Hyperthermic Intraperitoneal Chemotherapy (HIPEC): An Overview of the Molecular and Cellular Mechanisms of Actions and Effects on Epithelial Ovarian Cancers.

Most patients with epithelial ovarian cancers (EOCs) are at advanced stages (stage III-IV), for which the recurrence rate is high and the 5-year survival rate is low. The most effective treatment for advanced diseases involves a debulking surgery followed by adjuvant intravenous chemotherapy with carboplatin and paclitaxel. Nevertheless, systemic treatment with intravenous chemotherapeutic agents for peritoneal metastasis appears to be less effective due to the poor blood supply to the peritoneal surface with low drug penetration into tumor nodules. Based on this reason, hyperthermic intraperitoneal chemotherapy (HIPEC) emerges as a new therapeutic alternative. By convection and diffusion, the hyperthermic chemotherapeutic agents can directly contact intraperitoneal tumors and produce cytotoxicity. In a two-compartment model, the peritoneal-plasma barrier blocks the leakage of chemotherapeutic agents from peritoneal cavity and tumor tissues to local vessels, thus maintaining a higher concentration of chemotherapeutic agents within the tumor tissues to facilitate tumor apoptosis and a lower concentration of chemotherapeutic agents within the local vessels to decrease systemic toxicity. In this review, we discuss the molecular and cellular mechanisms of HIPEC actions and the effects on EOCs, including the progression-free survival (PFS), disease-free survival (DFS) and overall survival (OS). For primary advanced ovarian cancers, more studies are agreeing that patients undergoing HIPEC have better surgical and clinical (PFS; OS) outcomes than those not, although one study reported no differences in the PFS and OS. For recurrent ovarian cancers, studies have revealed better DFS and OS in patients undergoing HIPEC than those in patients not undergoing HIPEC, although one study reported no differences in the PFS. HIPEC appears comparable to traditional intravenous chemotherapy in treating advanced EOCs. Overall, HIPEC has demonstrated some therapeutic benefits in many randomized phase III trials when combined with the standard cytoreductive surgeries for advanced EOCs. Nevertheless, many unknown aspects of HIPEC, including detailed mechanisms of actions, along with the effectiveness and safety for the treatment of EOCs, warrant further investigation.