SAN ANTONIO (EGMN) - Metformin, an old and familiar diabetes drug, might have a future in the prevention and adjuvant therapy of breast cancer. Accumulating evidence from epidemiologic, cell culture, and animal studies suggests that metformin has an antineoplastic effect. The drug is in ongoing randomized clinical trials with biomarker end points in breast cancer patients. If outcomes prove favorable, larger trials with clinical end points in the prevention and adjuvant settings are likely, Dr. Michael...