Chemotherapy: No prior chemotherapy for metastatic or recurrent disease. At least 6 months since adjuvant chemotherapy with fluorouracil (5-FU) in combination with levamisole, leucovorin (CF), or IFN-A Interval waived for 5-FU (with or without CF) as a radiosensitizer only . No dose-limiting toxicity with prior 5-FU.