Impact of Racial/Ethnic Discrimination on Quality of Life Among Breast Cancer Survivors

Abstract

Although racial/ethnic disparities in health-care access, treatment, and cancer outcomes are well documented, the impact of racial/ethnic discrimination on cancer survivorship is unclear. We examined associations between quality of life (QoL) and self-reported discrimination among 3,991 women with breast cancer recruited during 2006–2013 from the Pathways Study in the Kaiser Permanente Northern California integrated health-care system, using linear regression models. Overall, 31% of women reported experiencing racial/ethnic discrimination, with differences by race/ethnicity (82% among non-Hispanic Black women vs. 19% among non-Hispanic White women) and nativity (40% among foreign-born Hispanic women vs. 76% among US-born Asian-American women). Experiencing racial/ethnic discrimination was associated with lower QoL in fully adjusted models. The mean QoL score was 119.6 (95% confidence interval (CI): 102.0, 137.1) for women who did not report discrimination, 115.5 (95% CI: 98.0, 133.0) for those who reported some discrimination/less than the median level, and 110.2 (95% CI: 92.7, 127.7) for those who reported more discrimination/greater than or equal to the median level. Discrimination was associated with lower QoL among women who used passive coping strategies or lived in neighborhoods with high neighborhood socioeconomic status, neighborhoods with high levels of segregation, or non–ethnic enclaves. Among breast cancer survivors, clinically meaningful differences in QoL scores were associated with racial/ethnic discrimination. Additional studies are needed to understand potential pathways through which these social factors affect survivorship outcomes.

Abbreviations

AAPI

Asian-American/Pacific Islander

CI

confidence interval

FACT-B

Functional Assessment of Cancer Therapy—Breast

NH

non-Hispanic

nSES

neighborhood socioeconomic status

QoL

quality of life

SES

socioeconomic status

Racial/ethnic disparities in access to health care, receipt of optimal medical treatment, and cancer outcomes are well documented (1). Racial/ethnic discrimination is a key social determinant of these health inequities, with intentional or unintentional differential treatment being based on racial/ethnic prejudices that occur between individuals or between individuals and institutions (2, 3). Discrimination has been shown to adversely affect both mental and physical health through multiple, complex pathways, including denial of goods and resources, psychosocial stress, and physical violence (2, 4).

Adverse health outcomes associated with self-reported experiences of racial/ethnic discrimination include higher mortality, less use of cancer screening, and poorer health-related quality of life (QoL) (5–9). QoL is an important prognostic factor for cancer survivors. Although racial/ethnic discrimination has been associated with poorer QoL in the general population (7–9), the impact of discrimination on QoL in cancer patients is largely unknown. Among the few studies conducted in cancer patients (10–12), including 1 study of breast cancer patients (10), experiences with racism or perceived mistreatment negatively influenced QoL, particularly among African-American cancer patients (10, 11). To address this literature gap, we assessed the association between self-reported experiences of racial/ethnic discrimination and QoL in the Pathways Study, a multiethnic cohort study of breast cancer survivors, and examined whether associations were moderated by individual coping strategies and neighborhood characteristics.

METHODS

The Pathways Study is a prospective cohort study of 4,505 racially and ethnically diverse women with incident breast cancer in the Kaiser Permanente Northern California integrated health-care system, recruited between 2006 and 2013. Most women reside in the San Francisco Bay Area (75%) and Sacramento (22%), California. Study recruitment has been previously described in detail (13). The study is overseen by local institutional review boards at collaborating institutions; informed consent was obtained from all study participants.

Interviewer and self-administered questionnaires were conducted within 2 months of diagnosis, on average, with information being collected on demographic characteristics, reproductive and family histories, lifestyle, and social factors at baseline and follow-up. Clinical data were also collected from Kaiser Permanente Northern California electronic data sources. Addresses at baseline were geocoded to 2010 geography; social and built attributes of each participant’s neighborhood were appended to participant records to derive a multilevel data set (14).

