Definitive surgery of primary lesion should be prioritized over preoperative chemotherapy to treat high-grade osteosarcoma in patients aged 41-65 years.

BACKGROUND Recently, the number of osteosarcomas in middle-aged and older patients has demonstrated an increasing trend; moreover, their results are comparatively worse than those of young patients. In Europe and the USA, the prognosis for osteosarcoma in middle-aged and older patients has improved with adjuvant chemotherapy. In Japan, however, the prognosis has remained poor. MATERIALS AND METHODS We retrospectively analyzed the outcomes of osteosarcoma, especially in regards to preoperative chemotherapy, from January 1980 to July 2014. A total of 29 patients with high-grade osteosarcoma between the age of 40 and 65 years were included. We included patients without distant metastasis and with primary lesions that were deemed resectable. The mean age was 52.8 years (range 41-65 years), and the mean follow-up period was 103.2 months (range 5-314 months). RESULTS Adjuvant chemotherapy was administered to 27 of 29 patients (93%), and 8 of 15 cases (53%) were able to undergo preoperative chemotherapy as planned, including CDDP. A major complication of chemotherapy was acute kidney injury due to CDDP (26%). The 5-year OS and 5-year EFS were 64.9% and 57.1%, respectively. After 2006, a policy to prioritize the resection of the primary lesion was implemented, and if the primary lesion was deemed resectable, preoperative chemotherapy was either not administered or administered for only a short duration. The 5-year OS after 2006 improved to 78.8%. CONCLUSIONS This study shows that administration of high-dose intensity preoperative chemotherapy was difficult in middle-aged and older patients due to their high rate of acute kidney injury by CDDP. For cases of osteosarcoma in middle-aged and older patients, if the primary lesion is resectable, preoperative chemotherapy should be minimized to prioritize the resection of the primary lesion. It was considered that, with appropriate measures to prevent complications, adjuvant chemotherapy may lead to improved prognosis. LEVEL OF EVIDENCE V.