Intraperitoneal recombinant interferon gamma in ovarian cancer patients with residual disease at second-look laparotomy.

PURPOSE: The purpose of this study was to evaluate the efficacy and tolerance of recombinant human interferon gamma (rIFN-gamma) as second-line treatment in patients with persistent disease at second-look laparotomy. PATIENTS AND METHODS: One hundred eight patients with residual disease at second-look laparotomy were treated with rIFN-gamma (20 x 10(6) IU/m2) administered intraperitoneally (IP) twice a week for 3 to 4 months. In the absence of clinically assessable disease, response to rIFN-gamma was assessed with a third-look laparotomy. RESULTS: Of 98 assessable patients, 31 (32%) achieved a surgically documented response, including 23 patients (23%) with a complete response (CR). The age and size of residual tumor were significant prognostic factors for the response to rIFN-gamma. A 41% CR rate was observed in 41 patients younger than 60 years and with residual tumor less than 2 cm. The probability of response was independent of previous response to first-line chemotherapy. The median duration of response was 20 months and the 3-year survival rate in responders was 62%. Response to rIFN-gamma was the most significant prognostic factor for survival of patients with residual disease. Adverse events included fever, flu-like syndrome, neutropenia, and liver enzyme disturbances. No significant peritoneal fibrosis was noted. CONCLUSION: These results support the potential interest of IP rIFN-gamma as adjuvant treatment in ovarian cancer. Controlled prospective trials are required to determine its place in the therapeutic strategy of this malignancy.