Self-reported experiences of racial/ethnic discrimination and coping strategy

The baseline survey assessed lifetime exposure to racial/ethnic discrimination using the previously validated “Experiences of Discrimination” measure (15), which assesses racial/ethnic discrimination across 8 domains, with medical care as an additional domain added to the scale. The Cronbach’s α value for the study sample was greater than 0.7 for discrimination subscales. Participants were asked, “Have you ever experienced discrimination, been prevented from doing something, or been hassled or made to feel inferior in any of the following situations because of your race/ethnicity or color?: at school; getting a job; at work; getting housing; getting medical care; getting service in a store/restaurant; getting credit/a loan/a mortgage; on the street/in a public setting; or from police/courts.” Frequency was ascertained if discrimination was reported in each of these situations, using the following categories: once, 2 or 3 times, or 4 or more times. A summary score of racial/ethnic discrimination experiences was calculated, where “no discrimination” responses were scored as 0, discrimination that occurred once was scored as 1, discrimination that occurred 2 or 3 times was scored as 2, and discrimination that occurred 4 or more times was scored as 3 (15). Responses across discrimination questions were averaged on the basis of the total number of items answered.

The participant’s general coping strategy was assessed prior to the discrimination assessment using 2 questions: “If you feel you have been treated unfairly, do you usually 1) accept it as a fact of life or 2) try to do something about it?” and “If you have been treated unfairly, do you usually 1) talk to other people about it or 2) keep it to yourself?” (15). Answers of 2 for the first question and 1 for the second question were categorized as “engaged,” while answers of 1 for the first question and 2 for the second question were categorized as “passive” (15). All other combinations were categorized as moderate.

Quality of life

The Functional Assessment of Cancer Therapy—Breast (FACT-B) is an extensively validated measure of QoL developed for breast cancer patients (16, 17). Briefly, a FACT-B QoL total score that assessed QoL within 7 days before baseline was calculated by summing participants’ scores on 5 individual subscales that included physical, social/family, emotional, and functional well-being, as well as breast-cancer–specific concerns. Cronbach’s α for the study sample was greater than 0.7 for all 5 QoL subscales.

Individual-level covariates

The baseline interview included data on the following plausible confounders: age, race/ethnicity, nativity (US-born vs. non–US-born), education, income, employment status, marital status, body mass index (weight (kg)/height (m)²), adult weight change since age 20 years, physical activity, smoking, alcohol consumption, and comorbidity (18). Data on breast cancer treatment and tumor characteristics were available from the Kaiser Permanente Northern California Cancer Registry and electronic health records. We created a combination variable to characterize the joint effects of race/ethnicity and nativity among Asian-American/Pacific Islander (AAPI) and Hispanic women in the cohort; we did not have a sufficient sample size to evaluate this intersection for non-Hispanic (NH) White and NH Black women, since 8.5% and 5.1% of NH White and NH Black women, respectively, were foreign-born. AAPI participants were predominantly of Chinese (37%), Filipina (37%), and Japanese (11%) ancestry; however, sample sizes were too small to use disaggregated data in our analyses. An indicator of individual socioeconomic status (SES) was derived by adding categories for the education and income variables (14). Specifically, education categories ranged from 1 to 4 (1 = high school; 2 = some college; 3 = college graduation; 4 = postgraduate study), and income categories ranged from 1 to 4 (1 = <$25,000/year; 2 = $25,000–$49,999/year; 3 = $50,000–$89,999/year; 4 = ≥$90,000/year). Possible values for the individual SES variable ranged from 2 (low) to 8 (high). Scores of 2 and 3 were combined because of low numbers.

