Diabetes and Other Comorbidities in Breast Cancer Survival by Race/Ethnicity: The California Breast Cancer Survivorship Consortium (CBCSC). Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology Wu, A. H., Kurian, A. W., Kwan, M. L., John, E. M., Lu, Y., Keegan, T. H., Gomez, S. L., Cheng, I., Shariff-Marco, S., Caan, B. J., Lee, V. S., Sullivan-Halley, J., Tseng, C., Bernstein, L., Sposto, R., Vigen, C. 2015; 24 (2): 361-368


Background:The role of comorbidities in survival of breast cancer patients has not been well studied, particularly in non-white populations. Methods: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 hazards ratios (HR) and 95% confidence intervals (CI) for overall and breast cancer-specific mortality associated with previous cancer, diabetes, high blood pressure (HBP), and myocardial infarction (MI). Results: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 MI (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 radiation 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 MI by radiation and chemotherapy (P interaction=0.09). Conclusion:These results may inform future treatment guidelines for breast cancer patients with a history of diabetes or MI. Impact:Given the growing number of breast cancer survivors worldwide, we need to better understand how comorbidities may adversely affect treatment decisions and ultimately outcome.

View details for DOI 10.1158/1055-9965.EPI-14-1140

View details for PubMedID 25425578