Prostate Cancer and Type 2 Diabetes: Focus on Outcomes and Metformin
Posted: Monday, October 5, 2020
Previous studies have suggested that metformin may have anticancer properties, although it is not well understood whether the diabetic medication may affect prostate cancer survival outcomes. Giedre Smailyte, PhD, of the National Cancer Institute, Vilnius, Lithuania, and colleagues found that long-term prostate cancer–specific survival did not appear to differ between patients with or without preexisting diabetes treated with metformin. However, the results of the nationwide population-based study suggested overall survival rates seemed to be lower in patients with type 2 diabetes who were not treated with metformin. The findings were published in the Scandinavian Journal of Urology.
Using the Lithuanian Cancer Registry, the study authors identified more than 6,500 men diagnosed with prostate cancer. Of those patients, 254 men (3.8%) had preexisting type 2 diabetes. The researchers obtained patient information on diabetes diagnoses and antihyperglycemic medications from the National Health Insurance Fund database.
Although the investigators did not observe any difference in cancer-specific survival between men with or without preexisting diabetes, the risk of overall mortality was higher in men with diabetes (hazard ratio [HR] = 1.24). A patient’s age and cancer stage at diagnosis were both found to be significant predictors of survival.
After adjusting for age and cancer stage at diagnosis among patients without diabetes, the investigators did not find any differences in cancer-specific mortality between those who received metformin and those who did not. In addition, preexisting diabetes did not significantly affect cancer-specific mortality among metformin users (HR = .74). Overall, 4,807 men died during follow-up, including 2,084 of prostate cancer.
Disclosure: The study authors reported no conflicts of interest.