Background:Previous studies suggested a link between obesity, insulin-resistance and breast cancer outcome. The aim of the present prospective observational study was to investigate the role of metabolic syndrome (MetS) and its components on early breast cancer (EBC) patients' outcome.Methods: MetS was defined by the presence of 3 to 5 of the following components: waist circumference (WC) > 88 cm, blood pressure ≥ 130/≥85 mmHg, serum levels of triglycerides (TG) ≥ 150 mg/dL, high-density lipoprotein (HDL) < 50 mg/dL and fasting glucose (FG) ≥ 110 mg/ dL (National Cholesterol Education Program Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults - NCEP-ATPIII criteria). Overall, 955 EBC patients were prospectively enrolled between January 2009 and December 2013 at University Hospital Federico II and National Cancer Institute G.Pascale, Naples, Italy …