[Neo-adjuvant therapy in childhood osteogenic sarcoma: a pilot study of selective postoperative chemotherapy based on response to preoperative high-dose methotrexate].

"Neo-adjuvant therapy" with preoperative high-dose methotrexate (HD-MTX) and CF rescue therapy was investigated in four children with osteogenic sarcoma. Immediately after the diagnosis of osteogenic sarcoma from biopsy, the patients were treated with three to five courses of weekly HD-MTX (300 mg/kg) with CF rescue. Three patients had en bloc tumor resection and one patient underwent disarticulation of the hip joint after the pre-operative HD-MTX. The effect of HD-MTX was evaluated on the basis of pathological changes between the specimen of the primary tumor taken at biopsy and that during surgery. Two out of four patients showed marked tumor cell reduction (greater than 50%) of the specimen upon surgery. Two patients who responded to the preoperative HD-MTX were further treated with HD-MTX on a post-operative adjuvant therapy basis for 18 months. Both of these patients survived with no evidence of disease for 35.6+ and 20.9+ months. Two patients who responded poorly to HD-MTX were treated with a multi-drug postoperative adjuvant therapy including cis-platinum, adriamycin, cyclophosphamide, actinomycin D, and bleomycin. One patient had a solitary lung metastasis at 12.2 months after amputation. Wedge resection of the metastatic tumor was performed and adjuvant therapy with cis-platimum has been given for 20 months. He has remained with no evidence of disease for more than 30 months. Another patient has been receiving multi-drug neo-adjuvant therapy without any evidence of disease for 11.9 months after surgery. These data suggest that neo-adjuvant chemotherapy based on the response to preoperative HD-MTX is more useful for increasing the cure rate of childhood osteogenic sarcoma.