The role of radiation therapy in the multidisciplinary management of recurrent and metastatic breast cancer.

Carcinoma of the breast is a disease that is associated with 10-year recurrence rates of 25% in operable patients with no spread to the axillary nodes and 75% in patients in whom the tumor has extended to the axillary nodes. Locoregional recurrence rates of close to 50% have been reported in patients with Stage III disease. Adjuvant prophylactic postoperative irradiation can reduce locoregional recurrences to less than 10%. When locoregional recurrence occurs after mastectomy, therapeutic irradiation is required. It can achieve tumor control in at least 50% of cases. The best conditions exist when a surgical procedure can achieve gross removal of the recurrent tumor before irradiation and when the fields of irradiation encompass the chest wall and pertinent lymph node areas. The required dose of radiation is lower after excision of the tumor, and the chances of local tumor control are higher. The dose of radiation must be 4500-5000 cGy (fractions of 180-200 cGy) to the subclinical disease and a boost of 1000-1500 cGy added to the known tumor areas. Distant metastatic manifestations must be dealt with for palliative purposes, except in the case of isolated supraclavicular metastasis, where radical irradiation can achieve cure. The need exists for a definition of the role of systemic therapy for locoregional recurrence, and for the development of the optimal integration of systemic chemotherapy and local radiotherapy in patients with locoregional or distant breast cancer recurrences.