Serum methotrexate (MTX) concentrations and prognosis in patients with osteosarcoma of the extremities treated with a multidrug neoadjuvant regimen

SummaryThe relationship between the serum concentration of methotrexate and the prognosis has been studied in 108 patients with osteosarcoma of the extremities treated from September 1986 to December 1989 at the Chemotherapy Department of Rizzoli Hospital.The protocol of neoadjuvant chemotherapy included high doses of methotrexate (HDMTX) adriamycin, cisplatinum, ifosfamide and VP-16. After a median follow-up of 40.4 months (range 24-62), 84 (77.7%) of the patients studied remained continuously disease-free (CDF) and 24 relapsed. Significantly higher mean serum MTX concentrations were observed in the patients who remained CDF (669.5 μmol/1) than in the patients who relapsed (571.9 μmol/1) ( p < .004). The breaking point of prognostic significance for the serum MTX levels seems to be 700 μmol/1. In fact, according to the mean MTX concentrations, the patients with less than 700 μmol/1 showed a significantly lower disease-free survival than the patients with higher mean MTX concentrations (68.12% vs 94.87% p...