Contextual factors

Racial/ethnic residential segregation refers to the racial/ethnic spatial distribution of residents across neighborhoods within a larger geographic area. This variable was operationalized using 2010 US Census data. The Dissimilarity Index measures the dimension of racial/ethnic evenness among residents of census tracts within a Metropolitan Statistical Area and the degree to which each census tract has the same distribution of a racial/ethnic minoritized group and NH White group relative to the overall metropolitan area (19). It ranges from 0 (no segregation) to 1 (complete segregation). For this study population, Dissimilarity Index measures of relative separation of NH Black, NH AAPI, and Hispanic residents as compared with NH White residents were considered, and the following cutpoints were applied: low = 0.00–0.30; moderate = 0.31–0.59; high = 0.60–1.00.

Ethnic enclaves are neighborhoods that are more ethnically distinct from other neighborhoods and are defined by a higher concentration of specific racial/ethnic populations, a higher concentration of immigrants, limited numbers of English-speaking residents, and linguistically isolated households. We derived enclave measures using principal components analyses with 2007–2011 American Community Survey data at the census tract level (20, 21). For Hispanics, we included data on linguistic isolation, English fluency, Spanish language use, Hispanic ethnicity, immigration history, and nativity, and for AAPIs, we included data on linguistic isolation, English fluency, AAPI language use, AAPI race/ethnicity, and immigration history. Hispanic and AAPI participants were assigned to their respective block group enclave statuses based on statewide quintiles.

The neighborhood racial/ethnic composition of block groups was assessed using a summary variable based on 2010 US Census data on the percentage of residents from each racial/ethnic group (14). We created variables indicating whether each block group was at/above or below the statewide median for AAPI, NH Black, and Hispanic populations and then combined these into a single variable categorizing block groups as being at/above state medians for all 3 groups, at/above the AAPI and NH Black state medians, at/above the AAPI state median, below state medians for all 3 groups, and other combinations.

Neighborhood socioeconomic status (nSES) was developed using a composite measure that incorporates census block group data on education, occupation, unemployment, household income, poverty, rent, and house values (14, 22). We categorized nSES into statewide quintiles.

Statistical analysis

The final analytical data set (n = 3,991) excluded women with missing data on racial/ethnic discrimination (n = 222) or QoL (n = 292). We operationalized racial/ethnic discrimination as both 2-level (any vs. none) and 3-level (none, low, or high) variables. For the 3-level variable, among women reporting discrimination experiences, we split participants on the median summary score (0.45), with those below the median score considered as reporting lower levels of discrimination and those at or above the median score as reporting higher levels of discrimination.

Associations were examined using both linear (continuous QoL score) and logistic (binary QoL/better vs. worse (at/above the sample median score of 125 or below the sample median)) (23) regression models. We estimated associations using a model that minimally adjusted for age and American Joint Committee on Cancer tumor stage and a model that additionally adjusted for confounders associated with both discrimination and QoL (race/ethnicity and nativity, individual SES, employment status, marital status, nSES, neighborhood racial/ethnic composition, body mass index, percentage of adult weight change, smoking, Charlson Comorbidity Index score, and tumor stage) and covariates associated with discrimination only (number of full-term pregnancies and nonsedentary physical activity). We examined interactions using cross-product terms between racial/ethnic discrimination and the following hypothesized modifiers: race/ethnicity, residential segregation (Dissimilarity Index), living in an AAPI or Hispanic enclave (among AAPI and Hispanic participants only), nSES, and coping strategy. For interaction analysis, ethnic enclave quintiles 1–3 (lower enclave status) and 4 and 5 (higher enclave status) were combined. Similarly, nSES was categorized into low nSES (quintiles 1–3) and high nSES (quintiles 4 and 5) for analysis. The following interactions with discrimination were statistically significant (P < 0.05); therefore, we present those results using stratified models: NH White/NH Black Dissimilarity Index among NH Black participants; living in a Hispanic enclave among Hispanic participants; nSES; and coping strategy.

Tests for trend were performed by entering the categorical variable as an ordinal-level parameter. Two-sided Wald statistic P values are reported for trend tests and tests of heterogeneity. Statistical significance was set at P < 0.05. Analyses were conducted using SAS, version 9.4 (SAS Institute, Inc., Cary, North Carolina).

