California Breast Cancer Survivorship Consortium Research Articles

Hospital Characteristics and Breast Cancer Survival in the California Breast Cancer Survivorship Consortium.

Racial/ethnic disparities in breast cancer survival are well documented, but the influence of health care institutions is unclear. We therefore examined the effect of hospital characteristics on survival. Harmonized data pooled from 5 case-control and prospective cohort studies within the California Breast Cancer Survivorship Consortium were linked to the California Cancer Registry and the California Neighborhoods Data System. The study included 9,701 patients with breast cancer who were diagnosed between 1993 and 2007. First reporting hospitals were classified by hospital type-National Cancer Institute (NCI) -designated cancer center, American College of Surgeons (ACS) Cancer Program, other-and hospital composition of the neighborhood socioeconomic status and race/ethnicity of patients with cancer. Multivariable Cox proportional hazards models adjusted for clinical and patient-level prognostic factors were used to examine the influence of hospital characteristics on survival. Fewer than one half of women received their initial care at an NCI-designated cancer center (5%) or ACS program (38%) hospital. Receipt of initial care in ACS program hospitals varied by race/ethnicity-highest among non-Latina White patients (45%), and lowest among African Americans (21%). African-American women had superior breast cancer survival when receiving initial care in ACS hospitals versus other hospitals (non-ACS program and non-NCI-designated cancer center; hazard ratio, 0.67; 95% CI, 0.55 to 0.83). Other hospital characteristics were not associated with survival. African American women may benefit significantly from breast cancer care in ACS program hospitals; however, most did not receive initial care at such facilities. Future research should identify the aspects of ACS program hospitals that are associated with higher survival and evaluate strategies by which to enhance access to and use of high-quality hospitals, particularly among African American women.

Abstract IA42: Multiethnic differences in BMI, body composition, and survival in colorectal and breast cancer

Abstract Rationale: The disproportionate burden of obesity among minority populations is hypothesized to contribute to racial/ethnic disparities in cancer mortality rates (1). However, several studies note differences by race/ethnicity in the relationship of higher BMI to cancer survival, with the strongest adverse associations often seen among non-Hispanic white patients and the weakest among black patients (2-6). A potential explanation is that BMI is an imperfect proxy for total adiposity that does not distinguish muscle from fat mass. Further, data from noncancer patients suggests that body composition at a given BMI may vary by race/ethnicity, underscoring the need for more accurate measures of fat and lean mass to understand the contribution of the body habitus to disparities in cancer survival. Methods: We will summarize the existing literature and present new data on: (1) differences in the BMI-mortality relationship by race/ethnicity, (2) differences in body composition by race/ethnicity, and (3) associations of body composition with mortality among survivors of breast and colorectal cancer by race/ethnicity. For brevity, we will focus on black-white differences in overall survival from a cohort of ~5,000 nonmetastatic breast or colorectal cancer patients at Kaiser Permanente Northern California. Body composition was quantified using clinically-acquired computed tomography (CT) scans, a gold standard to assess adiposity and muscle mass. Results: Body composition at a given BMI differs by race/ethnicity in the general population and among cancer survivors. Among 234 black and 2,290 white breast cancer patients, BMI was not associated with survival. By contrast, higher total adiposity and lower skeletal muscle were both associated with increased risk of death after breast cancer: the HR (95% CI) comparing the highest (versus lowest) tertile of total adiposity index was 2.43 (1.20, 4.92) among black and 1.48 (1.13, 1.93) among white women, respectively, and the HR comparing the lowest (versus highest) tertile of skeletal muscle index was 1.67 (0.82, 3.41) among black and 1.37 (1.05, 1.80) among white women, respectively. Among 243 black and 2,192 white colorectal cancer patients, BMI was associated with survival only among white patients (overweight was associated with a 22% reduction in mortality). By contrast, higher visceral adiposity and lower skeletal muscle were associated with increased risk of death after colorectal cancer diagnosis in both groups: the HR (95% CI) comparing the highest (versus lowest) tertile of visceral adiposity index was 2.64 (1.39, 4.99) among black patients and 1.35 (1.07, 1.70) among white patients, respectively, and the HR comparing the lowest (versus highest) tertile of skeletal muscle index was 2.13 (1.17, 3.88) among black and 1.71 (1.39, 2.12) among white patients, respectively. Conclusion: Body composition assessed via CT scans produces measures of adiposity and muscle that associate with survival across racial/ethnic groups where BMI does not. Accurate assessment of body composition is critical for equitable prognostic assessments and for making appropriate lifestyle recommendations to diverse groups of survivors (e.g., recommending weight loss through caloric restriction only when beneficial and offering complementary interventions, such as building muscle mass through resistance training or physical activity, when appropriate).

