Second malignancies after treatment for Ewing's sarcoma: a report of the CESS-studies.

PURPOSE: During recent years, more intensified systemic and local treatment regimens have increased the 5-year survival figures in localized Ewing's sarcoma to more than 60%. There is, however, concern about the risk of second malignancies (SM) in long-term survivors. We have analyzed the second malignancies in patients treated in the German Ewing's Sarcoma Studies CESS 81 and CESS 86.

MATERIALS AND METHODS: From January 1981 through June 1991, 674 patients were registered in the two sequential multicentric Ewing's sarcoma trials CESS 81 (recruitment period 1981-1985) and CESS 86 (1986-1991). The systemic treatment in both studies consisted of a four-drug-regimen (VACA = vincristine, actinomycin D, cyclophosphamide, and adriamycin; or VAIA = vincristine, actinomycin D, ifosfamide, and adriamycin) and a total number of four courses, each lasting nine weeks, was recommended by the protocol. Local therapy in curative patients was either complete surgery (n = 162), surgery plus postoperative radiotherapy with 36-46Gy (n = 274), or definitive radiotherapy with 46-60Gy (n = 212). The median follow-up at the time of this analysis was 5.1 years, the maximum follow-up 16.5 years.

RESULTS: The overall survival of all patients including metastatic patients was 55% after 5 years, 48% after 10 years, and 37% after 15 years. Eight out of 674 patients (1.2%) developed a SM. Five of these were acute myelogenic leukemias (n = 4) or MDS (n = 1), and three were sarcomas. The interval between diagnosis of Ewing's sarcoma and the diagnosis of the SM was 17-78 months for the four AMLs, 96 months for the MDS and 82-136 months for the three sarcomas. The cumulative risk of an SM was 0.7% after 5 years, 2.9% after 10 years, and 4.7% after 15 years. Out of five patients with AML/MDS, three died of rapid AML-progression, and two are living with disease. Local therapy (surgery vs. surgery plus postoperative irradiation vs. definitive radiotherapy) had no impact on the frequency of AML/MDS, but local therapy did influence the risk of secondary sarcomas. All three patients with secondary sarcomas had received radiotherapy; however, all three sarcomas were salvaged by subsequent treatment and are in clinical remission with a follow-up of 1 month, 4.3 years, and 7.5 years after the diagnosis of the secondary sarcoma. Thus far, SM contributed to less than 1 % (3/328) of all deaths in the CESS-studies.

CONCLUSIONS: The risk of leukemia after treatment for Ewing's sarcoma is probably in the range of 2%. The risk of solid tumors also seems to be low within the first 10 years after treatment and remains in the range of 5 % after 15 years. In the CESS-studies, less than 1% of all deaths within the first 10 years after diagnosis were caused by SM. Effective salvage therapy for secondary sarcomas is feasible.