RESULTS

Overall, 31% of women reported experiencing discrimination (Table 1); this varied from 82% of NH Black women to 19% of NH White women. While similar proportions of US-born and foreign-born Hispanic women reported discrimination (41% and 40%, respectively), among AAPI women, 76% of US-born and 49% of foreign-born women reported discrimination.

Table 1.

Distribution (%) of Self-Reported Experiences of Racial/Ethnic Discrimination by Race/Ethnicity and Nativity Among Breast Cancer Survivors in the Pathways Study, 2005–2013

	Race/Ethnicity and Nativity							Total   (n = 3,991)
	Non-Hispanic		Hispanic		Asian-American/Pacific Islander		American Indian/ Alaska Native   (n = 102)
Racial/Ethnic   Discrimination Status,   Score, and Setting	White   (n = 2,593)	Black   (n = 308)	Foreign-Born   (n = 205)	US-Born   (n = 280)	Foreign-Born   (n = 369)	US-Born   (n = 134)
Discrimination
None	81	18	60	59	51	24	73	69
Any	19	82	40	41	49	76	27	31
Discrimination scorea,b
Low	62	21	54	48	46	34	54	48
High	38	79	46	52	54	66	46	52
Discrimination settinga
At school	31	54	35	56	35	58	43	41
Getting a job	32	53	35	27	33	26	25	35
At work	43	62	56	43	51	35	43	48
Getting housing	8	32	7	14	10	17	21	15
Getting medical care	5	12	9	5	10	2	7	7
Getting service	27	77	38	41	51	63	29	46
Getting credit	11	33	10	8	11	5	21	15
In a public setting	33	58	37	41	46	64	43	43
From police/in court	7	28	17	17	13	6	14	14

^a Among those experiencing any racial/ethnic discrimination.

^b Low = less than median racial/ethnic discrimination score (<0.45); high = median score or higher (≥0.45).

QoL scores ranged from 34.0 to 156.0 in the study population, with an interquartile range of 110.0–136.3 and a median value of 125.

Compared with participants who reported high QoL at baseline, those who reported low QoL were younger, more often identified as being from a racial/ethnic minoritized group, were more often employed, and more often had late-stage disease (see Web Table 1, available at https://doi.org/10.1093/aje/kwac208).

Women who reported any racial/ethnic discrimination had lower QoL in the minimally adjusted model (any: mean FACT-B score = 114.3 (95% confidence interval (CI): 112.8, 115.8); none: mean FACT-B score = 120.8 (95% CI: 119.5, 122.1)) (Table 2). This association persisted in fully adjusted models (any: mean FACT-B score = 113.2 (95% CI: 95.7, 130.7); none: mean FACT-B score = 119.6 (95% CI: 102.0, 137.1)). A dose-response relationship was observed, with increasing discrimination being associated with lower QoL (low: mean FACT-B score = 115.5 (95% CI: 98.0, 133.0); high: mean FACT-B score = 110.2 (95% CI: 92.7, 127.7)). For the dichotomous measure of low versus high QoL, the odds ratio for any discrimination versus none in the fully adjusted model was 1.83 (95% CI: 1.55, 2.15) (Web Table 2). Corresponding odds ratios were 2.28 (95% CI: 1.83, 2.84) for high versus no discrimination and 1.54 (95% CI: 1.26, 1.87) for low versus no discrimination. Patterns of associations between discrimination and each of the FACT-B subscores were equivalent and similar to patterns found for the overall FACT-B score (Web Table 3).

Table 2.

