Postirradiation sarcoma. Analysis of a nationwide cancer registry material.

Thirty-three cases of postirradiation sarcoma (PIS) from the files of the Finnish Cancer Registry were analyzed. The most frequent first primary tumors were cancers of the breast (seven cases) and female reproductive organs (13 cases). Five patients had a childhood cancer. The median total radiation dose at the site of the PIS was 3600 cGy (1600 cGy to 11200 cGy). The median interval from start of radiation therapy to detection of PIS was 13.2 years (3.4 to 22.8 years). The PIS was of soft tissue origin in 25 of 33 cases. The most frequent histologic types were osteosarcoma (ten cases, including four extraskeletal tumors), malignant fibrous histiocytoma (ten cases), and fibrosarcoma (six cases). The overall crude 5-year survival rate was 29% (calculated from the start of treatment for PIS), and for patients initially treated with either radical surgery or combined marginal surgery and postoperative irradiation it was 67%. The authors conclude that there is a chance for cure for radically treated patients with postirradiation sarcoma that emphasizes the importance of regular long-term follow-up of cancer patients.