Postradiation soft tissue sarcoma: a multiinstitutional analysis of 14 cases in Japan

Radiation therapy (RT) is commonly used to treat malignant tumors, but it leads to side effects and complications. Postradiation sarcomas developing from a previously irradiated area are especially vicious to deal with, though their occurrence is rare. This article focuses on the clinical manifestations, pathological characteristics, and therapeutic effects concerning postradiation soft tissue sarcomas (PRSTSs). A series of 14 PRSTSs treated between 1979 and 2000 in five hospitals in Japan were analyzed. Their histological types were malignant fibrous histiocytoma (eight cases), extraskeletal osteosarcoma (four cases), fibrosarcoma (one case), and leiomyosarcoma (one case). The primary diagnoses, RT history, latent period, and outcome of treatment were studied retrospectively. The original tumors included uterine cancer (seven cases), breast cancer (four cases), synovial sarcoma (one case), squamous cell carcinoma (one case), and Hodgkin’s disease (one case). There were 13 women and 1 man, with ages ranging from 23 to 77 years (mean 58 years) at the time of the appearance of the PRSTS. RT doses ranged from 48 to 91Gy (mean 62Gy). The latent period from RT to the occurrence of the PRSTS varied from 4 to 27 years (mean 12.6 years). Altogether, 4 of 13 patients (31%) had recurrence of the sarcoma after resection. Of the 10 patients whose tumors were removed with a wide margin, one had a local recurrence; 3 cases were performed with a marginal margin and all 3 had a local recurrence. One of three who underwent RT and one of five who underwent chemotherapy (CT) responded. Of the 14 patients, 6 (42.9 %) survived continuously disease free, 2 (14.3%) died from other causes, 2 (14.3%) has an unknown outcome, and 4 (28.6 %) died of the disease during the follow-up period of 16–36 months (mean 24 months). The deaths due to other causes included an esophageal cancer and a wound infection. The prognosis of the PRSTS patients was not poor if the tumor could be removed with a wide surgical margin. Because adjuvant therapies including RT and CT had a poor effect on PRSTSs, the primary treatment of PRSTSs should be radical resection with a wide margin.