In a nutshell
The authors aimed to determine the link between metformin and breast cancer treatment outlook in patients with diabetes.
Some background
Metformin is a drug used to treat type 2 diabetes (condition that increases blood sugar levels). It can also have effects on cancer as it can target tumor cells (the cells that form a tumor) and hinder or stop tumor growth. This occurs by targeting tumor signalling pathways (a method of communication between tumor cells).
To date, however, the effects of metformin of breast cancer prognosis (treatment outlook) is not well studied.
Methods & findings
The aim of this study was to evaluate the treatment benefits of metformin for breast cancer in women with diabetes.
The authors aimed to evaluate the link between metformin and breast cancer outlook in diabetic breast cancer patients. A total of 6,581 women were evaluated, of whom 202 were diabetic and receiving metformin and 184 were diabetic but were not receiving metformin. Of the women treated with metformin, 107 were hormone receptor positive (HR+; cancer cells are positive for either estrogen or progesterone receptor proteins) and human epidermal growth factor receptor 2 positive (HER2+) while 33 were HR- and HER2-.
The women with HR+/HER2+ who were allocated to metformin were over 5 times more likely to survive cancer with no recurrence of the tumor (tumor comes back) compared to HR+/HER2+ patients who were not on metformin. The women negative for both HR and HER2 had only a 60% increased likelihood of survival if treated with metformin.
Overall, the women who received metformin treatment had a lower rate of recurring cancer (20.8%) than the women who did not receive metformin treatment (28.3%).
The bottom line
The authors concluded that metformin can improve the chances of survival of women with diabetes and HR+ and HER2+ breast cancer.
The fine print
Diabetic patients usually receive more than one diabetic medication.
What’s next?
If you have diabetes and have been diagnosed with HR+/HER2+ breast cancer, discuss metformin with your doctor.
Published By :
Breast cancer research
Date :
May 03, 2015
