The Facts About Metformin (Glucophage) & Breast Cancer
May 10th, 2010 | Published in Diabetes Treatment
If you have diabetes, you may have a higher risk of redeveloping a cancer that was previously diagnosed or developing different types of cancer. Females who are obese and have diabetes have a greater chance of developing recurrent breast cancer. One of the reasons may be that higher insulin levels cause cancer cells to grow and divide faster. Other molecules that are associated with diabetes such as insulin-like growth factor (IGF) may also cause cancer cells to multiply.
One of the most common oral prescription drugs for treating diabetes is Metformin, which is also called Glucophage. Studies have revealed that this drug may be effective in lowering the risk of cancer-related death by reducing the proliferation of cancer cells. Unfortunately, there is minimal clinical research evident to prove this.
The Journal of Clinical Oncology published a new study that indicates that Metformin is a possible breast cancer treatment option. The M.D. Anderson Cancer Center obtained medical records from 2,529 patients who underwent an initial treatment of neoadjuvant chemotherapy between 1990 and 2007 to treat their early stage breast cancer. The group of patients included 68 patients with diabetes who took Metformin, 87 individuals with diabetes who did not take the drug, and 2,374 individuals who were not diabetic. All of the patients later underwent surgery to treat their breast cancer, at which point the researchers examined each individual’s response to their initial chemotherapy treatment.
Once a pathologist can no longer find any evidence of cancer after removing the cancer cells from the site, the chemotherapy response is considered pathologically complete. This pathological complete response normally results in a better prognosis after neoadjuvant chemotherapy. Therefore, this type of response was monitored in each of the three female groups who participated in the study after they underwent neoadjuvant chemotherapy.
The women with diabetes who took Metformin were discovered with a pathological complete response to neoadjuvant chemotherapy that was 3 times higher than the women with diabetes who did not take the drug. There was no significant different between the women who were not diabetic and the women with diabetes who took Metformin. However, the pathological complete response was better for the women in the latter group.
Although the low number of women who were diabetic in the study and its retrospective nature make it difficult to draw relevant conclusions, the results coincide with the findings of previous research studies. Therefore, the data points to the fact that Metformin may be effective in counteracting the effects that diabetes has on breast cancer cells. One question that results is whether women with diabetes and breast cancer should be automatically treated with Metformin. The study revealed an insignificant improvement in the rates of pathological complete response for women with diabetes who take Metformin compared to women without diabetes. Consequently, more thorough clinical studies may reveal whether Metformin may also be useful to treat breast cancer for women without diabetes.
There are several clinical research trials currently in progress that examine Metformin’s role in breast cancer management and one trial for prostate cancer. The hope is that some of these trials will shed some light on Metformin’s role concerning breast cancer therapy for women who are diagnosed with diabetes as well as non-diabetic women. If you have diabetes and have survived breast cancer, you may want to discuss taking Metformin with your doctor.