Control of primary osteosarcoma with chemotherapy

High‐dose methotrexate with citrovorum factor “rescue” (MTX‐CF) produced an apparent complete response of the primary tumor in three patients with osteosarcoma. The response was sustained with MTX‐CF, intra‐arterial cis‐diamminedichloroplatinum II (CDP) and Adriamycin (doxorubicin) for 18 months. Treatment was then electively discontinued. Local recurrence occurred in two patients, 6 and 4 months later, respectively. MTX‐CF was reinstated and a complete response was again achieved in one patient. This has been maintained for 15+ months with MTX‐CF and intra‐arterial CDP administered for 13 of the 15+ months. Reinduction with MTX‐CF failed in the second relapsed patient but an apparent remission was again achieved with radiation and intra‐arterial CDP. This has been maintained with intravenous CDP, cyclophosphamide and phenylalanine mustard for 14+ months. A complete response in the primary tumor was still present in the nonrelapsed patient, 42 months from diagnosis. All patients have remained free of pulmonary metastases, 40+ to 42+ months from diagnosis.