Prevention and early treatment of peritoneal metastases from colorectal cancer: Second-look laparotomy or prophylactic HIPEC?

摘要

Peritoneal metastases (PM) represent the second most comriion site of disease progression for colorectal cancer (CRC), after liver metastases [1]. In two recent population-based studies, synchronous PM occurred in 4.3-7.1% of patients, and metachronous PM in 4.2-4.5% [1,2]. CRC-PM are associated with poor prognosis. Median survival was about 6 months in unselected case-series treated with supportive/palliative therapies or outdated 5-fluorouracil-based systemic chemotherapy (s-CT) [2,3]. More effective drugs, such as oxaliplatin, irinoteean, bevacizumab, and cetuximab in K-RAS wild-type tumors have greatly improved response rates and survival in patients with advanced CRC, but recent reports suggest less survival benefit in PM, as compared with non-PM metastatic CRC [1,3].Given the absence of symptoms and current limitations of imaging in detecting small-volume PM, early diagnosis, and treatment are difficult. Theoretically, there are two windows of opportunity to overcome these limitations. Some authors have advocated second-look laparotomy after a reasonable time interval from resection of primary tumor for asymptomatic patients at high risk of developing colorectal PM. Other authors have tested adjuvant (or "prophylactic") intraperitoneal chemotherapy (ip-CT) at the time of primary surgery. Nevertheless, both options cannot be proposed to all the patients systematically, and primary tumor-related features predicting metachronous PM are still poorly understood.