Criteria for Using Intraperitoneal (IP) Chemotherapy for Advanced Ovarian Cancer

Abstract

Ovarian cancer is a disease that remains confined to the abdominal cavity in the majority of cases. IP therapy, therefore, offers an attractive treatment strategy for providing high concentrations of drugs directly to tumor sites. The size of any remaining tumor nodules at the initiation of chemotherapy is the most critical factor in selecting patients who may benefit from IP therapy. It has been demonstrated that chemotherapeutic agents can penetrate into tumor nodules approximately 1–2 mm from the surface. Then, theoretically, IP therapy should only benefit patients with very small residual disease at the initiation of therapy or it must be combined with intravenous therapy that can reach the center of tumor nodules. Los et al. [1] used an IP rat model to demonstrate that the concentration of cisplatin was higher in the periphery of tumor nodules following IP administration, while the concentration in the center was equivalent to that of intravenously (IV) administered cisplatin. By convention, optimal residual disease is defined as no individual tumor mass greater than 1 cm in diameter. Most recent trials of IP therapy include this definition as part of their eligibility criteria. Whether or not patients with larger disease at the initiation of IP therapy may also benefit from IP therapy is controversial. GOG 104, a randomized trial of IV cyclophophamide plus IP cipslatin vs. IV cylophosphamide plus IP cisplatin [2], permitted accrual of women with residual disease up to 2 cm in diameter. The effect of the treatment route (IV vs. IP) was not influenced by the size of the residual disease (microscopic vs. #0.5 cm vs. > 0.5–2 cm). Although it is possible that women with suboptimal disease may benefit from IP therapy, the majority of randomized trials that have demonstrated a benefit to IP therapy have included patients with optimal residual disease [3, 4].