- Cancer is a deadly disease whose incidence is increasing globally at an alarming rate
- Diabetes treatment drug such as metformin's insulin-lowering action could also contribute to its anti-neoplastic action.
- Improved outcomes in tumors were seen particularly in head and neck cancer patients when metformin was added to the chemotherapy and radiation treatment regimen.
Type 2 diabetes and cancer have many risk factors in common and some studies have shown that medications used to treat diabetes are associated with reduced risk of certain kinds of cancer.
Researchers at the University of Cincinnati (UC) College of Medicine have now found a link between metformin treatment and cancer prognosis particularly the head and neck cancer type. Studies proved that a slow escalation of metformin dose added to chemotherapy and radiation treatment regimen could have a beneficial effect in head and neck cancer patients. However if the dose is escalated too quickly, then it might not be well tolerated by patients.
The findings of the study were presented via poster presentation in American Society of Clinical Oncology (ASCO) Annual Meeting: Collective Wisdom held in Chicago.
Trisha Wise-Draper, MD, PhD, who is the lead investigator of the study and assistant professor in the Division of Hematology Oncology at the UC College of Medicine, a member of both the Cincinnati Cancer Center and UC Cancer Institute said that retrospective studies have shown improved outcomes in tumors treated with chemotherapy and radiation when patients were also given metformin for diabetes.
Dr. Wise-Draper stated, "In head and neck squamous cell carcinoma, which develops in the mucous membranes of the mouth, nose and throat, diabetic patients taking a medication called metformin had better overall survival compared to those not on metformin when also treated with chemotherapy and radiation. Additionally, pancreatic cancer patients treated with chemotherapy and metformin required higher doses of metformin - 1,000 milligrams twice a day - to experience positive results".
She further commented "In basic science studies, metformin has been shown to stop mTOR, a molecular pathway present and active in this type of head and neck cancer, and pretreatment with metformin resulted in a decrease in the occurrence of oral cavity tumors in animal models. In this study, we wanted to see if the combination of escalating doses of metformin with the chemotherapy agent cisplatin and radiation for head and neck cancer tumors in non-diabetic patients would be effective."
Hence, the study protocol was modified to allow slower escalation over a period of 14 days. No substantial change in T cell or glucose levels was seen with the administration of metformin in the small sample of patients, but it was noted that there was increased C-peptide levels in response to metformin administration.
Commonly reported side effects in patients included nausea (71 %) and vomiting (43 %), increase in creatinine (57 %), decreased white blood cell count (43 %) and pain when swallowing (43 %). The researchers attributed only nausea to metformin and the rest to cisplatin and radiation therapy.
These results demonstrated that the combination of metformin and cisplatin and radiation was poorly tolerated when metformin was escalated quickly. However, no significant increase in side effects was seen with the addition of metformin.
The authors are continuing the study for a longer period of time with a possibly increased sample size in a quest for providing more definitive and conclusive evidence in the near future.