FIVB PLUS GM-CSF IN METASTATIC COLORECTAL-CANCER

The response rate of patients with metastatic colorectal cancer to the 4-drug combination [5-Fluorouracil (5-FU), dacarbazine, vincristine a nd bis-chloronitrosourea given 5 weekly (FIVB)] was better than the re sponse rate to 5-FU. The dose limiting toxicity of the FIVB was myelos uppression. The present study investigates the effect of FIVB given wi th GM-CSF so that drug cycles could be given every 4 weeks. Thirty-fiv e ambulatory patients with measurable metastatic colorectal cancer wer e treated with FIVB plus GM-CSF 4 weekly. All patients were evaluable for toxicity. Among the 163 cycles given only 4 were delayed because o f leucopenia and 8 cycles were delayed because of gastrointestinal (GI ) toxicity. A 50% dose reduction was given to 10 patients who had Grad e 2 and 3 GI toxicity. Four of the 35 patients developed thromboemboli c complications, 2 of which were lethal. Two patients were not evaluab le for response as they were removed from study early because of toxic ity. There were 2 complete responses and 6 partial responses. The medi an time to treatment failure was 3.8 months and median survival time 9 .9 months. The addition of GM-CSF to FIVB decreased the expected leuco penia allowing drug treatment to be given 4 weekly to most patients. G I toxicity was dose limiting. Despite the increased dose intensity tha t could be delivered (to two thirds of patients), response rates were not definitely increased, no survival benefit was seen and important t hromboembolic complications occurred.