Levamisole adds granulocyte toxicity to 5FU-based chemotherapies in adjuvant treatment of Dukes B-C colorectal cancer. A preliminary report.
41 patients (pilot study-I) and 50 patients (multicenter study II) were randomized to receive as systemic chemotherapy for 6 courses with 5 FU alone (A) [440 (I)-450 (II) mg/m2 IV bolus, 5/21 days] or folinic acid followed by 5 FU (B) (respectively 200 and 370 mg/m2 IV bolus, 5/21 days). In the multicenter trial, oral levamisole at the dose of 150 mg/day (3/14 days) was added to chemotherapy for one year. Ten patients in study I and 19 patients in study II also received a post-operative course of intra-portal chemotherapy. Toxicity was evaluated respectively on 232 (I) and 276 (II) courses. Clinical limiting toxicities were stomatitis and diarrhea. In protocol II, a significant enhancement of grades 3-4 granulocyte toxicity was seen (17.3% of courses in II vs only 3.4% in I; p < 0.001). This was especially recorded in the group treated with 5-FU alone (26% of courses in A vs 11% in B; p < 0.001). Levamisole was therefore stopped in 12 cases (10 cases in A; 2 cases in B).