OUTLINE: This is a multicenter study. Patients receive 4 courses of oxaliplatin IV and leucovorin calcium IV over 2 hours on day 1 followed by fluorouracil IV continuously over 46 hours. Following the initial 4 courses of therapy, patients receive 4 courses of irinotecan IV over 30-90 minutes and leucovorin calcium IV over 2 hours on day 1 followed by fluorouracil IV continuously over 46 hours. Courses repeat every 2 weeks in the absence of disease progression or unacceptable toxicity. Quality of life is assessed every 8 weeks. Patients are followed every 3 months until death.