Management of Unexpected Peritoneal Metastases with Primary Colorectal Cancer Using Second-Look Surgery with HIPEC

Background: Peritoneal metastases (PM) will be unexpectedly present in approximately 10% of colorectal cancer patients having primary cancer resection. In the past this was considered to be an incurable condition with a terminal outcome. In patients determined to have peritoneal dissemination at the time of resection, the intervention was considered palliative. Recently, long term benefit from definitive treatment of PM with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has become a reality. These treatments are now appropriate for primary appendiceal and colorectal cancer determined to have PM at the time of resection. Methods: Modifications of the initial management of colorectal cancer patients found upon exploration to have PM are explored in this manuscript. In these patients, not only the primary cancer but also the PM must be optimally treated. Results: The presentation of the primary colon or rectal cancer as asymptomatic, bleeding, obstructed or perforated is important in treatment planning. The surgical approach must facilitate subsequent interventions to definitely treat PM. Procedures performed on the primary cancer are designed to minimize tumor cell entrapment. These patients usually have short course of systemic chemotherapy prior to repeat intervention with HIPEC. Conclusion: CRS and HIPEC must be integrated into the management of colorectal cancer patients who have PM identified unexpectedly at the time of primary cancer resection. Major resections in the absence of HIPEC should not occur in these patients in order to preserve an intact peritoneum as the first line of defense against PM and avoid tumor cell entrapment in subsequent CRS and HIPEC procedures.