Radiation therapy after high-dose chemotherapy with peripheral blood stem cell support for high-risk breast cancer.

Multidisciplinary treatment in high-risk breast cancer improves survival and local control. The feasibility and patterns of failure after several induction and high-dose consolidation regimens of chemotherapy were evaluated in this study. Between November 1990 and January 1997, 65 patients with histologically proven breast cancer American Joint Committee on Cancer stages II-III with four or more axillary lymph nodes positive or locally advanced breast cancer underwent high-dose chemotherapy (HDC) with peripheral stem cell support after surgery and induction chemotherapy. All patients were subsequently treated with radiotherapy (up to total doses of 50-60 Gy), which included the ipsilateral axilla and supraclavicular fossa and the chest wall or breast. A minimum follow-up period of 2 years from the completion of radiotherapy was required for analysis. Local control (LC), disease-free survival (DFS), overall survival (OS), and toxicity were evaluated. With a median follow-up of 62 months (range: 32-107 months), LC was 89%, and 5-year OS and DFS were 78% and 63%, respectively. Symptomatic pneumonitis developed in six patients (9%); only one patient had her radiotherapy interrupted because of hematologic toxicity. No treatment-related mortality was observed. Radiation therapy after HDC provides excellent local control rates without excessive toxicity. Delaying the start of irradiation until recovery from HDC does not seem to increase local failure rates.