OUTLINE: This is a dose escalation, multicenter study of capecitabine. Patients are stratified by pretreatment status (any pretreatment vs chemotherapy naive vs thymidylate synthase inhibitor pretreatment). Phase I : Patients receive oxaliplatin IV over 2 hours on day 1 and oral capecitabine every 12 hours on days 1-14. Treatment repeats every 3 weeks in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of capecitabine until the maximum tolerated dose (MTD) is determined. The MTD is defined as the highest dose at which 2 or more of 6 patients experience dose limiting toxicity. Phase II: Patients receive capecitabine at the feasible dose. The feasible dose is defined as the dose immediately preceding the MTD from phase I. Patients are followed every 3 months for 1 year, and then every 6 months thereafter until death.