Mortality risk increased in women with breast cancer, diabetes

Although there is evidence that diabetes is associated with a small increased risk of breast cancer, women with breast cancer and diabetes have an increased all-cause mortality risk, which highlights the importance of maintaining adequate glycemic control alongside anti-cancer treatments and subsequent follow-up, according to recent study results.

Researchers included 52,657 women with type 2 diabetes, diagnosed between 1987 and 2007, and 30,210 randomly selected women without diabetes. Using Cox proportional hazards models, researchers performed a time-dependent analysis.

According to study results, diabetes was associated with a 29% increased overall breast cancer risk. However, when adjusted for age, period of cohort entry, region and BMI, the association markedly attenuated. After controlling for age, period of cohort entry, region, BMI, smoking, alcohol and deprivation, researchers also found a 49% increased all-cause mortality among women with breast cancer and pre-existing diabetes vs. women with breast cancer but without diabetes. There was weak evidence that metformin monotherapy and insulin modified breast cancer risk among women with diabetes compared with sulfonylurea.


Redaniel MTM, Jeffreys M, May MT, et al. Associations of type 2 diabetes and diabetes treatment with breast cancer risk and mortality: a population-based cohort study among British women. Cancer Causes Control. 2012.

Disclosure: The researchers have no relevant financial disclosures.

Leave a Reply

Your email address will not be published.