OUTLINE: This is a dose escalation, multicenter study. Patients are stratified according to pretreatment (pretreated vs less heavily pretreated). Patients receive ecteinascidin 743 IV over 3 hours on day 1. Treatment continues every 3 weeks in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of ecteinascidin 743 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicities.