Managing the peritoneal surface component of gastrointestinal cancer. Part 1. Patterns of dissemination and treatment options.

Until recently, peritoneal carcinomatosis was a universally fatal manifestation of gastrointestinal cancer. However, two innovations in treatment have improved outcome for these patients. The new surgical interventions are collectively referred to as peritonectomy procedures. During these procedures, all visible cancer is removed in an attempt to leave the patient with only microscopic residual disease. Perioperative intraperitoneal chemotherapy, the second innovation, is employed to eradicate small-volume residual disease. The intraperitoneal chemotherapy is administered in the operating room with moderate hyperthermia and is referred to as heated intraoperative intraperitoneal chemotherapy. If tolerated, additional intraperitoneal chemotherapy can be administered during the first 5 postoperative days. The use of these combined treatments, i.e., cytoreductive surgery and intraperitoneal chemotherapy, improves survival, optimizes quality of life, and maximally preserves function. Part 1 of this two-part article describes the natural history of gastrointestinal cancer with carcinomatosis, the patterns of dissemination within the peritoneal cavity, and the benefits and limitations of peritoneal chemotherapy. Peritonectomy procedures are also defined and described. Part 2, to be published next month in this journal, discusses the mechanics of delivering perioperative intraperitoneal chemotherapy and the clinical assessments used to select patients who will benefit from combined treatment. The results of combined treatment as they vary in mucinous and nonmucinous tumors are also discussed.