The Effect of Patient and Contextual Characteristics on Racial/Ethnic Disparity in Breast Cancer Mortality.

Racial/ethnic disparity in breast cancer-specific mortality in the United States is well documented. We examined whether accounting for racial/ethnic differences in the prevalence of clinical, patient, and lifestyle and contextual factors that are associated with breast cancer-specific mortality can explain this disparity. The California Breast Cancer Survivorship Consortium combined interview data from six California-based breast cancer studies with cancer registry data to create a large, racially diverse cohort of women with primary invasive breast cancer. We examined the contribution of variables in a previously reported Cox regression baseline model plus additional contextual, physical activity, body size, and comorbidity variables to the racial/ethnic disparity in breast cancer-specific mortality. The cohort comprised 12,098 women. Fifty-four percent were non-Latina Whites, 17% African Americans, 17% Latinas, and 12% Asian Americans. In a model adjusting only for age and study, breast cancer-specific HRs relative to Whites were 1.69 (95% CI, 1.46-1.96), 1.00 (0.84-1.19), and 0.52 (0.33-0.85) for African Americans, Latinas, and Asian Americans, respectively. Adjusting for baseline-model variables decreased disparity primarily by reducing the HR for African Americans to 1.13 (0.96-1.33). The most influential variables were related to disease characteristics, neighborhood socioeconomic status, and smoking status at diagnosis. Other variables had negligible impact on disparity. Although contextual, physical activity, body size, and comorbidity variables may influence breast cancer-specific mortality, they do not explain racial/ethnic mortality disparity. Other factors besides those investigated here may explain the existing racial/ethnic disparity in mortality. Cancer Epidemiol Biomarkers Prev; 25(7); 1064-72. ©2016 AACR.

Validation of self-reported comorbidity status of breast cancer patients with medical records: the California Breast Cancer Survivorship Consortium (CBCSC).

To compare information from self-report and electronic medical records for four common comorbidities (diabetes, hypertension, myocardial infarction, and other heart diseases). We pooled data from two multiethnic studies (one case-control and one survivor cohort) enrolling 1,936 women diagnosed with breast cancer, who were members of Kaiser Permanente Northern California. Concordance varied by comorbidity; kappa values ranged from 0.50 for other heart diseases to 0.87 for diabetes. Sensitivities for comorbidities from self-report versus medical record were similar for racial/ethnic minorities and non-Hispanic Whites, and did not vary by age, neighborhood socioeconomic status, or education. Women with a longer history of comorbidity or who took medications for the comorbidity were more likely to report the condition. Hazard ratios for all-cause mortality were not consistently affected by source of comorbidity information; the hazard ratio was lower for diabetes, but higher for the other comorbidities when medical record versus self-report was used. Model fit was better when the medical record versus self-reported data were used. Comorbidities are increasingly recognized to influence the survival of patients with breast or other cancers. Potential effects of misclassification of comorbidity status should be considered in the interpretation of research results.

