Impact of Diabetes Mellitus on Complications and Outcomes of Adjuvant Chemotherapy in Older Patients With Breast Cancer

Purpose To evaluate whether diabetes affects patterns of adjuvant chemotherapy use, toxic effects of chemotherapy, and breast cancer outcomes. Patients and Methods By using the Surveillance, Epidemiology, and End Results–Medicare database, we identified patients aged 66 years or older who had stages I through III breast cancer that was diagnosed between 1992 and 2002. Multivariable regression analyses were performed to determine the effect of diabetes on use of chemotherapy, toxicities, and outcomes. The risks of all-cause mortality and breast cancer–specific (BCS) mortality were estimated with the Kaplan-Meier method. Results Our cohort had 70,781 men and women, of whom 14,414 (20.36%) had diabetes. Among people who received chemotherapy (n = 11,826), 21.0% were diabetics. In this group, diabetics had lower odds of receiving anthracyclines (odds ratio [OR], 0.78; 95% CI, 0.71 to 0.87) and taxanes (OR, 0.86; 95% CI, 0.75 to 0.99). Diabetes was associated with increased odds of being hospitalized for any c...