Metformin Hydrochloride in Affecting Cytokines and Exosomes in Patients With Head and Neck Cancer

Inclusion Criteria: * Subjects with a diagnosis of head and neck cancer biopsy proven, and who are candidates for radiation therapy * All subjects must be able to comprehend and sign a written informed consent document. Exclusion Criteria: * Subjects who are pregnant or may become pregnant during metformin administration; pregnancy testing will be done in conjunction with preradiation protocols * Subjects on metformin for any reason during the preceding 4 weeks * Diabetic subjects are eligible if they are not taking metformin or insulin * Subjects who have received iodinated contrast dye must wait 12 hours prior to starting Metformin. If a CT scan with contrast is scheduled after screening and consent, the metformin cannot be taken until after the CT with contrast has been completed and they have waited 12 hours. * Patients with plasma creatinine level greater than 1.3 mg/dL * Patients with plasma bicarbonate less than 22 mEq/L or history of lactic or any other metabolic acidosis * Patients with history of congestive heart failure * Patients with myocardial ischemia or peripheral muscle ischemia * Patients with sepsis or severe infection * Patients with history of lung disease currently requiring any supplemental oxygen treatment * Patients scheduled for radiation less than 6 days from enrollment * Patients with history of hepatic dysfunction or hepatic disease and abnormal liver function tests; patients who have a history of hepatic dysfunction or hepatic disease and normal liver function tests will be eligible to participate * Patients with a current history (in the past 30 days) of heaving drinking which is defined in accordance with CDC definition as more than 8 drinks per week for women and more than 15 drinks per week for men. A standard drink contains .6 ounces of pure alcohol. Generally, this amount of pure alcohol is found in 12-ounces of beer, 8-ounces of malt liquor, 5-ounces of wine, 1.5-ounces or a "shot" of 80-proof distilled spirits or liquor (e.g., gin, rum, vodka, or whiskey). While on study, patients should limit their alcohol consumption to no more than 8 drinks per week for women and no more than 15 drinks per week for men. Patients who feel they cannot comply with this recommendation are not eligible". * All medications are permitted except those that are contraindicated with metformin under current Food and Drug Administration (FDA) recommendations