Partial (segmental) mastectomy surgery involves removing more of the breast tissue than in a lumpectomy. In this surgery, the cancer is removed along with some of the breast tissue around the tumor and the lining over the chest muscles below the tumor. Usually, some of the lymph nodes under the arm are also taken out. Your doctor may recommend the same follow-up treatment plan for radiation therapy and/or chemotherapy following this kind of surgery as with a lumpectomy.
Breast experts generally agree that for most women with early stage breast cancer (I or II); breast-conservation surgery (lumpectomy/partial mastectomy plus radiation therapy) is as effective as mastectomy. The survival rates of women treated with these two approaches are the same.