Metformin Deprives Head and Neck Cancer Cells of Energy Source

Common diabetes drug changes the biology of cancer cells.

Patients who take metformin for diabetes may have better outcomes for head and neck cancer compared with non-diabetic patients.

In a study published in The Laryngoscope, investigators found that metformin altered the tumor’s microenvironment, making them more vulnerable to treatment.

“Because tumors need a lot of energy to grow quickly, throwing a wrench in their energy-production pathway makes this kind of cancer more susceptible to standard therapies,” said first author Joseph Curry, MD.

For the study, investigators treated 39 patients with metformin and examined their tumor samples before and after treatment. Participants received doses at about half of the levels received by patients with diabetes.

The investigators examined the molecular markers of apoptosis, as well as changes in metabolic pathways that could make the cancer more susceptible to standard therapy.

The results of the study showed that patients treated with metformin had a significant increase in tumor cell apoptosis. Furthermore, the fibroblasts surrounding the cell showed signs of deterioration, indicating that the cells were less capable of helping neighboring cancer cells grow and spread to other areas of the body, according to the study.

There were few reports of adverse events (AEs) from metformin, but for patients who did experience AEs, they were considered low grade. None of the patients experienced any high-grade AEs.

“The study demonstrates that metformin has effects on head and neck cancers, at safe doses, that are at or lower than what is given to diabetic patients and that it changes head and neck tumor biology in a way that likely makes the cancer easier to kill,” said co-author Madalina Tuluc, MD, PhD. “Metformin disrupts the cancer’s most efficient method of generating fuel for its growth and shuts of the cancer’s support system.”

The next step would include testing the doses of metformin in phase 2 clinical trials with a larger number of patients, the authors concluded.