18], scores were also converted from 0 to 100 and interpreted so that higher functional/global scores denoted better outcomes and higher symptom ratings denoted greater burdens. Excellent reliability was demonstrated by the validated Persian adaptation [19, 20]. In this study, the reliability of this questionnaire was assessed via the calculation of Cronbach’s alpha coefficient and was reported as 0.88 for overall quality of life.

Insomnia severity index questionnaire (ISI)

The Insomnia Severity Index (ISI) was used to assess the level of insomnia. The ISI questionnaire contains seven items, which include difficulty in starting sleep and problems with staying asleep (waking up at night and waking up early in the morning), satisfaction with the current sleep pattern, and interference with daily functioning. The questionnaire helps to evaluate the severity of the damage attributed to the sleep problem and the degree of confusion or worry caused by the sleep problem and is estimated on a 5-point Likert scale (0 = never and 4 = very much). The total score (0–28) of this questionnaire was categorized as follows: 0–7 = clinically significant insomnia, 14–8 = below the clinical threshold, 21–15 = moderate clinical insomnia, and 28–22 = severe clinical insomnia [21]. The validated Persian-translated version of the ISI is highly valid and reliable [22, 23]. The present study’s internal consistency with this research tool was similarly good (α = 0.80).

Cancer attitude and belief questionnaire

The researchers assessed attitudes and beliefs toward cancer via the questionnaire developed by Cho et al., which consists of 12 items in three domains: (a) impossibility of recovery; (b) stereotypes; and (c) discrimination, each with four questions related to the impossibility of recovery, stereotypes, and discrimination. The data were collected via a Likert scale (1 = completely disagree, 2 = disagree, 3 = agree, and 4 = completely agree). After the scores of the questions were summed, a total score between 12 and 48 was obtained. The higher the participants’ scores for each dimension are than the mean values are, the more negative the attitude toward cancer and the greater the degree of stigma [24]. In a study by Shervin Badihian, the internal consistency of the questionnaire items in the study sample was satisfactory, with Cronbach’s alpha coefficients for the impossibility of recovery, stereotypes, and discrimination of 0.67, 0.38, and 0.66, respectively [25]. In the present study, the internal consistency of this research tool was similarly good: 0.70, 0.85, and 0.72.

Data collection procedure

After receiving a permission letter from the research committee and head of institution, the researcher collected samples from women undergoing chemotherapy for breast cancer as the research population. The researchers used a convenient sampling method to choose participants after informed consent was obtained from the research participants. Each participant was thoroughly informed about the study’s objectives and procedures, with clear assurances regarding the protection of their anonymity and the confidentiality of their data. Additionally, they were explicitly made aware that their participation was entirely voluntary and that they could withdraw from the study at any time without any negative consequences. Following this, self-administered questionnaires were distributed to a total of 468 participants. To facilitate data collection, three trained researchers were assigned to the task. These researchers underwent comprehensive training covering the study’s objectives, methodology, inclusion and exclusion criteria, and ethical considerations. Moreover, the training sessions included instructions on how to collect data from illiterate participants data collection and these researchers assisted illiterate participants in completing questionnaires.

Statistical analysis

The data were analyzed with IBM SPSS (Statistical Package for the Social Sciences) version 24 statistical software. Data normality was evaluated via kurtosis, skewness and Q-Q plots. Nonparametric tests (Gamma/Cramer’s) were used for skewed data. Descriptive statistics (frequency, percentage and mean) were used for demographic variables. Gamma and Cramer’s correlation coefficients were employed to determine the relationships between variables (insomnia, QoL, and attitudes/beliefs toward cancer). The rank logistic test was used to investigate the predictors of the variables. P values less than 0.05 were regarded as statistically significant.

Results

Sociodemographic characteristics

The findings shown in Table 1 revealed that the mean age of the women undergoing chemotherapy for breast cancer included in this study was 45.03 ± 10.57 years, with the majority belonging to the 31–50 years age group. In the study population, 31.8% of women had a university education. The majority were married (79.3%), with 62% living as wives alone. Occupationally, half (50%) were housewives, followed by employees (25.6%) and freelancers (21.6%), while 26.3% reported a low income, and 5.6% lived alone. Economically, 68.6% were categorized as moderate-income families, whereas 64.5% lived in cities. The majority (77.8%) reported disease lasting less than 3 years (≤ 1 year: 39.75%; 1–3 years: 38%). Additionally, 70.1% had a family history of the disease. Data were collected from illiterate participants as trained research assistants read questions and recorded responses for them.

