A Prospective Randomized Trial of Methyl-CCNU, 5-Fluorouracil (5-FU) and Vincristine (MOF) Versus MOF Plus Streptozotocin (MOF-Strep) A prospective randomized trial evaluated semustine (Methyl CCNU) 5-Fluorouracil (5-FU) and vincristine (MOF) versus MOF plus streptozotocin (MOF-Strep) in 75 patients with advanced, measurable colorectal carcinoma. The complete and partial remission rate with MOF-Strep was significantly better, 34 versus 5% with MOF ( P = 0.003). Gastrointestinal toxicity was increased with the addition of streptozotocin. Initial patient characteristics such as age, sex, performance status, time from diagnosis to metastatic disease, site of metastatic disease, and most initial laboratory values were not predictive of response. However, certain initial laboratory values (lactic dehydrogenace and leukocyte count) and one tumor site pulmonary metastases did influence survival regardless of response. Cancer 51:ZO-24, 1983. DVANCED COLORECTAL CARCINOMA has been and A still is a challenging problem. In 1975, Moertel et af.' reported a 43% response rate with a combination drug regimen of methyl-CCNU (MeCCNU), 5-fluorouracil (5-FU) and vincristine (MOF) in patients with metastatic colorectal carcinoma. Four subsequent investigators listed in Table 1 used similar doses of 5-FU and obtained a response rate ranging from 40-32%.
Bruckner et af.,' using a higher dose of 5-FU given by a 24-hour infusion method, obtained only a 16% rate in 132 patients, and Moerte16 reporting now on a larger number of patients (127) obtained a 27% response rate. Three other investigators using lower doses of 5-FU obtained lower response rates, ranging from 4-12% (Table ). At Memorial Sloan-Kettering Cancer Center (MSKCC), the MOF combination was tested using two different regimens: a single dose of MeCCNU versus a divided dose over five consecutive days. The divided dose schedule provided a slightly higher response rate with significantly less gastrointestinal toxicity than the single dose schedule. However, both regimens yielded