Higher-risk tumors are those where there is bowel wall perforation, involvement of adjacent structures and abnormal chromosomes (an aneuploid tumor).
Current adjuvant chemotherapy programs include 5-FU + leucovorin or 5-FU + levamisole . The side effects of treatment with 5-FU + levamisole are few and are primarily associated with 5-FU. Levamisole alone has mild toxicity, mainly gastrointestinal, causing nausea, vomiting, diarrhea or upset stomach, as well as neurotoxicity . Alcohol is to be avoided, as levamisole has an Antabuse-like effect. 5-FU + leucovorin may cause severe diarrhea without low white blood cell counts, and fluids may have to be replaced intravenously in the hospital because of dehydration.
