Team study raises questions about drug’s ability to prevent breast cancer

The Hormel Institute - cover March 2015

A microscopic image related to breast cancer by researchers at The Hormel Institute, University of Minnesota has been featured on a leading scientific journal’s cover.

The image featured on the March 2015 cover of Cancer Prevention Research, a journal published by the American Association for Cancer Research, came from the “Cancer Biomarkers and Drug Resistance” research section led by Dr. Ann M. Bode, Associate Director of The Hormel Institute. Staining for the image was performed by senior laboratory technician Alyssa Langfald.

Dr. Ann Bode

Dr. Bode collaborated on a project studying the cancer-preventive qualities of a diabetes drug called metformin with researchers from the National Cancer Institute, Bethesda, Maryland; University of Alabama at Birmingham, Alabama; Mayo Clinic Cancer Center in Rochester; and Huntsman Cancer Institute, Salt Lake City, Utah.

“Our work focuses on looking for and visualizing tissue biomarkers to determine whether a drug is effective in treating or preventing cancer, and Ms. Langfald is obviously quite skilled in this technology,” said Dr. Bode, who also co-leads The Hormel Institute’s “Cellular and Molecular Biology” research section and serves as the administrative director for the cancer research center.

“Even though the drug was ineffective in changing tumor growth in a variety of experimental laboratory models,” she said, “it still might be useful or effective in specific subgroups of individuals at high risk for certain types of cancers. Only a clinic trial targeting those subgroups will be able to determine its efficacy.”

In the published study, the team of researchers – in anticipation of using metformin in clinical trials in nondiabetic women – studied metformin’s effectiveness in preventing breast cancer in nondiabetic animal models commonly used in mammary cancer projects. Researchers found a lack of efficacy from using metformin, calling the results “somewhat disconcerting,” but noting that metformin’s cancer-preventive qualities possibly could be observed in models with the altered physiology associated with diabetes or prediabetes.

Used worldwide by about 120 million people, metformin has drawn great interest in recent years as a potential chemopreventive/therapeutic agent due to epidemiologic studies showing a lower incidence of cancer – especially in breast cancer – and lower toxicity in diabetics taking metformin compared with those taking other antidiabetic agents.

There also has been great enthusiasm for potentially using metformin due to its relatively low toxicity and that it alters energy metabolism, which is believed to be altered in most cancers.