Partial Chest Wall Radiation Therapy After Surgery for Lymph Node Negative Breast Cancer

The standard treatment for breast cancer when cancer cells were found near or within the margins of the tissue that is removed during breast surgery, is radiation of the entire chest wall. This may be considered overtreatment since the only reason for doing so is that cancer cells were near or in the margins of the breast tissue that was removed. In this study, the amount of radiation treatment will be limited to the area where the remaining cancer cells were found after surgery. The purpose of this study is to find out if partial chest wall radiation therapy is as good as whole chest wall radiation therapy in reducing the risk of breast cancer cancer coming back.