This document outlines the staging system for breast cancer. Stage 0 is carcinoma in situ with no lymph node or distant metastasis. Stages 1-3 classify tumors based on size and extent of local and regional lymph node involvement. Stage 4 is any tumor with distant metastasis. Common chemotherapy regimens for breast cancer are listed, including CMF, FAC, and AC. Trastuzumab and Laptinib are targeted therapies for HER2 positive breast cancer.