Colorectal cancer at high risk of peritoneal metastases: long term outcomes of a pilot study on adjuvant laparoscopic HIPEC and future perspectives

// Charlotte E.L. Klaver 1 , Roos Stam 1 , Didi A.M. Sloothaak 1 , Johannes Crezee 2 , Willem A. Bemelman 1 , Cornelis J.A. Punt 3 and Pieter J. Tanis 1 1 Department of Surgery, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands 2 Department of Radiation Oncology, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands 3 Department of Medical Oncology, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands Correspondence to: Pieter J. Tanis, email: p.j.tanis@amc.uva.nl Keywords: colorectal cancer, peritoneal metastases, adjuvant HIPEC Received: September 26, 2016 Accepted: March 10, 2017 Published: April 17, 2017 ABSTRACT Objective: Early detection of peritoneal metastases (PM) of colorectal cancer (CRC) is difficult and treatment options at a clinically overt stage are limited. Potentially, adjuvant laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) is of value. The aim of this study was to present long term oncological outcomes of a pilot study on adjuvant HIPEC to reduce development of PMCRC, with systematic review of literature. Methods: Long term oncological outcomes of ten patients who underwent laparoscopic HIPEC within eight weeks after resection of primary CRC in the pilot study were retrospectively collected. A systematic search of literature was performed on studies describing the use of HIPEC in patients with CRC at high risk of developing PM. Results: The median follow-up was 54 months (range 49-63). All patients were alive at the last follow-up moment and none of them had developed PM. Two patients had developed pulmonary metastases. Systematic review revealed five small cohort studies, including two matched comparisons. Peritoneal recurrences were found in 0% to 9% after adjuvant HIPEC, which was 28% and 43% in the two control groups, respectively. Disease free and overall survival were significantly higher in favour of HIPEC. Conclusion: Long term follow-up of ten patients included in a pilot study on adjuvant HIPEC revealed no peritoneal recurrences. This result is in line with other published pilot studies, a promising observation. However, the outcomes of the Dutch randomized COLOPEC trial and similar trials worldwide should be awaited for definitive conclusions on the effectiveness of adjuvant HIPEC.