Five-year results of a randomized clinical trial comparing modified radical mastectomy and extended radical mastectomy for stage II breast cancer.

A controlled cooperative study was carried out to assess the value of modified radical mastectomy for patients with stage II breast cancer. The data was analyzed from 11 institutions in the Shikoku District participating in a prospective clinical trial in which patients were randomly assigned either to a modified radical mastectomy group or an extended radical mastectomy group. These two groups of patients were similar to each other in terms of such background factors as age distribution, menopausal status, TNM classification, tumor size, location of the primary tumor, axillary nodal involvement, histological type, and estrogen receptor status. The median follow-up times in the modified and extended radical mastectomy groups were 4.7 and 4.5 years, respectively. The cumulative curves indicated no difference between the two groups in either disease-free survival or overall survival. The survival rates were classified according to the presence or absence of axillary nodal metastases. However, no significant difference was found between the two groups. These findings thus suggest that the routine removal of the grossly uninvolved major pectoral muscle and parasternal lymph nodes is not necessary in patients with stage II breast cancer.