Radiotherapy for the prevention of local-regional recurrence in high risk patients post mastectomy receiving adjuvant chemotherapy.

From 1977 to 1986, 63 patients at high risk for isolated local-regional recurrence following mastectomy and adjuvant chemotherapy received post-operative radiotherapy. All patients had operable primary tumors (T1-3a). For entire group the mean and median number of positive nodes were 10 and 8, respectively. Radiotherapy consisted of 4500 to 5000 rad to the chest wall and regional nodes. Chemotherapy consisted of CMF +/- prednisone (45 patients), CAF (16 patients), and other variable regimens (2 patients). Relapse occurred in 23 patients with only two patients experiencing an isolated local-regional recurrence. In 3 patients local-regional recurrence appeared simultaneously with or following distant metastases and in 18 patients the pattern of failure was distant metastases alone. With a median follow-up of 28 months (range 9-87 mo.), 40 patients are alive without disease, 9 are alive with disease, and 14 have died with disease. The 4-year actuarial overall survival is 67% and the 4-year actuarial disease-free survival is 47%. The 4-year actuarial probability of an isolated local-regional recurrence is 5%. Complications related to the radiation included a 9% incidence of moderate to severe arm edema. This study demonstrates the ability of radiation to reduce the incidence of local-regional recurrence in a previously identified high risk group of patients and has produced encouraging survival results with minimal morbidity.