Table 1.

Demographic characteristics of the study participants (n = 468)

Demographic characteristics	n (%)
Patients’ age
21–30 Year	32(6.8)
31–40 Year	151(32.3)
41–50 Year	149(31.8)
51–60 Year	92(19.7)
> 60 Year	44(9.4)
Level of Education
Illiterate	77(16.5)
Less than High School	91(19.4)
Diploma	151(32.3)
University	149(31.8)
Duration of illness
< 1 Year	186(39.75)
1–3 Year	178(38)
3–6 Year	69(14.75)
> 6Year	35(7.5)
Family history
Yes	328(70.1)
No	140(29.9)
Economic status
Weak	123(26.3)
Moderate	321(68.6)
Good	24(5.1)
Place of Residence
City	302(64.5)
Rural	166(35.5)
Life status
Wife	290(62)
Wife and children	53(11.3)
Parents	67(14.3)
Child	32(6.8)
Lonely	26(5.6)
Marital Status
Married	371(79.3)
Single	42(9)
Divorced	28(6)
Widow	27(5.8)
Job
Housewife	234(50)
Employee	120(25.6)
Freelance job	101(21.6)
Retired	13(2.8)

Note: n = Number of participants;

Interrelationship between quality of life, insomnia, attitude and belief

Table 2 displays the descriptive statistics, frequency distributions, and interrelationships between the outcome variables. The findings revealed that the overall mean score of insomnia was 10.54 ± 5.86, the mean score of quality of life was 81.46 ± 21.4, and the mean score of the cancer attitudes and beliefs questionnaire was 21.23 ± 5.18. The frequency distributions also revealed that the majority reported “below threshold” insomnia (50.6%) and “excellent” quality of life (63.7%). The study revealed a statistically significant modest negative correlation between insomnia and QoL (r=-0.147, p < 0.05) and a strong negative correlation between QoL with patients attitudes and beliefs related to cancer (r=-0.653, p < 0.01). There was a small positive correlation between patients’ attitudes and beliefs related to cancer and insomnia (r = 0.183, p < 0.05).

Table 2.

The mean score, standard deviation, and correlations among the outcome variables (n = 468)

Variable	Insomnia				Quality of life			Attitude and belief toward cancer
Possible score	0–28				30–126			12–48
Observed score	1–28				36–126			12–37
Mean (SD)	10.54 (5.86)				81.46 (21.4)			21.23 (5.18)
Category	No significant	Below threshold	Moderate	High	Low	Moderate	High	Strongly disagree	Disagree	Agree
n (%)	140 (29.9)	237 (50.6)	60 (12.8)	31 (6.6)	62 (13.2)	108 (23.1)	298 (63.7)	303 (64.7)	134 (28.6)	31 (6.6)
Correlation among outcome variable
Insomnia	—				—			—
Quality of Life	-0.147*				—			—
Attitude and belief toward cancer	0.183*				-0.653**			—

Note: SD = standard deviation; *p < 0.05; ** p < 0.01, n = Number of participants,

Correlations of the socio-demographic characteristics and outcome variables

Table 3 compares the correlations of the demographic characteristics and outcome variables (QoL, insomnia, attitudes and beliefs) with Cramer’s V (nominal variables) and Gamma (rank variables). Rank factors revealed that age was positively correlated with insomnia (Gamma = 0.184, p = 0.001) and patients’ attitudes toward and beliefs about cancer (Gamma = 0.153, p = 0.02) but negatively correlated with QoL (Gamma=-0.146, p = 0.01). A lower economic status was correlated with a lower QoL (Gamma=-0.373, p = 0.001) and increased insomnia (Gamma = 0.184, p = 0.016). A longer disease duration was correlated with a greater QoL (Gamma = 0.384, p = 0.001) and lower attitudes and beliefs toward cancer (Gamma=-0.412, p = 0.001). Other demographic variables, such as family history, marital status, and occupation, were significantly related to patients’ attitudes toward and beliefs about cancer (Cramer’s V = 0.496, p < 0.001), whereas place of residence was strongly but non-significantly related (Cramer’s V = 0.96, p = 0.11).

