Type 2 Diabetes and Breast Cancer Subtype in African American Women
African American women with type 2 diabetes are at an increased risk of developing estrogen receptor–negative breast cancer, according to a study by Julie R. Palmer, ScD, Associate Director of Boston University’s Slone Epidemiology Center, and colleagues, published in Cancer Research. However, there did not appear to be an association between type 2 diabetes and the incidence of estrogen receptor–positive breast cancer. Further biologic studies are needed to shed more light on the connections between diabetes and cancer.
The study looked at the relation of type 2 diabetes to the incidence of estrogen receptor–negative and estrogen receptor–positive breast cancer in data from the Black Women’s Health Study. The Black Women’s Health Study collected data on 59,000 African American women in the United States between the ages of 21 and 69 years over the course of 20 years.
Among African American women with a low body mass index (< 30 kg/m2), Dr. Palmer and colleagues saw a connection between women with type 2 diabetes and estrogen receptor–negative breast cancer. In addition, type 2 diabetes appeared to be associated with a 92% increased risk for estrogen receptor–negative breast cancer among non-obese women. The investigators concluded that poor metabolic function may play more of a role than obesity for this breast cancer subtype.