The impact of primary irradiation treatment of localized breast cancer on the ability to administer systemic adjuvant chemotherapy

Abstract

The impact of primary irradiation of localized breast cancer on the ability to administer Adriamycin-cytoxan adjuvant chemotherapy to patients with stage II breast cancer was examined. Patients were prospectively randomized to receive either irradiation or mastectomy as local therapy and did not differ with respect to other prognostic variables that might influence tolerance to chemotherapy. All of the patients received chemotherapy dose escalations (or reductions) until maximal tolerated drug doses were established. Patients receiving irradiation had minimally greater myelosuppression which was nearly totally explainable by lymphopenia. Irradiated patients required dose reduction nearly twice as often as mastectomy patients although commonly their dose could be reescalated. Patients managed with radiotherapy received slightly less drug than patients treated with mastectomy when treated to an identical degree of bone marrow suppression. The primary management of breast cancer by irradiation does not induce substantial changes in the ability of patients to tolerate adjuvant chemotherapy.