Abstract A67: Do hospital characteristics explain racial/ethnic disparities in mortality after breast cancer diagnosis: The California Breast Cancer Survivorship Consortium

Abstract Introduction: Disparities in breast cancer mortality persist between racial/ethnic groups. Little is known about the role of the treatment environment, specifically the characteristics of the hospital reporting a patient's breast cancer diagnosis. Differential access to high quality care contributes to disparities in treatment and outcomes. The California Breast Cancer Survivorship Consortium (CBCSC) integrated data on patient demographics, behavioral and reproductive characteristics from patient interviews, and on tumor characteristics, treatment, and follow-up from the California Cancer Registry. This study leveraged the large size and racial/ethnic diversity to examine the extent to which hospital characteristics explain racial/ethnic disparities in mortality following breast cancer diagnosis. Methods: Using data from five of the six studies in the CBCSC, the study sample included 4,624 non-Latina whites, 1,849 Latinas, 1,832 African-Americans, and 1,333 Asian Americans diagnosed with Stage I-IV breast cancer between 1993 and 2007. We used study- and stage-stratified Cox regression models to assess the independent associations of hospital characteristics with mortality, and examined the change in racial/ethnic hazard ratios before and after adjustment for hospital characteristics. Hospital characteristics included composition measures based on the patients served by each hospital such as SES (percent of cancer patients from the highest quintile SES neighborhoods), race/ethnicity, and insurance type as well as NCI cancer center designation. Distance from patients' residences to hospitals was also examined. Patient sociodemographics include race/ethnicity, education, marital status, and neighborhood SES; behavioral and reproductive factors include smoking, alcohol consumption, obesity, exercise, family history of breast cancer, and parity; and clinical factors include tumor characteristics, treatment, and co-morbidities. Results: For all-cause mortality, patients seen in high SES hospitals had lower mortality rates than those seen in low SES hospitals (HR=0.87, 95% CI=0.75-0.99). The other hospital characteristics were not associated with all-cause mortality. Compared with non-Latina whites, we observed a higher mortality rate for African-Americans (HR=1.40, 95% CI=1.23-1.58), a lower mortality rate for Latinas (HR=0.89, 95% CI=0.78-1.01) and no statistically different rate for Asian Americans (HR=0.80, 95% CI=0.60-1.07). After adjusting for hospital characteristics, the higher mortality rate observed for African-Americans was slightly attenuated (HR=1.34, 95% CI= 1.18-1.51) whereas the lower mortality rate for Latinas became slightly stronger (HR=0.86, 95% CI=0.75-0.98). No statistically significant associations were observed for breast cancer-specific mortality. We also tested for interactions between race/ethnicity and hospital characteristics and found no statistically significant interactions. Conclusion: Hospital SES (as measured based on patient composition) is independently associated with all-cause mortality after a diagnosis of breast cancer, even after adjusting for a patient's educational level and neighborhood SES. However, adjusting for hospital characteristics accounted only slightly for the higher overall mortality rate among African-Americans and strengthened the lower mortality rate observed among Latinas. The fact that most breast cancer treatment occurs outside of hospitals may explain the lack of an observed association with disease-specific mortality; by contrast, hospital SES likely signifies a combination of factors (for example, the presence and severity of co-morbidities beyond what was measured, and access to effective care) that contribute to a gradient in all-cause mortality. Citation Format: Salma Shariff-Marco, Allison W. Kurian, Juan Yang, Jocelyn Koo, Esther M. John, Theresa H. M. Keegan, Iona Cheng, Kristine R. Monroe, Cheryl Vigen, Marilyn L. Kwan, Yani Lu, Brian E. Henderson, Leslie Bernstein, Richard Sposto, Anna H. Wu, Scarlett L. Gomez. Do hospital characteristics explain racial/ethnic disparities in mortality after breast cancer diagnosis: The California Breast Cancer Survivorship Consortium. [abstract]. In: Proceedings of the Seventh AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 9-12, 2014; San Antonio, TX. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2015;24(10 Suppl):Abstract nr A67.

Contribution of the neighborhood environment and obesity to breast cancer survival: the California Breast Cancer Survivorship Consortium.

