Levamisole and 5-fluorouracil therapy for resected colon cancer: a new indication

To evaluate the benefits and risks of postoperative treatment with levamisole plus 5-fluorouracil (5-FU) in patients with colon cancer.

Computerized searches of MEDLINE and CANCERLIT were performed, and the reference list of each retrieved article was checked. Only randomized trials of therapy with levamisole alone or combined with 5-FU for colon cancer without distant metastases were included. The studies were then evaluated with the use of four criteria.

We reviewed six randomized trials, of which three satisfied our criteria. Two studies demonstrated a significant improvement in the survival rate with levamisole plus 5-FU among patients with colon cancer and pathologically confirmed metastases to adjacent lymph nodes (Dukes' stage C). A subgroup analysis in another study demonstrated a similar benefit. The toxic effects of the drugs were generally mild. The three other studies showed no difference in survival rates between the treatment groups; however, the samples were too small to detect a clinically or statistically important difference.

Because many patients with colon cancer will suffer a relapse we recommend that they be offered the opportunity to participate in clinical trials of adjuvant therapy. For those with stage C disease not entering a clinical trial levamisole plus 5-FU is appropriate adjuvant therapy.