Strong L C, Herson J, Osborne B M, Sutow W W
J Natl Cancer Inst. 1979 Jun;62(6):1401-6.
Twenty-four long-term survivors of Ewing's sarcoma were identified as being at risk for a second primary tumor. Among this group of patients followed from 3 to 22 years, 4 new bone tumors were observed, whereas 1.2 x 10(-3) were expected. All new tumors arose in heavily irradiated areas. The risk associated with radiation after 3 years was 7.2 cases/million person-years per rad. The cumulative cancer risk over 10 years for irradiated patients was 35% (SE, 15.1%). Intensive chemotherapy (cyclophosphamide and vincristine administered in five or more courses) seemed to exert an enhancing effect, increasing the rate of development of new tumors.
24名尤因肉瘤长期幸存者被确定有发生第二原发性肿瘤的风险。在这群随访3至22年的患者中，观察到4例新发骨肿瘤，而预期为1.2×10(-3)例。所有新肿瘤均发生在高剂量辐射区域。3年后与辐射相关的风险为每拉德7.2例/百万人年。接受辐射患者10年的累积癌症风险为35%（标准误，15.1%）。强化化疗（环磷酰胺和长春新碱应用五个或更多疗程）似乎有增强作用，增加了新肿瘤的发生速率。
