Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the management of gastrointestinal cancers with peritoneal metastases: Progress toward a new standard of care

• The incidence of peritoneal metastases with primary gastrointestinal cancer is less common with recurrence.
• Peritoneal dissemination can be prevented by meticulous surgical technique, sometimes HIPEC is necessary.
• Complete cytoreduction can reduce the volume of disease so that HIPEC results in good outcomes.
• The management of peritoneal metastases includes prevention, synchronous and metachronous treatment protocols.
• The availability of HIPEC may determine if prevention protocols can be applied.

Peritoneal metastases from gastrointestinal cancer was, in the past, accepted as an inevitable component of the natural history of these diseases. It is a major cause of intestinal obstruction, fistula formation, and bowel perforation as the recurrent malignancy progresses to a terminal condition. Peritoneal metastases may be caused by full thickness penetration of the bowel wall by the primary cancer or by spilled cancer cells released into the peritoneal space by surgical trauma. Two new surgical technologies that have evolved to manage peritoneal metastases are cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). This combined treatment strategy uses peritonectomy procedures and visceral resections to reduce the disease in the abdomen and pelvis to a macroscopic volume. Then, HIPEC is used to preserve the complete cytoreduction by controlling the minimal residual disease. Since the extent of peritoneal metastases, as measured by the peritoneal cancer index (PCI), is crucial to a favorable outcome, prognostic indicators are used to select patients for treatment. The combined treatment may be used to prevent peritoneal metastases in gastrointestinal cancer patients having a resection of the primary malignancy. This is especially important in gastric cancer patients with serosal invasion. The combined treatment may be used synchronously with the primary cancer resection if peritoneal metastases are already apparent. The treatment is most frequently used with metachronous peritoneal metastases diagnosed in follow-up. Cure of peritoneal metastases is an option in selected patients and its knowledgeable use is progressing towards a new standard of care.