Kyung Na Lee1, Mylin A Torres2,3, Alyssa N Troeschel1, Jiabei He2,3, Keerthi Gogineni3,4, Lauren E McCullough1,3. 1. Department of Epidemiology, Emory University, Atlanta, Georgia, United States of America. 2. Department of Radiation Oncology, Emory University, Atlanta, Georgia, United States of America. 3. Glenn Family Breast Center of the Winship Cancer Institute, Emory University, Atlanta, Georgia, United States of America. 4. Department of Medical Oncology, Emory University, Atlanta, Georgia, United States of America.
Abstract
INTRODUCTION: While type 2 diabetes (T2D) has been associated with increased all-cause mortality among women diagnosed with breast cancer (BC), the association between T2D and breast cancer-specific (BCS) mortality is unresolved. The goal of this study was to examine the association between T2D and BCS mortality and examine the influence of metformin treatment on mortality rates. METHODS: A retrospective cohort study was conducted between 2002 and 2008 at Emory University Hospitals among non-Hispanic black and white women who had confirmed diagnosis of stage I-III BC and known diabetes status (T2D: n = 73; non-T2D: n = 514). Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: Compared to non-T2D patients, T2D women had almost a 2-fold increase in BCS mortality after adjusting for covariates (HR = 2.01; 95%CI = 1.02-3.98). Though attenuated, the increased hazard of death was also observed for all-cause mortality (HR = 1.74; 95%CI = 1.06-2.87). T2D patients who were not on metformin had substantially higher hazard of BCS mortality compared to non-diabetic patients (HR = 4.54; 95%CI = 1.98-10.44), whereas the association among T2D patients treated with metformin was weak (HR = 1.20; 95%CI = 0.36-3.97) and included the null. CONCLUSIONS: Among women with BC, T2D is associated with increased BCS mortality. Metformin treatment for T2D during the initial diagnosis of BC may improve outcomes.
INTRODUCTION: While type 2 diabetes (T2D) has been associated with increased all-cause mortality among women diagnosed with breast cancer (BC), the association between T2D and breast cancer-specific (BCS) mortality is unresolved. The goal of this study was to examine the association between T2D and BCS mortality and examine the influence of metformin treatment on mortality rates. METHODS: A retrospective cohort study was conducted between 2002 and 2008 at Emory University Hospitals among non-Hispanic black and white women who had confirmed diagnosis of stage I-III BC and known diabetes status (T2D: n = 73; non-T2D: n = 514). Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: Compared to non-T2D patients, T2D women had almost a 2-fold increase in BCS mortality after adjusting for covariates (HR = 2.01; 95%CI = 1.02-3.98). Though attenuated, the increased hazard of death was also observed for all-cause mortality (HR = 1.74; 95%CI = 1.06-2.87). T2D patients who were not on metformin had substantially higher hazard of BCS mortality compared to non-diabeticpatients (HR = 4.54; 95%CI = 1.98-10.44), whereas the association among T2D patients treated with metformin was weak (HR = 1.20; 95%CI = 0.36-3.97) and included the null. CONCLUSIONS: Among women with BC, T2D is associated with increased BCS mortality. Metformin treatment for T2D during the initial diagnosis of BC may improve outcomes.
Authors: Jamie Hartmann-Boyce; Karen Rees; James C Perring; Sven A Kerneis; Elizabeth M Morris; Clare Goyder; Afolarin A Otunla; Olivia A James; Nandana R Syam; Samuel Seidu; Kamlesh Khunti Journal: Diabetes Care Date: 2021-10-28 Impact factor: 17.152