OUTLINE: This is a dose escalation study. Patients receive oxaliplatin IV over 120 minutes, immediately followed by irinotecan IV over 30 minutes, weekly for 4 weeks (days 1, 8, 15, and 22). Courses are repeated every 42 days. Treatment continues in the absence of unacceptable side effects or disease progression. Sequential dose escalation of oxaliplatin is followed by sequential dose escalation of irinotecan. Dose escalation in cohorts of 3-6 patients each continues until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose limiting toxic effects. Patients are followed approximately every 2-3 months.