IFOSFAMIDE TREATMENT OF RECURRENT OR METASTATIC ENDOMETRIAL STROMAL SARCOMAS PREVIOUSLY UNEXPOSED TO CHEMOTHERAPY - A STUDY OF THE GYNECOLOGIC-ONCOLOGY-GROUP

Objective: To determine the effectiveness and toxicity of ifosfamide c hemotherapy in women with metastatic or recurrent endometrial stromal sarcomas unexposed to other chemotherapy. Methods: In a prospective, m ulti-institutional phase II study conducted by the Gynecologic Oncolog y Group, the starting dose of ifosfamide was 1.5 g/m(2) given daily in travenously (IV) for 5 days (reduced to 1.2 g/m(2) daily in patients w ho had previously received radiotherapy). Mesna (2-mercaptoethane sodi um sulfonate) was given IV immediately and at 4 and 8 hours after the administration of ifosfamide. Each dose of mesna was 20% of the total daily dose of ifosfamide. Patients were treated every 3 weeks if blood counts permitted. Therapy was discontinued if there was progression o f the cancer or unacceptable toxicity. Results: Twenty-two patients we re entered into this study. One was excluded from analysis because of the wrong histologic type, leaving 21 evaluable for response and toxic ity. Gynecologic Oncology Group grade 3 or 4 granulocytopenia occurred in four patients (19%), and one patient each experienced Gynecologic Oncology Group grade 4 anemia and genitourinary toxicity. Three patien ts experienced complete tumor responses and four had partial responses , for an overall response rate of 33.3%. Conclusion: Ifosfamide is act ive in the therapy of women with chemotherapy-naive metastatic or recu rrent endometrial stromal sarcomas.