Association Between Racial/Ethnic Discrimination and Quality of Life Among Breast Cancer Survivors in the Pathways Study, 2005–2013

Racial/Ethnic   Discrimination Status   and Score	FACT-B QoL Score Status a ,   no. of participants		FACT-B QoL Score   (Model 1)b		P for Linear Trend	FACT-B QoL Score   (Model 2)c		P for   Linear Trend
	Low	High	Mean	95% CI		Mean	95% CI
Discrimination					<0.01			<0.01
None	1,214	1,524	120.8	119.5, 122.1		119.6	102.0, 137.1
Any	766	487	114.3	112.8, 115.8		113.2	95.7, 130.7
Discrimination scored					<0.01			<0.01
0	1,214	1,524	120.8	119.4, 122.1		119.5	102.0, 137.0
Low	338	258	116.5	114.6, 118.3		115.5	98.0, 133.0
High	428	229	112.2	110.4, 114.1		110.2	92.7, 127.7

Abbreviations: CI, confidence interval; FACT-B, Functional Assessment of Cancer Therapy—Breast; QoL, quality of life.

^a Low = less than median FACT-B QoL score (<125); high = median score or higher (≥125).

^b Model 1 adjusted for age and stage.

^c Model 2 adjusted for age, tumor stage, race/ethnicity and nativity, individual socioeconomic status, employment status, neighborhood socioeconomic status, neighborhood racial/ethnic composition, marital status, number of full-term pregnancies, smoking status, current body mass index, percent change in adult body weight, nonsedentary physical activity, and comorbidity.

^d Low = less than median racial/ethnic discrimination score (<0.45); high = median score higher (≥0.45).

Significant interactions were found in the linear regression models by coping strategy (Table 3) and nSES (Table 4). The lowest QoL scores when experiencing discrimination were observed among women who used passive coping strategies (any: mean FACT-B score = 90.5 (95% CI: 74.6, 106.3); none: mean FACT-B score = 107.9 (95% CI: 92.2, 123.6)). Compared with women who resided in areas of low nSES, women who resided in areas of high nSES had slightly lower QoL scores when experiencing discrimination (any: mean FACT-B score = 108.0 (95% CI: 95.0, 121.1); none: mean FACT-B score = 113.0 (95% CI: 100.0, 126.0)).

Table 3.

Effect Modification of the Association Between Racial/Ethnic Discrimination and Quality of Life by Coping Strategy Among Breast Cancer Survivors in the Pathways Study, 2005–2013

Racial/Ethnic   Discrimination Status   and Score	FACT-B QoL Score Status a ,   no. of participants		FACT-B QoL Score		P Value
	Low	High	Mean b	95% CI	P for   Linear Trend	P for   Heterogeneity
Passive coping
Discrimination					<0.01	0.01
None	79	71	107.9	92.2, 123.6
Any	65	16	90.5	74.6, 106.3
Discrimination scorec					<0.01	0.02
0	79	71	107.1	91.4, 122.9
Low	31	10	93.1	76.8, 109.3
High	34	6	85.6	68.4, 102.8
Moderate coping
Discrimination					<0.01
None	220	227	113.1	95.6, 130.6
Any	137	69	107.0	89.7, 124.4
Discrimination score					<0.01
0	220	227	112.7	95.23, 130.2
Low	63	39	108.6	91.1, 126.0
High	74	30	104.4	86.7, 122.1
Engaged coping
Discrimination					<0.01
None	902	1,214	116.6	104.1, 129.2
Any	556	399	111.0	98.4, 123.5
Discrimination score					<0.01
0	902	1,214	117.4	104.9, 129.9
Low	242	207	114.0	101.4, 126.6
High	314	192	108.8	96.2, 121.4

Abbreviations: CI, confidence interval; FACT-B, Functional Assessment of Cancer Therapy—Breast; QoL, quality of life.

^a Low = less than median FACT-B QoL score (<125); high = median score or higher (≥125).

^b Adjusted for age, tumor stage, race/ethnicity and nativity, individual socioeconomic status, employment status, neighborhood socioeconomic status, neighborhood racial/ethnic composition, marital status, number of full-term pregnancies, smoking status, current body mass index, percent change in adult body weight, nonsedentary physical activity, and comorbidity.

