OUTLINE: Patients receive topotecan IV over 30 minutes daily for 5 days. Treatment repeats every 3 weeks for a minimum of 1 course in the absence of disease progression or unacceptable toxicity. Patients with complete response, partial response, or stable disease continue treatment for at least three courses. Patients are followed every 4 months for 2 years, every 6 months for 3 years, and then periodically thereafter until death.