Metformin As an Addition to Conventional Chemotherapy in Breast Cancer

metformin inbreast cancer may be related to activation of adenosine monophosphate‐activated protein kinase, which may ultimately result in a rapid inhibition of cellular protein synthesis and growth of tumor cells. We suggest, however, that additional mechanisms may play a part. It is a well-accepted fact that chronic inflammation is a major contributory factor to cancer development and progression, and elevated levels of various nonspecific markers of inflammation in the serum have been shown to be associated with poor survival in a number of different cancers. Pierce et al 3 have recently assessed the relationship between circulating levels of C-reactive protein and serum amyloid A and breast cancer survival. They showed that raised levels of these inflammatory markers were associated with a significantly reduced overall survival and a trend toward a reduced diseasefreesurvival.Patientswithtype2diabetesmellitustendtohavehigher C-reactive protein concentrations than those without it, suggesting that inflammation may contribute to the higher risk of breast cancer and worse prognosis of malignant disease in these patients. 4 Thereisevidencetosuggestthatmetforminhasapositiveimpact on inflammation and endothelial dysfunction. Metformin was compared with another oral hypoglycaemic agent, repaglinide, in nonobese patients with type 2 diabetes and shown to be more effective in