Metformin Use Linked to Endometrial Cancer Incidence, Outcomes

Results of a meta-analysis showed an association between metformin use and an increased risk of endometrial cancer among patients with type 2 diabetes. However, researchers also found that metformin use was associated with a lower risk of death and longer progression-free survival (PFS) among patients who had endometrial cancer.

This meta-analysis of 28 studies was published in Gynecologic Oncology. The researchers analyzed data from 24 retrospective observational studies and 4 case-control studies. The studies included women with type 2 diabetes who were or were not taking metformin.

A higher risk of endometrial cancer was seen in patients who were taking metformin (hazard ratio [HR], 1.17; 95% CI, 1.09-1.25; P <.0001).

Among patients with endometrial cancer, metformin use was significantly associated with longer PFS (HR, 0.55; 95% CI, 0.44-0.68; P <.00001).

Metformin use was also associated with a lower risk of endometrial cancer-specific mortality (HR, 0.95; 95% CI, 0.90-1.00; P =.03) and all-cause mortality (HR, 0.62; 95% CI, 0.52-0.74; P <.00001).

“[T]he results from our meta-analyses must be interpreted cautiously due to methodological bias and a very low rating using GRADE,” the researchers noted. “Observational studies in the context of metformin and cancer therapy are complex as the management of diabetes changes over time, and the presence of time-related biases is challenging to detect. More clinical trials and further larger, prospective studies are warranted to evaluate the therapeutic use of metformin in EC [endometrial cancer] to draw safe and definitive conclusions.”

This article originally appeared on Cancer Therapy Advisor