There are several independent but interrelated prognostic factors predictive of recurrence and survival in breast cancer. These include axillary nodal status, histopathology, steroid receptors, proliferative rate, ploidy, and oncogene amplification. Axillary nodal status has been the traditional mainstay predictor for recurrence and survival in primary breast cancer. In addition, the presence of the estrogen and progesterone receptors has correlated with longer disease-free interval and overall survival in stage I and II breast cancer. Thymidine-labeling index and percent S-phase as measured by flow cytometry are indices of cell proliferation that correlate with relapse rate in pre- and postmenopausal women with breast cancer. Estrogen and progesterone receptor-negative tumors are more commonly aneuploid, and have higher percent S-phase, factors that predict for recurrence in Stage I breast cancer.