Local regional effectiveness of surgery and radiation therapy in the treatment of breast cancer.

Although gross tumor can be controlled with high doses of radiation therapy, control is achieved at the expense of severe radiation sequelae. In order to improve tumor control with minimum complications, the field of treatment should contain only subclinical disease. This article reviews the successful combination of surgery for the removal of gross cancer and radiation of moderate dose for the treatment of subclinical disease in patients with breast cancer. In patients with clinically favorable and operable disease, the combination of a radical or modified radical mastectomy and postoperative radiation therapy of 5000 rad to the peripheral lymphatics and chest wall can secure 90% of the treated areas. For patients with locally and regionally advanced breast cancer, the combination of a simple mastectomy and dissection of the lateral axilla followed by postoperative irradiation of 5000 rad in 5 weeks to the chest wall, axilla, and peripheral lymphatic areas will control more than 85% of the patients treated as compared with approximately 70% control when surgery or radiotherapy alone is used, even with chemotherapy. Yet another clinical application of the subclinical disease concept is the successful combination of conservation surgery (whether segmental mastectomy, quadrantectomy, or wide excision) for gross tumor in the breast and axilla and irradiation for residual microscopic and multiple foci of tumor, yielding more than 90% control of locoregional disease with survival rates equal to those patients treated with radical or modified radical mastectomy. Results of multiple clinical trials and reported series are reviewed.