NO ADVANTAGES IN THE ADDITION OF IFOSFAMIDE AND VP-16 TO THE STANDARD 4-DRUG REGIMEN IN THE MAINTENANCE PHASE OF NEOADJUVANT CHEMOTHERAPY OF EWINGS-SARCOMA OF BONE - RESULTS OF 2 SEQUENTIAL STUDIES

Between January 1988 and December 1990, 74 patients with localized Ewing's sarcoma of bone were treated with a new protocol that consisted of an initial 6-week period of chemotherapy with vincristine (VCR), adriamycin (ADM) and cyclophosphamide (EDX) followed by local therapy and addittional chemotherapy with the same drugs previously indicated plus ifosfamide and VP-16. The rationale for the addition of ifosfamide and VP-16 to the four drugs of the standard chemotherapy of this tumor was that this drug combination was previously very effective in the treatment of metastases from Ewing's sarcoma even in patients who did not respond to cyclophosphamide. As local treatment all patients were offered surgery, when feasible (70 cases). Forty-three patients accepted and 27 refused. These patients, as the 4 patients in whom surgery was not considered feasible, were treated with radiation therapy alone (50-60 Gy). In the remaining patients amputation was performed in 4 cases, rotationplasty in 3 and resection in 36. Where conservative surgery was marginal or intralesional (30 cases), radiotherapy at lower doses (40-45 Gy) was also delivered. At a mean follow-up of 3.5 years (2-7), 43 patients (58%) remained continuously disease-free and 31 relapsed (29 with metastases and 2 with both metastases and local recurrences). These results do not differ from those obtained at our Institution in 98 patients treated between 1983 and 1988 with a neoadjuvant protocol in which only VCR, ADM, EDX and dactinomycin (DAC) were used (3-year continuously disease-free survival (CDFS) respectively of 54% and 55%). Despite the fact that these results came from a non-randomized study, the Authors conclude that the addition of ifosfamide and VP-16 to the four-drug standard regimen did not improve the outcome of the patients with Ewing's sarcoma of bone which remains a lethal disease in about 50% of the cases. These findings stress the need to find more effective chemotherapeutic regimens for the associated treatment of this tumor.