Intraperitoneal administration of interferon gamma. An efficient adjuvant to the chemotherapy of ovarian cancers. Apropos of an European study of 108 patients

One hundred and eight patients with residual epithelial ovarian cancer at second laparotomy, after first line plastine-based chemotherapy were treated with intraperitoneal rHU-interferon-gamma at a dose of 20 x 10(6) U/m2, twice a week for 3-4 months. 86% of the patients had residual macroscopic tumors and 33% bulky tumors (> 2 cm). From the 99 evaluable patients, 62 had an evaluative third laparotomy and nine additional patients a laparotomy. Complete pathologic and global response rates to interferon-gamma were 23 and 32% respectively. Age and tumor size were independently correlated with treatment response. Patients (n = 41) under the age of 60 with a tumor size less than 2 cm had a complete and global response rate of 42 and 54% respectively. Interferon-gamma was equally effective in chemo-resistant and chemosensitive tumors. Median duration of response was 21 months and median survival of responder patients was 86% at 2 years. In multivariate analysis, response to interferon-gamma was the most prominent prognostic factor of this population of patients with residual ovarian cancer.