OUTLINE: This is a randomized, multicenter study. Patients are stratified according to participating center, WHO performance status (0 or 1 vs 2), and disease stage (metastatic vs locally advanced). Patients are randomized to 1 of 3 treatment arms. Arm I: Patients receive fluorouracil (5-FU) IV over 24 hours weekly for 6 weeks. Arm II: Patients receive leucovorin calcium (CF) IV over 2 hours followed by 5-FU IV over 24 hours weekly for 6 weeks. Arm III: Patients receive CF and 5-FU as in arm II and cisplatin IV over 1 hour on days 1, 15, and 29. Treatment repeats every 7 weeks for a maximum of 4 courses in the absence of unacceptable toxicity or disease progression. Patients are followed every 8 weeks.