Table 3.

Correlations between demographic characteristics and outcome variables (N = 468)

Variables	Insomnia	Quality of Life	Attitude and belief toward cancer
Nominal qualitative variables/dependent variables (rank qualitative); Cramer value (sig)
Family history	0.208 (< 0.001) *	0.48 (< 0.001) *	0.496 (< 0.001) *
Marital status	0.18 (< 0.001) *	0.23 (< 0.001) *	0.233 (< 0.001) *
Life status	0.213 (< 0.001) *	0.42 (< 0.001) *	0.37 (< 0.001) *
Job	0.199 (0.003) *	0.15 (0.001) *	0.2 (< 0.001) *
Place of residence	0.257 (< 0.001) *	0.27 (0.001) *	0.96 (0.11)
Rank qualitative variables/dependent variables (rank qualitative); Gama value (sig)
Age	0.184 (0.001) *	-0.146 (0.01) *	0.153 (0.02) *
Level of education	-0.05 (0.285)	-0.01(0.8)	-0.08 (0.168)
Duration of illness	-0.04 (0.47)	0.384 (0.001) *	-0.412 (0.001) *
Economic status	0.184 (0.016) *	-0.373 (0.001) *	0.04 (0.62)

Note. *p < 0.05

Predictor variables of quality of life, insomnia, attitude and belief

Table 4 summarizes the results of ordinal logistic regression models for predicting quality of life (QoL), insomnia, and patients’ attitudes and beliefs regarding cancer. Older age (OR = 1.02, p = 0.002), weak economic status (OR = 0.35, p = 0.024), urban residence in cities (OR = 1.62, p = 0.011), and living with parents (OR = 0.39, p = 0.046) were identified as significant predictors of insomnia. Quality of life was positively correlated with familial history (OR = 2.54, p < 0.001), weak (OR = 16.94, p < 0.001) and moderate (OR = 5.00, p = 0.001) economic status, and the status of being a wife residing alone (OR = 17.81, p < 0.001). However, it was negatively related to advanced age (OR = 0.97, p = 0.025) and urban living conditions (OR = 0.39, p < 0.001). Patients’ attitudes toward and beliefs about cancer were positively correlated with advanced age (OR = 1.03, p = 0.004), as were weak (OR = 4.05, p = 0.013) and moderate (OR = 5.25, p = 0.001) economic status. However, it was negatively correlated with familial history (OR = 0.23, p < 0.001) and marital status (OR = 0.10, p < 0.001). Notably, economic disadvantage had a disproportionately negative effect on quality of life (as evidenced by significantly higher odds ratios), whereas family history and marital/living circumstances had a significant effect on outcomes, emphasizing the importance of sociodemographic and contextual factors in patient well-being.

Table 4.

Predictor variables of quality of life, insomnia, attitude, and belief in women with breast cancer

