464 yount patients (YP; 20–35 years old) and 748 postmenopausal patients (PMP; 65–75 years old) with breast cancer during 1999-2005 and with complete data for ER, PR, Her2neu, nuclear grade, stage, lymphovascular invasion (LVI), nodal status, treatment details, and race were analyzed. Patients were divided into Luminal A (ER/PR positive, Her2neu negative), Luminal B (ER/PR positive, Her2neu positive), Her2neu (ER/PR negative, Her2neu positive), and triple negative (ER/PR negative, Her2neu negative) categories. Univariate and multivariate analysis was performed using overall survival (OS). All of the previously listed variables showed significant difference between the YP and the PMP except for the percentage of patients receiving radiation ( p <... sp="0.25"/>0.0001). In multivariate analysis of OS for both groups taken together, age was not a significant predictor. However, breast cancer subtype, stage, LVI, nodal status, chemotherapy, and type of surgical procedure are significant predictors of OS. For YP alone, OS is dependent upon breast cancer subtype, nuclear grade, stage, LVI, and type of surgical procedure. For PMP alone OS is breast cancer subtype and nodal status. We conclude that the higher prevalence of more aggressive breast cancer, and the prevalence of higher stage due to lack of screening, in younger women accounts for these differences.