OUTLINE: This is a dose escalation study. Patients receive oral topotecan daily on days 1-5 and oral etoposide daily on days 8-10. Courses repeat every 28 days in the absence of disease progression or unacceptable side effects. Patients achieving partial or complete response or stable disease continue treatment for at least 4-6 courses. Cohorts of 3-6 patients receive topotecan and etoposide on increasing numbers of days until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which no greater than 1 of 6 patients experiences dose limiting toxicity. Patients are followed every 3 months or until death.