Irradiation as the primary management of stage I and II adenocarcinoma of the breast: analysis of the RTOG breast registry.

The radiation therapy oncology group, a 36-member national study group, has collected, by means of a registry, 234 patients treated with primary irradiation for UICC Stage I and II adenocarcinoma of the breast. Analysis of these patients has revealed a 5-year actuarial survival rate of 83% for Stage I and 68% for Stage II. The local-regional failure rate for all 234 patients was 8.5% (20/234), and 16.6% (17/102) for those patients followed for a minimum of 3 years. The local failure rate for T1 tumors was negligible, being 1.7% (2/117), regardless of whether or not complete excision of tumor was performed prior to irradiation. For T2 tumors, the local failure rate was 9.7% (9/93) if there was preirradiation tumor excision, but increased to 29.2% (7/24) if the preirradiation surgery was limited to incisional or needle biopsy only. There were six severe complications (2.6%), and all of these were cases of breast fibrosis. There were 14 other complications but these were judged to be of only mild to moderate severity. Eighty-four percent of the patients had an acceptable cosmetic result with either no difference or only a mild to moderate difference between the treated and untreated breast.