SYNOVIAL SARCOMA - UNIFORM RESPONSE OF METASTASES TO HIGH-DOSE IFOSFAMIDE

Background. This report describes the unusually high response rate of metastatic synovial sarcoma to high dose ifosfamide (14-18 g/m(2)) whe n that drug was used to treat 13 consecutive patients with recurrent m etastatic synovial sarcoma before surgery (or thoracotomies) to provid e optimal salvage therapy for these patients. Patients and Methods. Th irteen patients with recurrent or pulmonary metastatic synovial sarcom a seen at the Cedars-Sinai Comprehensive Cancer Center (Los Angeles, C A) from April, 1989 through January, 1993 were treated with high dose ifosfamide (14-18 g/m(2)). Ifosfamide was infused at the dose of 2 g/m (2) over a 4-hour bolus infusion, followed by 2-g/m(2) 24-hour continu ous infusions of ifosfamide, for a total of 14 or 18 g/m(2) (6-8 days) . Mesna (Mesnex, Bristol-Myers Oncology, Princeton, NT) was infused wi th the ifosfamide at equimolar doses. Supplemental sodium bicarbonate (180 mEq) was given daily to prevent severe acidosis. Nine of the thir teen patients were treated with prior chemotherapy for their primary t umors. Prior chemotherapy consisted of doxorubicin (Adriamycin, Adria Labs, Dublin, OH) in all patients and doxorubicin combined with cispla tin in eight of them. Results. All 13 patients had objective responses to high dose ifosfamide chemotherapy. There were nine partial respons es and four complete responses. Five of the patients died of disease a t 20-40 months (median, 27 months) from initial therapy. Eight patient s have survived from 2 to 43 months (median, 20 months) from initial t herapy, and three of these patients are disease free. Those patients s urviving disease free had successful surgical removal of their residua l metastatic disease after chemotherapy. Conclusion. Metastatic synovi al sarcoma appears to be particularly sensitive to high dose ifosfamid e chemotherapy. This experience suggests that there is a role for high dose ifosfamide chemotherapy in preoperative and postoperative adjuva nt chemotherapy for primary synovial sarcoma, which is usually always a high grade malignant lesion with a poor prognosis after surgery alon e.