Little is known about neighborhood attributes that may influence opportunities for healthy eating and physical activity in relation to breast cancer mortality. We used data from the California Breast Cancer Survivorship Consortium and the California Neighborhoods Data System (CNDS) to examine the neighborhood environment, body mass index, and mortality after breast cancer. We studied 8,995 African American, Asian American, Latina, and non-Latina white women with breast cancer. Residential addresses were linked to the CNDS to characterize neighborhoods. We used multinomial logistic regression to evaluate the associations between neighborhood factors and obesity and Cox proportional hazards regression to examine associations between neighborhood factors and mortality. For Latinas, obesity was associated with more neighborhood crowding [quartile 4 (Q4) vs. Q1: OR, 3.24; 95% confidence interval (CI), 1.50-7.00]; breast cancer-specific mortality was inversely associated with neighborhood businesses (Q4 vs. Q1: HR, 0.46; 95% CI, 0.25-0.85) and positively associated with multifamily housing (Q3 vs. Q1: HR, 1.98; 95% CI, 1.20-3.26). For non-Latina whites, lower neighborhood socioeconomic status (SES) was associated with obesity [quintile 1 (Q1) vs. Q5: OR, 2.52; 95% CI, 1.31-4.84], breast cancer-specific (Q1 vs. Q5: HR, 2.75; 95% CI, 1.47-5.12), and all-cause (Q1 vs. Q5: HR, 1.75; 95% CI, 1.17-2.62) mortality. For Asian Americans, no associations were seen. For African Americans, lower neighborhood SES was associated with lower mortality in a nonlinear fashion. Attributes of the neighborhood environment were associated with obesity and mortality following breast cancer diagnosis, but these associations differed across racial/ethnic groups.

Intersection of Race/Ethnicity and Socioeconomic Status in Mortality After Breast Cancer.

We investigated social disparities in breast cancer (BC) mortality, leveraging data from the California Breast Cancer Survivorship Consortium. The associations of race/ethnicity, education, and neighborhood SES (nSES) with all-cause and BC-specific mortality were assessed among 9372 women with BC (diagnosed 1993-2007 in California with follow-up through 2010) from four racial/ethnic groups [African American, Asian American, Latina, and non-Latina (NL) White] using Cox proportional hazards models. Compared to NL White women with high-education/high-nSES, higher all-cause mortality was observed among NL White women with high-education/low-nSES [hazard ratio (HR) (95 % confidence interval) 1.24 (1.08-1.43)], and African American women with low-nSES, regardless of education [high education HR 1.24 (1.03-1.49); low-education HR 1.19 (0.99-1.44)]. Latina women with low-education/high-nSES had lower all-cause mortality [HR 0.70 (0.54-0.90)] and non-significant lower mortality was observed for Asian American women, regardless of their education and nSES. Similar patterns were seen for BC-specific mortality. Individual- and neighborhood-level measures of SES interact with race/ethnicity to impact mortality after BC diagnosis. Considering the joint impacts of these social factors may offer insights to understanding inequalities by multiple social determinants of health.

History of Recreational Physical Activity and Survival After Breast Cancer: The California Breast Cancer Survivorship Consortium.

Recent epidemiologic evidence suggests that prediagnosis physical activity is associated with survival in women diagnosed with breast cancer. However, few data exist for racial/ethnic groups other than non-Latina whites. To examine the association between prediagnosis recreational physical activity and mortality by race/ethnicity, we pooled data from the California Breast Cancer Survivorship Consortium for 3 population-based case-control studies of breast cancer patients (n=4,608) diagnosed from 1994 to 2002 and followed up through 2010. Cox proportional hazards models provided estimates of the relative hazard ratio for mortality from all causes, breast cancer, and causes other than breast cancer associated with recent recreational physical activity (i.e., in the 10 years before diagnosis). Among 1,347 ascertained deaths, 826 (61%) were from breast cancer. Compared with women with the lowest level of recent recreational physical activity, those with the highest level had a marginally decreased risk of all-cause mortality (hazard ratio=0.88, 95% confidence interval: 0.76, 1.01) and a statistically significant decreased risk of mortality from causes other than breast cancer (hazard ratio=0.63, 95% confidence interval: 0.49, 0.80), and particularly from cardiovascular disease. No association was observed for breast cancer-specific mortality. These risk patterns did not differ by race/ethnicity (non-Latina white, African American, Latina, and Asian American). Our findings suggest that physical activity is beneficial for overall survival regardless of race/ethnicity.

Diabetes and other comorbidities in breast cancer survival by race/ethnicity: the California Breast Cancer Survivorship Consortium (CBCSC).

