Intraperitoneal interferon-alpha-2b for patients with no macroscopic disease following second-look laparotomy

Low to intermediate doses of interferon-alpha-2b (10-30 million units every 2 weeks for six cycles), were administered intraperitoneally to 14 patients with no macroscopic disease at the completion of second-look laparotomy. Eight patients had a negative second-look so the treatment was given as consolidation therapy. Five patients had a microscopically positive second-look and one patient had small macroscopic disease completely resected. Toxicity was low. However, four of the eight patients with a negative second-look relapsed (two in the peritoneum) and five of the other six patients have also relapsed, all in the peritoneum. Four of these latter six patients received intraperitoneal cisplatinum in addition to the interferon. Mean time to relapse for the group with a negative second-look was 18 months, while it was 16 months for the group with microscopic residual disease. Median follow-up was 38 months. Intraperitoneal interferon in the dosages given in this trial does not seem to be effective as consolidation therapy, nor is it effective for patients with microscopic residual disease at second-look laparotomy.