The impact of dose intensity of standard chemotherapy regimens in extensive stage small cell lung cancer

Oncologists often attenuate the doses of chemotherapy drugs in published standard regimens to avoid toxicity. The impact on survival of this practice in patients with extensive stage small cell lung cancer (SCLC) is uncertain. We have compared the outcome of 85 patients treated with a program of cyclophosphamide, doxorubicin, and vincristine to a group of 37 patients treated with conventional regimens of higher dose intensity. The two groups of patients were shown to be equivalent in terms of staging evaluation, response and survival criteria, and pretreatment prognostic factors. The latter was confirmed by applying a published prognostic algorithm. Complete response rates (38% vs 14%) were significantly better with the higher intensity regimens (p = .003). The median survival (39 vs 26 weeks), 1 year survival (32% vs 12%), and overall survival (p = .002) were superior with the full-dose intensity protocols. Myelotoxicity was also greater with the contemporary treatments. Cox proportional hazards analysis, correcting for pretreatment prognostic variables, confirmed the improved survival with conventional doses of therapy (p = .0055). These results support the concept that full-dose intensity chemotherapy provides survival benefit in patients with extensive stage SCLC.