Intraperitoneal α-Interferon Alternating with Cisplatin in Residual Ovarian Carcinoma: A Phase II Gynecologic Oncology Group Study

Objective. The aim of this study was to study the combination of intraperitoneal α-interferon and cisplatin administered second-line in an alternating sequence in small volume residual epithelial ovarian cancer after second-look surgery and the activity of this combination based on prior response to first-line platinum compounds. Methods. Sixty-two patients with minimal residual (<0.5 cm) epithelial ovarian cancer at reassessment laparotomy were entered into a multicenter trial of intraperitoneal α-interferon alternating with cisplatin given for eight cycles unless disease progression or unacceptable toxicity occurred. The patients were considered favorable if they were platinum-sensitive and/or relapsed 6 months or longer after completing treatment. Another reassessment laparotomy was performed within 12 weeks of completion of treatment in patients who were in clinical remission. Results. Fifty-four patients were clinically evaluable and 18 were surgically reassessed, 5 of whom had a negative reassessment operation (20% complete response and 8% partial response). Of the 54 patients evaluable for toxicity, the most common adverse effects of more than grade 2 were gastrointestinal in 13 (47%), neutropenia in 9 (17%), and leukopenia in 6 (12%). Grade 4 toxicity was seen in 10 instances: 4 gastrointestinal, 2 neutropenia, 2 thrombocytopenia, 1 wound infection, and 1 allergic reaction. Conclusions. α-Interferon and cisplatin are active agents in favorable patients with minimal residual epithelial ovarian cancer at second-look. The combination of the two drugs administered in an alternating sequence appears to be associated with more side effects than when either drug is administered alone. The combination produced response rates similar to those seen when either drug is given alone.