DESMOPLASTIC SMALL ROUND-CELL TUMOR - PROLONGED PROGRESSION-FREE SURVIVAL WITH AGGRESSIVE MULTIMODALITY THERAPY

Purpose: To test intensive alkylator-based therapy in desmoplastic sma ll round-cell tumor (DSRCT). Patients and Methods: Patients received t he P6 protocol, which has seven courses of chemotherapy. Courses 1, 2, 3, and 6 included cyclophosphamide 4,200 mg/m(2), doxorubicin 75 mg/m (2), and vincristine (HD-CAV), Courses 4, 5, and 7 consisted of ifosfa mide 9 g/m(2) and etoposide 500 mg/m(2) for previously untreated patie nts, or ifosfamide 12 g/m(2) and etoposide 1,000 mg/m(2) for previousl y treated patients. Courses started after neutrophil counts reached 50 0/mu L and platelet counts reached 100,000/mu L. Tumor resection was a ttempted. Post-P6 treatment options included radiotherapy and ct myelo ablative regimen of thiotepa (900 mg/m(2)) plus carboplatin (1,500 mg/ m(2)), with stem-cell rescue. Results: Ten previously untreated and tw o previously treated patients have completed therapy The male-to-femal e ratio was 11:1. Ages were 7 to 22 years (median, 14). The largest ma sses were infradiaphragmatic (n = 11) or intrathoracic (n = 1). Other findings included serosal implants (n = 11), regional lymph node invas ion (n = 8), ascites or pleural effusion (n = 7), and metastases to li ver (n = 5), lungs (n = 4), distant lymph nodes (n = 3), spleen (n = 2 ), and skeleton (n = 2). Tumors uniformly responded to HD-CAY, but the re were no complete pathologic responses. One patient died at 1 month from tumor-related Budd-Chiari syndrome. Of seven patients who achieve d a complete remission (CR), five remain in CR 9, 12, 13, 33, and 38 m onths from the start of P6, one patient died of infection at 12 months (autopsy-confirmed CR), and one patient relapsed 4 months off therapy . Of four patients who achieved a partial remission (PR), one remains progression-free at 34 months and three developed progressive disease. Five patients received local radiotherapy: three were not assessable for response, but in two patients, antitumor effect was evident Four p atients received thiotepo/carboplatin: two were in CR and remain so, a nd two patients had measurable disease that did not respond. Conclusio n: For control of DSRCT, our experience supports intensive use of HD-C AV, aggressive surgery to resect visible disease, radiotherapy to high -risk sites, and myeloablative chemotherapy with stem-cell rescue in s elected cases. (C) 1996 by American Society of Clinical Oncology.