Pathological responses to preoperative high-dose methotrexate chemotherapy in osteosarcoma--experience in Korea cancer hospital.

During the last decade, many clinical investigators at various cancer centers have reported the efficacy of various chemotherapeutic agents in the treatment of osteosarcoma. The regimens using high-dose methotrexate (HDMTX) with citrovorum factor rescue are now considered to be one of the most effective treatments of choice. From December 1989 to May 1991, sixteen patients with Enneking's stage (Enneking et al., 1980) IIB osteosarcoma of the extremities were treated with a high-dose methotrexate regimen. After two cycles of preoperative chemotherapy, an operation was performed; either limb salvage or amputation. The resected lesions were examined pathologically and classified according to Huvos' criteria. On pathological examination, 8 (50%) cases showed Grade IV; 1 (6.25%) Grade III; 4 (25%) Grade II; and 3 (18.75%) Grade I. The types of surgery performed were tumor prosthesis replacement (11); wide resection with or without reconstruction (2); resection and arthrodesis (1); and amputation (2).