The Use of Metformin in Breast Cancer Treatment in Non-Diabetic Women

Abstract

Breast cancer is the second leading cause of death of women in the United States, with approximately 245,000 new cases being diagnosed each year. The current primary treatment is lumpectomy or total mastectomy, radiation therapy, along with adjuvant hormone and chemotherapy as indicated for metastatic disease. While each of these invasive treatments are effective at killing cancer cells, they are extremely toxic to every cell in the patient�s body. Metformin, a biguanide, is the most commonly prescribed drug for diabetes mellitus type 2. It�s mechanism of action works by decreasing the amount of glucose synthesized in the liver and increasing insulin sensitivity in muscle cells. Studies have already shown that diabetic patients taking metformin have a decreased risk of developing breast cancer, in addition to a better prognosis in those diagnosed with breast cancer. However, there has been no conclusion about the benefit of metformin in non-diabetic patients with breast cancer. This review presentation describes the numerous proposed anti-tumor mechanisms of metformin, such as its ability to enhance the effects chemotherapy, and inhibit cancer cell growth before and after it has begun. Metformin is a well-tolerated, inexpensive and safe medication. If its effectiveness is proven as an adjuvant treatment, breast cancer patients could reach remission with less harmful radiation and chemotherapy.