Short perioperative versus long-term adjuvant chemotherapy.

A single course of cyclophosphamide IV 5 mg/kg daily for 6 days was given immediately after mastectomy to 507 patients (519 randomized controls). The relapse-free rates were significantly increased, and after 16 years the difference was 12%. In a parallel series the same adjuvant course was given 2-4 weeks after mastectomy to 52 patients (58 randomized controls). No effect of this delayed course was found. In a second study a short multidrug course was given to all patients immediately after mastectomy. One-half of the axillary node-positive cases were randomized to continue with IV CMF for 1 year. The preliminary observations show that the prolonged treatment improved the relapse-free rates significantly during the first few years. One year after mastectomy the difference was 10%; after 2 years, 9%; after 3 years, 11%; and after 4 years, 9%. The side-effects of the short course were negligible, but the side-effects of prolonged treatment were considerable and increased with increasing treatment duration. More trials are needed to find the optimum duration of adjuvant chemotherapy.