Purpose

This randomized phase III trial studies lymph node dissection and radiation therapy to see how well it works compared to radiation therapy alone in treating patients with breast cancer previously treated with chemotherapy and surgery. Lymph node dissection may remove cancer cells that have spread to nearby lymph nodes in patients with breast cancer. Radiation therapy uses high-energy x rays or protons to kill tumor cells. It is not yet known if radiation therapy works better alone or with lymph node dissection in treating patients with breast cancer previously treated with chemotherapy and surgery.