Management of peritoneal metastases - Basic concepts

Despite the fact that cytoreductive surgery (CRS) and hyperthermic perioperative chemotherapy (HIPEC) is conceptually simplistic, optimal implementation of this combined treatment remains complex. Multiple patient-related variables, methodologic variables, and pharmacologic variables need to be considered in devising an optimal treatment strategy. Working through these variables considering the pathophysiology of peritoneal metastases and their possible treatments is more likely to provide guidance in terms of successful management than multiple randomized controlled trials. The principles of management include: 1) A surgical technology involving peritonectomy procedures and visceral resections that will result in a complete cytoreduction. 2) Treatment of patients at a maximal low peritoneal cancer index (PCI) will maximize the benefits especially in those patients who have high grade peritoneal metastases from gastric cancer, colorectal cancer, or ovarian malignancy. 3) Tumor cell entrapment should be avoided by preventing major surgical procedures prior to the definitive treatment with CRS and HIPEC. 4) Mechanical removal of cancer cells and small nodules by mechanical irrigation prior to HIPEC is necessary. 5) A response must be generated using cancer chemotherapy to eradicate small volume residual disease that will remain even after a complete cytoreduction by visual inspection. 6) The benefits of multiple cycles of normothermic intraperitoneal and intravenous chemotherapy (NIPEC) used long-term to help preserve the surgical complete response needs to be integrated into the overall plan of management. Currently, with peritoneal metastases from high grade disease perioperative chemotherapy usually fails to maintain the surgical complete response. Major modifications of the perioperative chemotherapy using HIPEC, early postoperative intraperitoneal chemotherapy (EPIC) and NIPEC long-term will go far towards optimizing the treatment of peritoneal metastases no matter what the primary gastrointestinal or gynecologic malignancy is being treated.