written by Michael O’Leary
Metformin may be the aspirin of type 2 diabetes. It just seems as if the benefits of metformin therapy seem to grow the more researchers study it.
A case in point is new study published online last week in the Journal of Clinical Oncology.  It showed that men with type 2 diabetes and prostate cancer lived longer and were much less likely to die of prostate cancer when treated with metformin.

This was a retrospective study, meaning they analyzed information already collected for other reasons and stored in a database. In this case the researchers searched the Ontario Diabetes Database to identify all men 66 years or older who had been diagnosed with diabetes between 1997 and 2008. They then cross-referenced those with men diagnosed with prostate cancer after being diagnosed with type 2 diabetes.
The result of those searches produced a study group of 3,837 with a median age of 75 at the time of being diagnosed with prostate cancer. A total of 976 patients had high-grade, aggressive tumors at diagnosis, and 2,167 had high-volume tumors (greater than 30 percent). During the study period 1,343 died, and 291 of those died of prostate cancer.
When they analyzed multiple variables they found that for each six months of taking metformin, there was a 24 percent reduction in prostate cancer deaths as compared to men who did not take metformin. That result remained regardless of they type of prostate cancer treatment the men underwent.
When they looked at all causes of death there was a 24 percent reduction in prostate cancer deaths during the first six months of treatment with metformin, but that effect gradually diminished to a 7 percent reduction in dying from all cancer for those who took metformin for 24 to 30 months.
For the 850 men who took metformin alone for their diabetes, the risk of dying of prostate cancer was 44 percent lower and the risk of dying from all causes was 20 percent lower.
While this is an observational study with many limitations, it adds to the many studies showing metformin directly or indirectly affecting cancer cells ability to grow and reproduce, in other cancers including breast, prostate, lung, and endometrial cancer.