Background: Malignant rhabdoid tumor (MRT) is an aggressive, invariably lethal tumor that is resistant to multimodal therapy.
Methods: The authors reviewed the clinicopathologic features, treatment, and outcome of 13 children (7 boys and 6 girls) with diagnoses of primary extracranial MRT at St. Jude Children's Research Hospital between 1981 and 1990.
Results: The median age at diagnosis was 8 months (range, 10 weeks-18 years). Primary sites included the kidney (seven patients), liver (three patients), soft tissue of scapula, posterior mediastinum, and retroperitoneum. Seven patients had metastatic disease (lungs, six patients; cutaneous hemangioma, one patient). Ten patients had surgical resection of primary tumor (complete, nine patients; incomplete, one patient). Eleven patients had chemotherapy with multiple agents. Three of four chemotherapy responses observed were with regimens containing ifosfamide. Partial responses (PR, > 50% reduction in tumor size) were obtained in one patient who received single-agent ifosfamide during disease relapse (PR lasting 2 months), one patient who received a combination of ifosfamide, carboplatin, and etoposide at diagnosis (PR lasting 5 months), and one patient who was treated with bleomycin, cyclophosphamide, doxorubicin, and vincristine at diagnosis (PR lasting 5 months) and subsequently with ifosfamide in combination with carboplatin and etoposide during disease relapse (PR lasting 4 months). All patients died at a median period of 5 months (range, 0.5-30 months) after diagnosis.
Conclusions: Based on this review, the authors recommend using ifosfamide alone or in combination with carboplatin and etoposide in front-line therapy for malignant rhabdoid tumor.