Variable		Estimate	SE	Wald	df	Sig.	OR	95% CI
								Lower	Upper
Insomnia	Age	0.029	0.01	9.294	1	0.002	1.02	1.01	1.05
	Duration of illness	-0.025	0.045	0.32	1	0.571	0.975	0.89	1.06
	Family history (Yes)	-0.113	0.235	0.231	1	0.631	0.89	0.56	1.42
	Economic status (Weak)	-1.04	0.46	5.13	1	0.024	0.35	0.145	0.87
	Economic status (Moderate)	− 0.29	0.422	0.473	1	0.492	0.75	0.33	1.71
	Place of residence (Other cities)	0.485	0.192	6.417	1	0.011	1.62	1.11	3.9
	Life status (Wife)	− 0.267	0.432	0.382	1	0.537	0.765	0.33	1.78
	Life status (Wife and children)	0.064	0.473	0.018	1	0.893	1.07	0.43	2.7
	Life status (Parents)	-0.93	0.467	3.972	1	0.046	0.39	0.16	0.98
	Life status (Child)	0.722	0.517	1.952	1	0.162	2.06	0.75	5.7
Quality of life	Age	-0.029	0.013	5.03	1	0.025	0.97	0.95	0.99
	Duration of illness	− 0.007	0.059	0.015	1	0.932	0.99	0.88	1.11
	Family history (Yes)	0.943	0.262	13.15	1	< 0.001	2.54	1.54	4.26
	Economic status (Weak)	2.83	0.59	27.26	1	< 0.001	16.94	5.93	49.05
	Economic status (Moderate)	1.61	0.46	11.97	1	0.001	5	2.01	12.55
	Place of residence (Other cities)	-0.94	0.259	13.17	1	< 0.001	0.39	0.23	0.65
	Life status (Wife)	2.88	0.479	36.35	1	< 0.001	17.81	6.95	45.6
	Life status (Wife and children)	0.615	0.491	1.56	1	0.21	1.84	0.71	4.8
	Life status (Parents)	0.648	0.484	1.79	1	0.18	1.91	0.74	4.9
	Life status (Child)	0.814	0.538	2.28	1	0.13	2.25	0.78	6.42
Attitude and belief toward cancer and treatment	Age	0.035	0.012	8.23	1	0.004	1.03	1.01	1.06
	Duration of illness	-0.05	0.058	0.86	1	0.35	0.95	0.845	1.07
	Family history (Yes)	-1.43	0.265	29.13	1	< 0.001	0.23	0.14	0.4
	Economic status (Weak)	1.4	0.56	6.22	1	0.013	4.05	1.34	13.32
	Economic status (Moderate)	1.66	0.51	10.38	1	0.001	5.25	1.92	14.58
	Place of residence (Other cities)	-0.272	0.241	1.27	1	0.259	0.76	0.47	1.22
	Life status (Wife)	-2.24	0.472	22.56	1	< 0.001	0.1	0.04	0.26
	Life status (Wife and children)	-0.07	0.496	0.021	1	0.885	0.93	0.35	1.08
	Life status (Parents)	-0.89	0.498	3.21	1	0.073	0.41	0.15	1.09
	Life status (Child)	-0.39	0.545	0.53	1	0.466	0.67	0.23	1.95

*p < 0.05, SE = standard error; df = degree of freedom; OR = odds ratio; Economic status: Good as the baseline. Family history: No as the baseline. Place of Residence: Tehran as the baseline. Life status: Lonely as the baseline. Statistical test: Ordinal logistic regression

Discussion

The present study aimed to examine the relationships between quality of life, insomnia, attitudes and beliefs in women undergoing chemotherapy for breast cancer in selected hospitals of northern Iran. The results of this study revealed a statistically significant modest negative correlation between QoL and insomnia, a strong negative correlation between QoL with patients’ attitudes and beliefs related to cancer, and a positive correlation between patients’ attitudes and beliefs related to cancer and insomnia.

The findings which indicate that insomnia have a significant negative impact on quality of life was consistent with studies worldwide showing a connection between cancer patients decreased overall well-being and sleep difficulties [13, 14, 16]. The fact that approximately half of the participants had subclinical insomnia is noteworthy; nonetheless, even this type of sleep disturbance can exacerbate other mental distress, exhaustion, and increasing the physical consequences of chemotherapy [10, 14, 26]. Similarly, patients’ attitudes and beliefs toward breast cancer and quality of life have a substantial negative correlation, indicating that regional cultural beliefs regarding cancer as an immoral disease or mortality can worsen other psychological suffering and social isolation [24, 25]. This finding is in line with prior studies, where women’s psychological well-being is disproportionately affected by fatalistic perceptions, which are frequently heightened to promote negative thoughts towards cancer [24, 25]. These relationships are further clarified by the biopsychosocial Model, which views QoL as the result of interrelated biological, psychological, and social processes [8, 18]. Sleep patterns may be directly disturbed by the biological adverse effects of chemotherapy, such as fatigue and pain [27, 28]. Psychologically, patients’ attitudes and beliefs intensify emotional discomfort [24], while, socially, economic disparity limits access to supportive care [29, 30]. This structure is consistent with our findings that while longer disease duration and familial support enhanced QoL, whereas lower socioeconomic status and urban residency significantly impacted outcomes.

