Combination chemotherapy for small cell carcinoma of the lung: evaluation of four-drug combination of cyclophosphamide, vincristine, methotrexate, and procarbazine.

Forty-one patients with small cell carcinoma of the lung were treated with a four-drug combination of cyclophosphamide, vincristine, methotrexate, and procarbazine. The response rate was 68% (28 responded among 41 patients), with 10 complete responses (24%) and 18 partial responses (44%). The median survival time from the initiation of chemotherapy was 11 months for patients with limited disease and 8 months for those with extensive disease. Patients who achieved complete response survived significantly longer than those who did not; the median survival time for complete responders was 14.5 months, compared to 8.5 months for partial responders and 6 months for non-responders. Myelosuppressive toxicity remained within acceptable limits, with 5% incidence of leukocytopenia (less than 1,000/microliter) and 7% incidence of thrombocytopenia (less than 50,000/microliter) following the first course of the regimen.