This document summarizes the clinical features and staging of breast cancer. It describes common signs and symptoms of breast cancer such as discrete lumps, nipple retraction or discharge, skin changes like ulceration or peau d'orange appearance. Locally advanced disease is characterized by peau d'orange sign due to lymphatic obstruction. Cancer en cuirasse involves extensive skin infiltration. Distant metastasis can cause symptoms in bones, lungs, brain or other organs. The TNM staging system characterizes tumors by size (T1-4), lymph node involvement (N0-3) and presence of metastasis (M0-1).