There is growing evidence that the diabetes drug metformin can help fight cancer, including colon, breast, prostate and lung cancer.
Metformin Against Lung Cancer:
The latest study suggests that the drug makes non-small cell lung cancer cells more susceptible to radiation treatment. Scientists at the University of Pennsylvania presented evidence from a pilot study at the 15th World Conference on Lung Cancer. In a pilot study, 16 patients with both diabetes and non-small cell lung cancer were treated with chemotherapy, radiation and metformin. Their rates of recurrence were lower than those of patients who did not get the diabetes drug.
More recently, a trial including 682 lung cancer patients undergoing chemo and radiotherapy showed better survival for those who were also taking metformin (Radiotherapy and Oncology, March, 2016). More trials are needed to verify that metformin has value as an adjunctive treatment for lung cancer.
Studies in mice also indicate that metformin is a radiosensitizing agent for non-small cell lung cancer cells (British Journal of Cancer, May 28, 2013).
Metformin and Other Types of Cancer:
A recent review of studies tracking the use of metformin for prostate cancer concluded that it is not helpful in preventing this cancer; it can, however, be useful when added to androgen-suppressing therapy or external-beam radiation therapy (Urologic Oncology, online Nov. 8, 2016).
Gastrointestinal Cancers:
Other researchers are hunting down the exact ways that metformin can help discourage colorectal cancer. It induces programmed cell death (apoptosis), which untreated cancer cells usually escape (Frontiers in Bioscience–Landmark Edition, Jan. 1, 2017). Metformin also enhances the impact of radiation on liver cancer cells (Oncotarget, online Oct. 27, 2016).
Brain Cancers:
It has been proposed as an add-on to chemotherapy for the brain cancer neuroblastoma (PPAR Research, online Oct. 5, 2016). In treating another brain cancer, glioblastoma multiforma, metformin can reduce the resistance of glioma cells to the chemotherapeutic agent temozolomide (Oncotarget, Oct. 24, 2016).
By itself, metformin is not strong enough to be used as an anti-cancer treatment. In combination with other such treatments, however, it appears to make cancer cells more vulnerable and improve the outcome (Pharmacological Research, Nov., 2016).
What Else Is Metformin Used For?
Metformin is probably the first line for drug treatment of type 2 (non-insulin-dependent) diabetes. For more information on controlling blood sugar with and without medications, we offer our Guide to Managing Diabetes.
Metformin has also been used to treat prediabetes, to keep it from becoming frank diabetes (Endocrine, online Oct. 15, 2016; Diabetes Care, Oct., 2016). Here too metformin was most effective in addition to other interventions, in this case exercise and dietary changes.
Polycystic ovary syndrome (PCOS) causes a lot of distress in the women who have it. It can also interfere with fertility. An Italian study found that metformin could be effective in helping these women reduce their body mass index (BMI), improve their insulin sensitivity and regularize their menstrual cycles (Gynecological Endocrinology, online Nov. 3, 2016).
Revised 11/18/16
