Type 2 Diabetes and Recurrence of Breast Cancer in Older Women
Posted: Friday, April 3, 2020
Among older women with invasive breast cancer, those who have more severe type 2 diabetes mellitus and the presence of macro- and microvascular complications may be at an increased risk of cancer recurrence than women with less severe diabetes complications. Abstract results (HSR20-113) were originally planned for presentation at the 2020 NCCN Annual Conference but published in JNCCN–Journal of the National Comprehensive Cancer Network. Jifang Zhou, MD, MPH, of the University of Illinois at Chicago, and colleagues, indicated that the relationship between diabetes and breast cancer recurrence may be associated with diabetes’s role in breast cancer development through insulin resistance and hyperinsulinemia on insulin-like growth factor receptors. Furthermore, decision-making for breast cancer treatment by clinicians may be affected by the severity of diabetes.
Using the Surveillance, Epidemiology, and End Results–Medicare Linked Database, the research team retrospectively analyzed 12,628 women older than age 65 who were diagnosed with stages I to III breast cancer between 2007 and 2015 and also had diabetes mellitus. The researchers used claims data to estimate the prevalence of diabetes complications and calculate time-varying Diabetes Complications Severity Index scores.
Overall, 2,134 (17%) women experienced breast cancer recurrence. The cancer recurrence rate was 58% for women with an index score greater than or equal to 2 versus 52% among women with an index score less than 2. Compared with women who had an index score of 0, those with a score greater than or equal to 3 (subdistribution hazard ratio [SHR] = 1.22) and 2 (SHR = 1.15) had an increased risk of breast cancer recurrence. Additionally, the researchers reported that macrovascular and microvascular complications, including cardiovascular disease and neuropathy, were independently associated with breast cancer recurrence.
“Further research is warranted to investigate whether diabetes mellitus control and newer generation diabetes mellitus medications with cardiovascular benefits may improve breast cancer outcomes,” the researchers concluded.
Disclosure: The authors have reported no conflicts of interest.
