Dose intensity of the CAVE regimen in small cell lung cancer correlates to response rate

Sixty-three patients with limited or extensive small cell lung cancer (SCLC), were treated in the Department of Respiratory Diseases, Huddinge Hospital, between 1985 and 1990, with chemotherapy consisting of cyclophosphamide, doxorubicin, vincristine and etoposide (CAVE). The patients were analyzed retrospectively concerning dose intensity (DI) of the chemotherapy actually delivered during induction treatment, the response rate, toxicity and survival. The mean combined relative DI (CRDI) of the induction treatment, consisting of three chemotherapy courses, was 0.7 (projected CRDI = 1.0). The overall response rate was 57% and the median survival time was 291 days. We found a correlation between the combined relative DI (all four drugs together) and the response rate. Increasing the CRDI from the range of 0.28-0.6 to 0.76-0.90 resulted in an increase in the response rate from 35 to 90%. Toxicity was scarce, suggesting that the actual delivered chemotherapy had low intensity. No correlation was found between DI and toxicity or between the response rate and toxicity. A correlation between DI of this induction treatment and survival could not be established. Our findings suggest the utility of reporting the actual DI of chemotherapy trials in SCLC.