Evaluation of a standardized protocol of intracavitary recombinant interferon alpha-2b in the palliative treatment of malignant peritoneal effusions - A prospective pilot study

Objective. Several schedules with variable doses of intracavitary interfero n have been proposed for the management of metastatic peritoneal effusions. This prospective pilot study evaluated the efficacy of a standardized sche dule of intraperitoneal interferon alpha (2b-) Methods. In 41 cancer patien ts with malignant ascites a 9-french intraperitoneal catheter was placed un der sonograph,ic guidance, and ascites was drained until abdominal ultrasou nd showed complete absence of effusion. Interferon alpha (2b), 6 or 9 milli on units (body weight less than or equal to or > 50 kg, respectively), was then administered via the tube, which was clamped for 6 h. 6 courses were g iven at 4-day intervals. In comparison with pretreatment levels, the 30-day response was classified as complete (CR) = no fluid recurrence, partial (P R) = fluid recurrence <50% and no response (NR) = >50%. Responders were mon itored until fluid recurrence requiring paracentesis. Results: 12 patients had CR, 15 PR, 14 NR. Global response (GR) was 65.9%. In ovarian cancer, GR was 75% and was not influenced by the quantity of the pretreatment daily f luid production. In the other cancers, a pretreatment fluid production less than or equal to 500 ml/day was associated with a significantly higher res ponse (p<0.05). Patients not showing response within the first 3 courses di d not respond after the next courses. 60-day GR was 41.5%, 90-day GR was 26 .8%. The mean time to fluid reaccumulation was 70.5<plus/minus>75.3 versus 11.4 +/-4.4 days before treatment (p<0.001). The survival of responders was 38-394 days (mean 131), and the average duration of response was 101 days. Conclusion:This protocol could be reasonably applied to ovarian cancer pat ients and to patients with other cancers having a fluid production of <less than or equal to> 500 ml/day, and it should be stopped if no response is o bserved after 3 courses of treatment. Introduction Copyright (C) 2001 S. Ka rger AG, Basel.