Chemotherapy response after initial treatment failure in small cell bronchogenic carcinoma

Fifteen patients with small cell lung cancer (S.C.) (13 extensive disease, 2 limited disease) were studied. All patients had progressed on their primary chemotherapy of CCNU 50-100 mg/m² P.O. q6w, cytoxan (CTX) 500-1000 mg/m² I.V. q3w, and methotrexate (MTX) 10-15 mg/m² P.O. or I.V. biw. The chemotherapy regimen evaluated consisted of adriamycin (ADR) 60 mg/m² I.V. q3w, vincristine (VCR) 1.4 mg/m² I.V. q3w, and procarbazine (PROC) 100 mg P.O. qd X 1 q3w. Twelve patients were ambulatory ≥ 50% of the time at the start of therapy. Antitumor responses were noted in 8 of the 15 patients (53%) with 1 complete response and 7 partial responses. Another 3 patients had disease stabilization for at least one month. Only patients who were ambulatory at the start of treatment responded. The median duration of response is presently 110 days (range 31 days to 172+ days). Dose limiting toxicities of this regimen included VCR neurotoxicity, PROC induced gastrointestinal toxicity and moderate myelosuppression. Failure on a previous therapy, therefore, does not preclude subsequent therapeutic response in S.C. carcinoma so long as patient performance status is good. The combination of ADR, VCR, and PROC is active in this patient population.