Now these studies show exciting potential!
Metformin May Be Key to Preventing Colorectal, Other Cancers
Elsevier Global Medical News. 2010 Sept 1, MG Sullivan
The first human trial of metformin for precancerous colorectal lesions hints that the diabetes drug may be poised for a second incarnation – this time as a chemopreventive agent for several cancers, including lung, colon, and prostate cancers, and even breast malignancies.
The small study, published in the September issue of Cancer Prevention Research, found that after 1 month of oral metformin, nondiabetic patients who already had at least one colorectal adenoma removed experienced a significant reduction in their number of colorectal aberrant crypt foci – an endoscopic finding that some consider a precursor of adenomatous colon polyps.
A second study, published in the same issue of the journal, found that mice who received the drug after exposure to a potent lung carcinogen developed significantly fewer lung tumors than did those who received a placebo.
In light of these data, physicians may want to look closely at metformin when choosing an oral antidiabetic agent for their patients, Dr. Phillip Dennis of the National Cancer Institute said during a press briefing Sept. 1.
“It’s true that we don’t have an indication for metformin as a cancer chemopreventive,” said Dr. Dennis, lead author of the mouse study. “But a clinician who has four different oral agents for diabetes has to make a choice for his patients, and in that process, this early evidence that metformin may have an oncologic benefit will certainly play a role.”
A growing body of data suggests that metformin reduces the risk of several types of cancer, but thus far the only human evidence had come from observational studies of patients with diabetes. Three epidemiologic studies suggest that metformin decreases the incidence of cancer and cancer-related deaths in diabetic patients by 15%-77% (Euro. J. Cancer 2010;46:2369-2380). In vitro and animal studies suggest similar reductions.
The study released today shows the drug’s potential not only to reduce the number of precancerous lesions, but also to decrease the level of proliferating cell nuclear antigen (PCNA), a marker of tumor virulence, wrote Dr. Kunihiro Hosono of the Yokohama City University School of Medicine, Japan, and colleagues: “This first reported trial of metformin for inhibiting colorectal carcinogenesis in humans provides preliminary evidence that metformin suppresses colonic epithelial proliferation and rectal aberrant crypt foci, suggesting its promise for the chemoprevention of colorectal cancer” (Cancer Prev. Res. 2010;3:1077-83).
Read more, including a report about a promising lung cancer study in mice. Here is the link: OncologyStat/Metformin.
A diabetes drug that may help prevent cancer? Why not!
Feel good and keep smiling! Pat