OUTLINE: Patients receive gemcitabine IV over 30 minutes followed by leucovorin calcium IV and fluorouracil IV over 5-10 minutes on days 1, 8, and 15. Treatment repeats every 4 weeks for a minimum of 2 courses in the absence of disease progression or unacceptable toxicity. Patients are followed every 3 months for 1 year and then every 6 months for 4 years.