The role of comorbidities in survival of patients with breast cancer has not been well studied, particularly in non-white populations. We investigated the association of specific comorbidities with mortality in a multiethnic cohort of 8,952 breast cancer cases within the California Breast Cancer Survivorship Consortium (CBCSC), which pooled questionnaire and cancer registry data from five California-based studies. In total, 2,187 deaths (1,122 from breast cancer) were observed through December 31, 2010. Using multivariable Cox proportional hazards regression, we estimated HRs and 95% confidence intervals (CI) for overall and breast cancer-specific mortality associated with previous cancer, diabetes, high blood pressure (HBP), and myocardial infarction. Risk of breast cancer-specific mortality increased among breast cancer cases with a history of diabetes (HR, 1.48; 95% CI, 1.18-1.87) or myocardial infarction (HR, 1.94; 95% CI, 1.27-2.97). Risk patterns were similar across race/ethnicity (non-Latina white, Latina, African American, and Asian American), body size, menopausal status, and stage at diagnosis. In subgroup analyses, risk of breast cancer-specific mortality was significantly elevated among cases with diabetes who received neither radiotherapy nor chemotherapy (HR, 2.11; 95% CI, 1.32-3.36); no increased risk was observed among those who received both treatments (HR, 1.13; 95% CI, 0.70-1.84; P(interaction) = 0.03). A similar pattern was found for myocardial infarction by radiotherapy and chemotherapy (P(interaction) = 0.09). These results may inform future treatment guidelines for patients with breast cancer with a history of diabetes or myocardial infarction. Given the growing number of breast cancer survivors worldwide, we need to better understand how comorbidities may adversely affect treatment decisions and ultimately outcome.

Obesity and mortality after breast cancer by race/ethnicity: The California Breast Cancer Survivorship Consortium.

We investigated body size and survival by race/ethnicity in 11,351 breast cancer patients diagnosed from 1993 to 2007 with follow-up through 2009 by using data from questionnaires and the California Cancer Registry. We calculated hazard ratios and 95% confidence intervals from multivariable Cox proportional hazard model-estimated associations of body size (body mass index (BMI) (weight (kg)/height (m)(2)) and waist-hip ratio (WHR)) with breast cancer-specific and all-cause mortality. Among 2,744 ascertained deaths, 1,445 were related to breast cancer. Being underweight (BMI <18.5) was associated with increased risk of breast cancer mortality compared with being normal weight in non-Latina whites (hazard ratio (HR) = 1.91, 95% confidence interval (CI): 1.14, 3.20), whereas morbid obesity (BMI ≥ 40) was suggestive of increased risk (HR = 1.43, 95% CI: 0.84, 2.43). In Latinas, only the morbidly obese were at high risk of death (HR = 2.26, 95% CI: 1.23, 4.15). No BMI-mortality associations were apparent in African Americans and Asian Americans. High WHR (quartile 4 vs. quartile 1) was associated with breast cancer mortality in Asian Americans (HR = 2.21, 95% CI: 1.21, 4.03; P for trend = 0.01), whereas no associations were found in African Americans, Latinas, or non-Latina whites. For all-cause mortality, even stronger BMI and WHR associations were observed. The impact of obesity and body fat distribution on breast cancer patients' risk of death may vary across racial/ethnic groups.

The California Breast Cancer Survivorship Consortium (CBCSC): prognostic factors associated with racial/ethnic differences in breast cancer survival

Racial/ethnic disparities in mortality among US breast cancer patients are well documented. Our knowledge of the contribution of lifestyle factors to disease prognosis is based primarily on non-Latina Whites and is limited for Latina, African American, and Asian American women. To address this knowledge gap, the California Breast Cancer Survivorship Consortium (CBCSC) harmonized and pooled interview information (e.g., demographics, family history of breast cancer, parity, smoking, alcohol consumption) from six California-based breast cancer studies and assembled corresponding cancer registry data (clinical characteristics, mortality), resulting in 12,210 patients (6,501 non-Latina Whites, 2,060 African Americans, 2,032 Latinas, 1,505 Asian Americans, 112 other race/ethnicity) diagnosed with primary invasive breast cancer between 1993 and 2007. In total, 3,047 deaths (1,570 breast cancer specific) were observed with a mean (SD) follow-up of 8.3 (3.5) years. Cox proportional hazards regression models were fit to data to estimate hazards ratios (HRs) and 95 % confidence intervals (CIs) for overall and breast cancer-specific mortality. Compared with non-Latina Whites, the HR of breast cancer-specific mortality was 1.13 (95 % CI 0.97-1.33) for African Americans, 0.84 (95 % CI 0.70-1.00) for Latinas, and 0.60 (95 % CI 0.37-0.97) for Asian Americans after adjustment for age, tumor characteristics, and select lifestyle factors. The CBCSC represents a large and racially/ethnically diverse cohort of breast cancer patients from California. This cohort will enable analyses to jointly consider a variety of clinical, lifestyle, and contextual factors in attempting to explain the long-standing disparities in breast cancer outcomes.

