Metformin does not significantly improve survival in men with advanced prostate cancer, but it does help reduce some of the harmful side effects of hormone therapy, a major clinical trial has found.

 

The findings come from the latest phase of the STAMPEDE trial, a large UK-based study investigating new treatment options for prostate cancer. Researchers tested whether adding metformin to standard care would benefit men with metastatic hormone-sensitive prostate cancer who did not have diabetes.

 

Nearly 2,000 patients were randomly assigned to receive either standard treatment, which included androgen-deprivation therapy (ADT), and in some cases radiotherapy, chemotherapy (docetaxel), or advanced hormone therapy (ARPI) or the same care plus metformin, taken twice daily.

 

The results showed little difference in overall survival. Median survival in the standard care group was 61.8 months, compared to 67.4 months in the metformin group. This difference was not statistically significant (hazard ratio 0.91; p = 0.15), meaning metformin did not clearly prolong life.

 

However, researchers did find that patients taking metformin experienced fewer of the metabolic side effects commonly caused by ADT, such as weight gain and insulin resistance.

 

While the drug may not improve survival in this setting, the findings suggest it could play a role in reducing treatment-related complications and improving quality of life for prostate cancer patients on hormone therapy.

 

The study was published in The Lancet Oncology recently.