Etoposide and carboplatin: a highly effective combination in relapsed or refractory Wilms' tumor--a phase II study by the French Society of Pediatric Oncology.

PURPOSE: Since we had previously demonstrated encouraging efficacy of etoposide in patients with relapsed or refractory Wilms' tumor (WT), the likely synergism between etoposide and platinum compounds prompted us to conduct a phase II study of a combination with carboplatin. PATIENTS AND METHODS: Twenty-six relapsed or refractory WT patients were included in a phase II study of two courses of combination etoposide 100 mg/m2/d for 5 days and carboplatin 160 mg/m2/d for 5 days, with a 21-day interval between the two courses. Initial stages were I (n = 2), II (n = 8), III (n = 6), IV (n = 6), V (n = 3), and unknown (n = 1). Sites of diseases were lung(s) (11 patients), abdomen-pelvis or liver or primary tumor (six patients), and multiple (eight patients). Histology was unfavorable in three of 26 patients.
RESULTS: Complete response (CR) was documented in eight patients and partial remission (PR) in 11 (overall response rate, 73%). Stable disease (SD) was observed in five patients and progressive disease (PD) in two. Thrombocytopenia (grade IV) was the major toxicity, and platelet transfusions were required in all but two patients. Grade III anemia and grade III to IV neutropenia were seen in 19 and 23, respectively, of 25 assessable first courses. Venoocclusive disease of the liver was fatal in one child who had undergone irradiation to the whole abdomen, 8 weeks before study.
CONCLUSION: Combination etoposide and carboplatin has impressive activity in refractory or relapsed WT at the cost of high-grade hematologic toxicity, especially thrombocytopenia. It is of great interest in second-line therapy, since eight of 26 patients are still alive in continuous CR (median follow-up duration, 40 months; range, 24 to 56). This combination deserves further investigation as first-line or consolidation treatment.