Statins lower blood cholesterol. Metformin reduces blood sugar levels. The two may also play a role in treating prostate cancer.

Among men diagnosed with high-risk prostate cancer (who have a poor prognosis), taking a cholesterol-lowering statin medication, either by itself or with the diabetes drug metformin, is associated with a lower risk of death related to prostate cancer, according to a new study. The combination treatmetn is also associated with a lower risk of death from any cause.

Previous studies have found that both metformin and statins are associated with longer life among men with prostate cancer. Since many men take both medications together, however, it hasn’t been clear which drug was most effective in inhibiting prostate cancer and whether taking both confers an additional benefit.

Publishing their findings in Cancer Medicine, Grace Lu-Yao, PhD, the associate director of population science at the Sidney Kimmel Cancer Center–Jefferson Health at Thomas Jefferson University in Philadelphia, and colleagues analyzed data from the Surveillance, Epidemiology and End Result database as well as Medicare reimbursement data. They looked at 12,700 men diagnosed with high-risk prostate cancer between 2007 and 2011.

The median survival time following diagnosis with high-risk prostate cancer was 3.9 years among men who took both metformin and a statin. Among men who took a statin only, it was 3.6 years. Taking metformin by itself did not increase the median survival time, which for men taking that drug alone was 3.1 years, the same as in men who took neither drug.

The study authors found that the use of statins alone or in combination with metformin was associated with an overall 11% lower risk of death from any cause and a 20% lower risk of death from prostate cancer. For men who started taking these medications only after they were diagnosed with prostate cancer, the benefits were even greater: The combination of metformin and a statin was associated with a 32% lower risk of death from any cause and a 54% reduction in their risk of death from prostate cancer. Again, there was no significant association between taking metformin alone and the risk of death from any cause or from prostate cancer.

These findings provide useful insight to investigators seeking to design a randomized controlled trial in search of gold-standard proof that statins, metformin or a combination of the two extend the survival chances of men with prostate cancer. The authors concluded that the “combination of metformin and statin holds great promise for reducing all‐cause or [prostate cancer] mortality among patients with high‐risk [prostate cancer], particularly in post‐diagnostic settings.”

For more on prostate cancer, click here.

To read a press release about the study, click here.

To read the study, click here.