Multimodal treatment approaches for peritoneal carcinosis in colorectal cancer

15% to 20% of patients with metastatic colorectal cancer show isolated peritoneal carcinomatosis with significat clinical relevance. Their prognosis is poor, with a reported mean survival of less than one year. Moreover, there is a lack of knowledge regarding treatment optimally tailored to individual patients.

To identify and characterize the current treatment options for this condition, we reviewed pertinent literature retrieved by a PubMed search on the terms "peritoneal carcinomatosis," "colorectal cancer," "treatment," "hyperthermic intraperitoneal chemotherapy," "cytoreductive surgery," and "humans."

Most patients with peritoneal carcinomatosis are treated with systemic chemotherapy in addition to best supportive care. Some undergo surgical or interventional treatment, such as ostomy or stent placement for intestinal obstruction. About one-third are candidates for multimodal treatment, consisting of surgical cytoreduction with intraoperative hyperthermic intraperitoneal chemotherapy. The main selection criteria are limited tumor mass (peritoneal cancer index <20), absence of organ metastases, feasibility of complete macroscopic cytoreduction (absence of disseminated small bowel disease), and approval of the interdisciplinary tumor board. Patients selected in this way have a 5-year survival rate of 30% to 50% after multimodal treatment.

The treatment of peritoneal carcinomatosis is usually considered to be purely palliative, in view of the extensive spread of the disease. However, for a subgroup of patients multimodal treatment can be provided with curative intent. The available survival data support the provision of multimodal strategies, including cytoprotective surgery, intraoperative intraperitoneal and systemic chemotherapy, for patients with peritoneal carcinomatosis in specialized centers. This type of treatment should be incorporated into treatment algorithms and guidelines.