The study also revealed that several sociodemographic variables significantly influence quality of life and insomnia intensity. Economic inequality is an excellent indicator of exacerbated insomnia and a lower quality of life (QoL), confirming the basic relationship between financial stress and health outcomes. This finding aligns with prior studies that have shown that patients from lower socioeconomic backgrounds may encounter difficulties when trying to receive supportive care, which can exacerbate treatment-related challenges, and women with low socioeconomic status tend to participate less in breast cancer screening and treatment [29, 30]. Quality of life, insomnia and patients’ attitudes/beliefs toward cancer have been correlated with older age, most likely as a result of comorbidity, a lack of social support, or the internalization of age stereotypes [31, 32]. A lower quality of life is also correlated with urban living, which may be a result of urban pressures or disparities between rural and urban support networks [32]. Marital status and household composition have also been proven to have significant effects, as women who are single or socially isolated have lower outcomes, highlighting the protective function of social connectivity in collectivist culture [32]. In contrast, a longer duration of illness has been correlated with improved QoL, possibly due to adaptive processes, resilience, or skillful symptom management over time [28]. Similarly, a family history of cancer has been related to higher QoL, presumably due to enhanced health knowledge, early detection, or stronger support structures [28, 33].

This study has several strengths, including a robust sample size of 468 participants, the use of validated and reliable instruments (EORTC QLQ-C30, ISI, and Cancer Attitude and Belief Questionnaire), and culturally relevant insights into quality of life, belief, attitude and insomnia in Iranian women with breast cancer. The statistical analysis was thorough, and ethical standards were strictly followed. However, the study’s cross-sectional design limits causal inference. Convenience sampling from a single centre may restrict generalizability. Furthermore, reliance on self-reported data introduces potential bias, and certain confounding variables—such as comorbidities or chemotherapy intensity—were not controlled. Finally, the lack of information regarding last chemotherapy session which influence the studied variables limits understanding of participants’ associated factors.

The findings of this study have important clinical and research implications and highlights the need for routine screening of insomnia and negative cancer-related beliefs in women undergoing chemotherapy, as both significantly impact quality of life. Clinically, integrating brief, validated tools into care can help identify at-risk patients and guide timely interventions, such as cognitive-behavioral therapy for insomnia and culturally sensitive stigma-reduction strategies. Research-wise, the findings emphasize the influence of sociodemographic factors on patient well-being and point to the need for longitudinal and mixed-methods studies to better understand causal pathways and patient experiences. These insights can inform more effective, patient-centered care models in oncology.

Conclusion

This study highlights the intricate factors that impact the quality of life of patients with breast cancer undergoing chemotherapy, underscoring the need for all-encompassing, culturally sensitive healthcare interventions. Healthcare professionals and lawmakers can enhance survivorship results in northern Iran and similar situations around the world by addressing problems with insomnia, stereotypes, and inequality in socioeconomic status.

Author contributions

All the authors contributed significantly to this study in terms of conception, study design, execution, acquisition of data, analysis, and interpretation, or in all these areas. ZHM and MEJ: data collection, drafted the initial manuscript and were involved in data analysis. ZHM, and SKM: conceptualization, data collection, data analysis, revision of the subsequent manuscript, and supervision. AF, MHH, VP, RG and SHK: revised subsequent versions, data analysis and interpretation, visualization of the final manuscript, and final edits. All authors gave final approval of the version to be published, have agreed on the journal to which the article has been submitted and agree to be accountable for all aspects of the work. All the authors approved the final version.

Funding

The authors received no financial support for the research, authorship, or publication of this article.

Data availability

The datasets generated during and analyzed during the current study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Ethical approval was obtained from the Ethics Committee of Mazandaran University of Medical Sciences. (Approval number: IR.MUZUMS.IMAMHOSPITAL.REC.1401.13790). Informed consent to participate was obtained from all of the participants before participation in this study.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no conflicts of interest with respect to the research, authorship, and/or publication of this article.