A controlled pilot study of high-dose methotrexate as postsurgical adjuvant treatment for primary osteosarcoma.

Thirty-eight patients whose primary extremity or limb girdle osteosarcomas had been completely excised (37 amputations, one limb sparing procedure) were allocated at random to two treatment groups receiving respectively regular follow-up examinations plus a high-dose methotrexate (HDMTX) regimen or regular follow-up without primary adjuvant chemotherapy. Although the vincristine, HDMTX, leucovorin regimen was generally quite tolerable when given at three-week intervals for one year and most of the chemotherapy patients followed the planned HDMTX dose escalations from 3 to 6 to 7.5 g/m2, delayed methotrexate excretion limited dosage escalations in 25%. An estimated 52% of the 38 patients were surviving five years after randomization and an estimated 42% remained continuously relapse-free after five years. No significant differences between the outcomes of the 20 treated and the 18 untreated patients were apparent; however, power to detect differences was low. Furthermore, no significant differences in postmetastasis survival were apparent between the 12 treated and 10 untreated patients who relapsed. Approximately 20% of these failing patients appear to have been salvaged for long-term survival. This pilot study of HDMTX confirms the continuing need for controlled clinical trials in determining the therapeutic value of adjuvant chemotherapy programs for patients with primary osteosarcoma.