Abstract A04: The California Breast Cancer Survivorship Consortium (CBCSC): Prognostic factors associated with racial/ethnic differences in breast cancer survival

Abstract Background: Racial/ethnic disparities in mortality among US breast cancer patients are well documented. Using 2000-2006 data from Surveillance, Epidemiology, and End Results (SEER) registries, relative risk [95% confidence interval (CI)] of breast cancer-specific mortality relative to non-Latina Whites was significantly higher for African Americans (1.5 [1.4,1.6]) and Latinas (1.1 [1.0,1.2]), and non-significantly lower (0.9 [0.8,1.0]) for Asian Americans after adjusting for diagnosis age, SEER registry, disease stage, estrogen/progesterone receptor (ER/PR) status, county level poverty/education index, and other factors (Breast Cancer Res Treat, 127:729–738). Reasons for these differences are not well-understood; individual lifestyle factors may explain these differences, but current knowledge of the role of lifestyle in disease prognosis is limited for African Americans, Latinas and Asian Americans. Methods: The CBCSC assembled interview and cancer registry data from six California-based breast cancer etiology or prognosis studies, resulting in 12,210 breast cancer patients diagnosed with primary invasive breast cancer (6501 non-Latina Whites, 2060 African Americans, 2032 Latinas, 1505 Asian Americans, 112 others) between 1993 and 2007. Clinical characteristics and mortality data were obtained from the California Cancer Registry (CCR). Demographics (education, birthplace, migration), family history of breast cancer, parity, smoking, alcohol consumption, and other interview data were harmonized and pooled. Cox proportional hazards regression of overall and breast-cancer specific mortality were used to estimate racial/ethnic differences in stage-specific survival. Results: Frequency of adverse tumor characteristics (stage, differentiation, ER/PR status, nodal status, tumor size) were highest in African Americans, followed by Latinas, Asian Americans and non-Latina Whites, generally in that order. Latinas had lower education and higher parity than other racial/ethnic groups, whereas family history of breast cancer and alcohol consumption were highest in non-Latina Whites, and smoking was highest in African Americans. In total, 3047 deaths (1570 breast cancer-related) were observed after a mean (SD) follow-up of 8.3 (3.5) years. Compared to non-Latina Whites, the hazard ratio (HR) and 95% CI for breast cancer specific mortality was 1.15 [0.98,1.34] for African Americans, 0.77 [0.64,0.92], for Latinas, and 0.57 [0.36,0.92], for Asian Americans (adjusting for age and characteristics available from the tumor registry). HRs were slightly attenuated by further adjustment for education, migration, smoking and other factors (1.12 [0.95,1.31], 0.84 [0.69,1.02], 0.61 [0.38,0.99], respectively). Analyses are ongoing to determine the effect of neighborhood contextual factors, physical activity, body size, and comorbidities on racial/ethnic disparities in breast cancer survival. Conclusions: The CBCSC is a unique resource of a large and racially/ethnically diverse breast cancer cohort that will allow joint consideration of a variety of clinical, lifestyle, and contextual factors in explaining the long-standing disparities in breast cancer survival. Funded by: California Breast Cancer Research Program Special Research Initiative (16ZB-8004). Citation Format: Cheryl LP Vigen, Scarlett Lin Gomez, Richard Sposto, Yani Lu, Marilyn L. Kwan, Esther M. John, Kristine R. Monroe, Theresa HM Keegan, Salma Shariff-Marco, Allison W. Kurian, Iona Cheng, Bette J. Caan, Valerie S. Lee, Janise M. Roh, Jane Sullivan-Halley, Leslie Bernstein, Anna H. Wu. The California Breast Cancer Survivorship Consortium (CBCSC): Prognostic factors associated with racial/ethnic differences in breast cancer survival. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr A04.