^c Low = less than median racial/ethnic discrimination score (<0.45); high median score or higher (≥0.45).

Table 4.

Effect Modification of the Association Between Racial/Ethnic Discrimination and Quality of Life by Neighborhood Attributes Among Breast Cancer Survivors in the Pathways Study, 2005–2013

Racial/Ethnic   Discrimination Status   and Score	FACT-B QoL Score Status a ,   no. of participants		FACT-B QoL Score		P Value
	Low	High	Mean b	95% CI	P for   Linear Trend	P for   Heterogeneity
All Participants c
Neighborhood SESd
Low neighborhood SES
Discrimination					<0.01	0.01
None	437	501	119.0	101.7, 136.3
Any	313	170	110.8	93.6, 128.0
Discrimination scoree					<0.01	0.04
0	437	501	118.4	101.2, 135.7
Low	131	78	112.0	94.7, 129.2
High	182	92	108.3	90.9, 125.6
High neighborhood SES
Discrimination					<0.01
None	750	962	113.0	100.0, 126.0
Any	427	295	108.0	95.0, 121.1
Discrimination scoree					<0.01
0	750	962	113.9	100.9, 126.9
Low	197	171	111.5	98.4, 124.6
High	230	124	105.6	92.6, 118.6
Non-Hispanic Black Women Only f
Non-Hispanic White/Black    Dissimilarity Indexg
Low/moderate Dissimilarity     Index score
Discrimination					0.04	0.02
None	7	15	134.0	112.8, 155.1
Any	55	57	121.0	104.7, 137.2
Discrimination scoree					0.05	0.01
0	7	15	135.8	114.5, 157.1
Low	7	18	127.7	108.6, 146.8
High	48	39	120.2	103.9, 136.4
High Dissimilarity Index score
Discrimination					0.59
None	18	15	121.1	102.6, 139.5
Any	80	51	118.6	100.7, 136.5
Discrimination scoree					0.83
0	18	15	121.2	102.6, 139.8
Low	17	10	119.8	100.1, 139.6
High	63	41	118.4	100.3, 136.4
Foreign-Born Hispanic Women Only h
Hispanic enclave statusi
Low Hispanic enclave statusg
Discrimination					0.03	0.01
None	59	30	113.6	87.5, 139.8
Any	44	11	103.7	77.2, 130.3
Discrimination scoree					0.09	0.01
0	59	30	113.6	87.4, 139.9
Low	25	7	103.7	76.5, 131.0
High	19	4	103.7	75.4, 131.9
High Hispanic enclave status
Discrimination					0.58
None	21	10	122.6	82.0, 163.2
Any	15	11	126.9	88.5, 165.3
Discrimination scoree					0.16
0	21	10	120.4	82.1, 158.8
Low	7	5	115.0	76.5, 153.4
High	8	6	137.2	99.3, 175.1

Abbreviations: CI, confidence interval; FACT-B, Functional Assessment of Cancer Therapy—Breast; QoL, quality of life; SES, socioeconomic status.

^a Low = less than median FACT-B QoL score (<125); high = median score or higher (≥125).

^b Adjusted for age, tumor stage, race/ethnicity and nativity, individual socioeconomic status, employment status, neighborhood racial/ethnic composition, marital status, number of full-term pregnancies, smoking status, current body mass index, percent change in adult body weight, nonsedentary physical activity, and comorbidity.

^c Excludes 136 women whose baseline addresses could not be geocoded.

^d Low = statewide quintiles 1–3; high = statewide quintiles 4 and 5.

^e Low = less than median racial/ethnic discrimination score (<0.45); high = median score or higher (≥0.45).

^f Excludes 10 non-Hispanic Black women whose baseline addresses could not be geocoded.

^g Based on Metropolitan Statistical Area. Low/moderate index = <0.60; high = ≥0.60.

