Diabetes drug may treat cancer
Metformin, used to treat diabetes, just may also beat down cancer cells through a multi-pronged defense, and for much less money than current gold standard treatments ($30 to $50 a month to the patient.) The findings (reported by the American Association for Cancer Research) which looked at breast, prostate and pancreatic cancers require further investigation. But this is what they show to date:
How does metformin work against cancer?
First, metformin decreases insulin, associated with speeding growth of cancer cells. The drug activates the AMP kinase sensor. Put simply, activation of this sensor sets off a molecular reaction that controls cell division and growth. And preliminary studies show metformin affects the mTOR pathway; mTOR is a protein that promotes cancer growth.
One landmark study focused on men with prostate cancer.
Trial participants who took metformin daily from the time of diagnosis through prostate removal had a 32 percent reduction in tumor growth in that time frame. Their blood levels of insulin dropped significantly. And metformin shut down the mTOR pathway.
Additionally, metformin appears to slow the metabolism of cancer cells, causing them to die off. Further research is needed to determine if “cure” rates will correlate with these promising results.
An interesting study in patients with pancreatic cancer.
There is a correlation between diabetes and risk for pancreatic cancer (10% of such cancers are associated with diabetes). Twice as many trial participants with pancreatic cancer and diabetes on metformin were alive two years after diagnosis than those who did not take the drug (30% vs 15%). Overall survival increased by four months.
Metformin appears to treat breast cancer too.
Researchers at MD Anderson (Houston, TX) identified 2,529 breast cancer survivors who received chemotherapy before surgery. They included diabetics on metformin, diabetics who didn’t take metformin, and nondiabetics.
On completion of chemotherapy, 24 percent of diabetics taking metformin were free of breast cancer, versus 8 percent of diabetics not taking metformin. But the drug may benefit nondiabietic breast cancer patients too: 16% of women in this group on metformin were cancer free after chemo (keep in mind this number reflects results BEFORE surgery; surgery is more ammo to boost outcomes).
MD Anderson plans to open a clinical trial with metformin in combination with hormonal therapy for obese metastatic breast cancer patients.
And researchers are working to determine whether metformin’s cancer-fighting benefits are exclusively tied to its ability to lower insulin—or whether the drug actually works directly to destroy cancer cells.
Brand names for metformin are Glucophage, Glucophage XR, Glumetza, Fortamet, and Riomet.
Metformin and prostate and pancreatic cancers
Metformin and breast cancer
Clinical trials on metformin for cancer