Histologic response of high-grade nonmetastatic osteosarcoma of the extremity to chemotherapy

In 510 patients with osteosarcoma of the extremity treated at the authors' institute between March 1983 and June 1995 with different regimens of neoad juvant chemotherapy, factors that influenced the histologic response were i nvestigated. The rate of total necrosis was not related to the patients' ge nder, age, site, size of tumor, serum of alkaline phosphatase values, or ro ute of cisplatin administration. The histologic response significantly and independently correlated with the number of drugs administered before surge ry and with the histologic subtype of the tumor. According to the number of drugs used, the percentage of total necrosis was 31% for a four-drug regim en, 18% for a three-drug regimen, and only 1.5% for a two-drug regimen. Acc ording to the histologic type, the rates of total necrosis were 41% for tel angiectatic tumors, 36% for fibroblastic tumors, 15% for osteoblastic tumor s, and 3% for chondroblastic tumors. The authors concluded that in neoadjuv ant therapy of osteosarcoma, the histologic response to preoperative treatm ent, which correlates with prognosis, depends on the effectiveness of the c hemotherapy regimen and on some features intrinsically inherent to the tumo r. These data should be considered when selecting the type of treatment (ad juvant or neoadjuvant) and the combinations of drugs to be used in preopera tive treatment of patients with osteosarcoma.