Abstract A40: Body size and racial/ethnic differences in breast cancer survival.

Abstract Background: Studies of body size and breast cancer prognosis have primarily been conducted in non-Latina White women with little research to date in racial/ethnic minority groups. We investigated body size (body mass index [BMI], waist-hip-ratio [WHR], waist-height-ratio [WHtR], waist circumference [WC]) and survival by race/ethnicity (non-Latina White, African American, Asian American, and Latina) in the California Breast Cancer Survivorship Consortium (CBCSC). Methods: The CBCSC represents 12,025 breast cancer patients diagnosed with primary invasive breast cancer from 1993-2007 from six California-based studies of breast cancer etiology or prognosis. Data on body size, race/ethnicity, and relevant covariates previously collected from in-person interview or mailed questionnaire were harmonized and pooled. Clinical characteristics and mortality information were obtained from the California Cancer Registry. Body size measures included minimum 6 months pre-diagnosis BMI in kg/m2 (underweight &amp;lt;18.5, normal 18.5-&amp;lt;25, overweight 25-&amp;lt;30, obese 30-&amp;lt;35, severely obese 35-&amp;lt;40, morbidly obese ≥40), and median 1 year post-diagnosis WHR, WHtR, and WC (quartiles). Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the associations of each body size measure with all-cause and breast cancer-specific (BC) mortality, adjusted for sociodemographic, lifestyle, clinical, and treatment covariates. Results: Among 11,351 women with BMI data (6,044 non-Latina Whites, 1,886 African Americans, 1,451 Asian Americans, 1,864 Latinas, and 106 others), a total of 2,744 deaths (1,445 BC-related) were observed after a mean (SD) follow-up of 11.0 (3.8) years. Underweight and morbidly obese women had a statistically significant increased risk of overall mortality compared to normal-weight women (underweight HR=1.47; 95% CI: 1.13, 1.90 and morbidly obese HR=1.43; 95% CI: 1.16, 1.77; p for trend=0.012; departure from linearity p=0.005) while obese and severely obese women had borderline significant increased risks. Similar yet attenuated associations were found for BC mortality. Women in the highest WHR quartile compared to those in the lowest quartile had a significant increased risk of both overall death (HR=1.30; 95% CI: 1.10, 1.55) and BC death (HR=1.36; 95% CI: 1.07, 1.73) with a positive trend of larger WHR and increasing risk (p for trend&amp;lt;0.05). WHtR and WC had similar associations with mortality as WHR. Compared to the entire cohort, non-Latina Whites had an analogous U-shaped association of BMI with mortality risk, while African Americans and Asian Americans had no associations at any BMI level. Latinas had elevated risks only among the morbidly obese. In contrast, larger WHR was associated with mortality in African Americans (p for trend&amp;lt;0.001) while no associations with WHR were found in non-Latina Whites. Asian Americans had elevated risks only in the top WHR quartile. WHtR and WC were not associated with mortality in any race/ethnicity group. Conclusion: In this large, multiethnic study of breast cancer patients, we found that those with extreme BMI and increased WHR had the worse survival but that the associations varied by race/ethnicity. Obesity and body fat distribution around breast cancer diagnosis appear to have differential effects on survival depending on race/ethnicity. Funded by the California Breast Cancer Research Program Citation Format: Marilyn L. Kwan, Bette J. Caan, Valerie S. Lee, Esther M. John, Scarlett Lin Gomez, Salma Shariff-Marco, Theresa H. Keegan, Allison W. Kurian, Leslie Bernstein, Yani Lu, Iona Cheng, Kristine R. Monroe, Richard Sposto, Cheryl Vigen, Anna H. Wu. Body size and racial/ethnic differences in breast cancer survival. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr A40.