Long-lasting multiagent chemotherapy in adult high-risk Ewing's sarcoma of bone.

The outcome of Ewing's sarcoma depends on the anatomical site of the tumor. Studies conducted in high-risk patients are limited. We evaluated the outcome of high-risk Ewing's sarcoma patients that received long-term treatment protocol. Twenty-five patients (22 males, 3 females) with poor prognostic features were treated according to long-term Ewing's sarcoma protocol. Central-axis localization, inadequacy or unavailability of surgical resection, older than 15 years of age, are accepted as high-risk factors. The median age of patients was 23 years (range, 18-55). The tumor localization was pelvis (9), femur (1), tibia (1), fibula (1), maxilla (1), clavicle (1), vertebrae (5), metatarse (1), and ribs (5). Neoadjuvant chemotherapy was applied between weeks 0 and 6, local therapy on week 9, and adjuvant maintenance chemotherapy between weeks 11 and 41. All patients received neoadjuvant and adjuvant maintenance chemotherapy. Local therapy consisted of radiotherapy (32%), surgery alone (12%), or surgery and radiotherapy (56%). The median total treatment period was 10 months. The median follow-up was 25 months (range, 7-89). Three-year cumulative OS and DFS rates were 43% (95% CI, 28.5-57.85) and 40% (95% CI 23.63-52.19), respectively. The most common grade III/IV toxicities observed during the treatment protocol were neutropenia (16%) and gastrointestinal toxicities (16%). Our study indicated that long-term multiagent combination chemotherapy may result in better outcome in adult high-risk patients undergoing adequate surgical resection of the tumor and local radiotherapy. Further randomized studies are needed to assess the efficacy of this treatment protocol in patients with adequate surgical margins.