^h Excludes 4 foreign-born Hispanic women whose baseline addresses could not be geocoded.

ⁱ Not adjusted for neighborhood racial/ethnic composition.

Residential segregation modified the discrimination-QoL association among NH Black women, and residence in an ethnic enclave was a modifier among foreign-born Hispanic women (Table 4). Among NH Black women, those who lived in highly segregated areas had slightly lower QoL when experiencing discrimination (mean FACT-B score = 118.6, 95% CI: 100.7, 136.5) than those who lived in low/moderately segregated areas (mean FACT-B score = 121.0, 95% CI: 104.7, 137.2). Among foreign-born Hispanic women, QoL with self-reported discrimination was lower in nonenclave neighborhoods (mean FACT-B score = 103.7, 95% CI: 77.2, 130.3) than in enclave neighborhoods (mean FACT-B score = 126.9, 95% CI: 88.5, 165.3). There was no statistically significant heterogeneity observed in associations between discrimination and QoL for race/ethnicity, Hispanic enclaves among US-born Hispanic participants, and AAPI enclaves (Web Table 4).

DISCUSSION

To our knowledge, this is the first study to date to have quantitatively examined the association between racial/ethnic discrimination and QoL in a racially/ethnically diverse cohort of breast cancer survivors. In this cohort, experiencing racial/ethnic discrimination was associated with lower QoL for any experience of discrimination versus none, and the associations were stronger as the frequency of discriminatory experiences increased. Additionally, discrimination was associated with lower QoL among those who used “passive” coping than among those with “engaged” coping strategies. Among Black and Hispanic women, discrimination was associated with lower QoL only for women who resided in less segregated metropolitan areas or less ethnically/culturally distinct neighborhoods, respectively.

Our findings demonstrate that breast cancer survivors from racial/ethnic minoritized groups report a higher prevalence of racial/ethnic discrimination, similar to findings for the general adult population in California (24). Experiences with discrimination did not vary by nativity among Hispanic women but did among AAPI women, with US-born women reporting a higher prevalence of discrimination. Foreign-born AAPI women are more likely to reside in ethnic enclaves and therefore are less likely to interact with other racial/ethnic groups, reducing their exposure to discrimination (25). When we examined the locations where discrimination experiences occurred, higher proportions of NH Black women reported discrimination across all settings, except at school and in a public setting. Conversely, discrimination experiences at school and in public settings were reported more frequently by US-born AAPI women. More US-born than foreign-born women reported experiencing discrimination while at school, getting housing, getting service, and in a public setting. Among Hispanic women, more foreign-born than US-born women reported experiencing discrimination while interacting with police or in court. Regardless of the setting of racial/ethnic discrimination, we observed that discrimination experiences negatively affected QoL across groups.

Our findings are consistent with the literature on the adverse health effects of self-reported racial/ethnic discrimination. Only 1 previous study (to our knowledge) examined racial/ethnic discrimination and QoL in breast cancer survivors; that qualitative assessment found that women who experienced discrimination had more QoL concerns (10). There have been several qualitative studies in ethnically diverse noncancer populations analyzing the association between racial/ethnic discrimination and health status, quality of health care, and health-related behaviors, such as delay of medication or medical care (26–30). In one study, investigators found that perceived discrimination while seeking health care was highest among NH Black participants, intermediate for Hispanic participants, and lowest for NH White participants (26), as we found in our study. Overall, those who experienced discrimination were at 70% greater risk of poor health status, with equivalent risks for NH Black and NH White participants and no association in Hispanic participants (26). Another national study that included AAPI participants also found higher perceived discrimination in the health-care setting among racial/ethnic minoritized groups than among NH White participants, resulting in worse health status and lower health-care utilization (27). One small study in Asian Indians found that those who lived for more than 10 years in the United States and had chronic illnesses were more likely to perceive discrimination when seeking health care (28). However, Asian Indians at or over the age of 55 years were less likely to perceive discrimination than those aged 18–34 years (28). Finally, a recent study of nearly 40,000 participants in California found that those with Medicaid insurance were 66% more likely to experience discrimination than those with employer-sponsored health insurance coverage, although race/ethnicity did not modify the impact of discrimination (29). Furthermore, discrimination was associated with higher odds of delaying or forgoing both prescription medications and medical care (29).

