April 3, 2012

Metformin May Slow Prostate Cancer Growth

(Ivanhoe Newswire) -- A new study shows that men with prostate cancer may be able to reduce the growth rate of cancer with the help of a commonly prescribed diabetes medication known as metformin.

Although metformin is most commonly prescribed to treat diabetes, previous studies have shown that it is capable of slowing down cancerous cells in patients with prostate cancer.

Anthony M. Joshua and colleagues, of Princess Margaret Hospital, University Health Network in Toronto, Ontario, Canada, evaluated 22 men with confirmed prostate cancer that had been assigned up to 500 mg of metformin three times a day prior to undergoing prostatectomy.

"This gave us the ability to compare what the prostate cancer looked like when it was first diagnosed to what it looked like when the prostate cancer was removed from the body," Joshua was quoted as saying.

"We were able to directly measure the effect of metformin on the prostate cancer."

Prostate cancer patients were assigned metformin for an average of 41 days. During that time, none of the men reported grade 3 adverse events, and all of them underwent prostatectomy with no adverse effect related to use of metformin.

What the team found was that metformin greatly reduced fasting glucose, insulin growth factor-1, body mass index and waist-to-hip ratio.

In addition, "although these are preliminary results, metformin appeared to reduce the growth rate of prostate cancer in a proportion of men," Joshua said.

"Also, it appeared to reduce one of the main growth pathways that may have contributed to the overall growth of the tumor."

These results may have implications for men with prostate cancer who also have diabetes or early undiagnosed diabetes and for men with prostate cancer whose tumors have characteristics that make them sensitive to metformin, according to Joshua.

"This research builds on the hypothesis that metformin has a role in prostate cancer," Joshua said.

"Exactly what that role will be will depend on the results of the analysis currently being completed by our study team and others worldwide."

SOURCE: AACR Annual Meeting 2012, March 31, 2012