The main purpose of this research is to study women who have cancer cells in the lymph nodes at the time that their breast cancer is diagnosed and have chemotherapy before surgery that clears the cancer cells from the lymph nodes.
Researchers for this study ask 1) if, after lumpectomy, radiation to the breast and lymph nodes will be better than radiation only to the breast at keeping breast cancer from returning, and 2) if, after mastectomy, radiation to the area where the breast used to be and to the lymph nodes is better than no radiation at keeping breast cancer from returning. Researchers also ask whether giving radiation as described above will help women live longer.
In order to learn more about certain features of cancer tumors and how they respond to treatment, this study includes special research tests that will be done on samples of participants' tumor tissue. This study will help researchers learn about how the study treatment affects participants' quality of life.
Approximately 10 women will take part in this study conducted by investigators at the University of Iowa. About 1,636 women from different cancer treatment centers will take part in this study.