Racial/ethnic discrimination has been hypothesized to influence QoL through multiple pathways, including psychological and physical pathways of stress, which can cause adverse health effects. Chronic stress from discrimination can lead to worse breast cancer morbidity and higher mortality among survivors (31). Chae et al. (32) explored telomere length as a biologically plausible factor through which racial/ethnic discrimination, mediated by stress, could affect health. Shorter telomere length is a marker of cellular aging, and stress has been associated with premature cell death and disease. However, in a pilot study carried out among 58 breast cancer patients, higher discrimination was not related to shorter telomere length (33). Allostatic load is another physiological manifestation of stress that may play a role in the relationship between racial/ethnic discrimination and QoL. Using national US data, allostatic load measured as a combination of cardiovascular, metabolic, and inflammatory biomarkers varied by race/ethnicity, with NH Black women having the highest loads (34). Studies that have evaluated discrimination and allostatic load in NH Black women, though not limited to cancer survivors, have produced conflicting evidence, with some finding a positive association (35) and others an inverse association (36, 37).

We observed statistically significant associations between discrimination and QoL among NH Black women in less segregated metropolitan areas and foreign-born Hispanic women in low-enclave neighborhoods. Women who reside in segregated areas or ethnic enclave neighborhoods may have more co–racial/ethnic support from neighbors and access to culturally and linguistically relevant resources to counter the impact of discrimination (38, 39). Similarly, women residing in higher-SES neighborhoods may have access to supportive resources or may face fewer stressors than women residing in lower-SES neighborhoods (40), which may explain the more modest discrimination-QoL associations in high-SES neighborhoods. Social support has been shown to buffer the impact of discrimination on health (41). While a prior study using different measures of discrimination and coping in African-American and White survivors of breast, prostate, lung, and colorectal cancers and non-Hodgkin lymphoma found that coping mediated mistreatment-QoL associations (11), we found coping to moderate this association, probably because of differences in measures and study populations.

Strengths of this study include a diverse study population of NH White, NH Black, AAPI, and Hispanic participants; analysis by place of birth; and comprehensive information on demographic factors, breast cancer risk factors, and neighborhood-level contextual factors. However, there were some limitations to the analysis. While we assessed cumulative lifetime discrimination experiences, our assessment did not allow us to distinguish timing of discrimination experiences in relation to QoL. While self-reported measures may be vulnerable to reporting bias, both perceived discrimination and FACT-B QoL score were measured using instruments that have been thoroughly validated (15, 17). While mean FACT-B scores were higher in our study sample than in previous FACT-B studies of breast cancer survivors (17, 42, 43), when we considered only those subscales that make up the Functional Assessment of Cancer Treatment Questionnaire—General (FACT-G) score, our sample was comparable to that in a prior study of women with and without breast cancer (44). Furthermore, our study population was specific to Northern California, and thus results may not be generalizable to all of California or the entire United States, especially since perceptions of and/or frequency of racism may differ by area; however, previous studies conducted in other states have seen similarly strong connections between discrimination and adverse health status (2, 4).

In conclusion, we found that self-reported racial/ethnic discrimination is associated with poorer QoL among breast cancer survivors in the Kaiser Permanente Northern California health-care system. Coping strategies and neighborhood factors moderated this association, with experiences of discrimination being more strongly associated with lower QoL among women with passive rather than active coping strategies and among those living in higher-SES rather than lower-SES neighborhoods. Further research is needed to understand potential pathways through which the impact of racial/ethnic discrimination on psychosocial factors affects survivorship outcomes.