Patient selection in those undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases - systematic review and meta-analysis of prognostic factors in large cohorts.

INTRODUCTION

Cytoreductive surgery (CRS) with concurrent hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment for colorectal peritoneal metastases (CPM) which can offer a median overall survival of 41 months and improve quality of life. Judicious patient selection is critical for deriving the greatest benefit and avoiding overtreatment. This meta-analysis identifies prognostic factors associated with survival in large cohorts derived from prospectively maintained databases of CRS-HIPEC patient cohorts.

MATERIALS/

METHODS

A systematic review and meta-analysis was conducted to evaluate prognostic variables influencing overall survival (OS) and disease-free survival (DFS) in patients with CPM who underwent CRS-HIPEC.

RESULTS

Forty-five studies satisfied inclusion criteria for systematic review, with thirty-three studies included for qualitative synthesis. Incomplete cytoreduction, PCI, and grade III-IV complications were the strongest predictors of both OS and DFS. Tumour-specific factors associated with worse OS on pooled analysis included: poor differentiation, signet-ring cell pathology, nodal involvement, T4 stage, and rectal primary. Adjuvant/neoadjuvant systemic treatments had no significant impact on survival in this analysis. RAS mutations may be associated with poorer survival on exploratory analysis.

CONCLUSION

Survival after CRS-HIPEC was best determined by quantity of peritoneal disease (PCI) and the ability to achieve complete cytoreduction (CC-0). Major post-operative complications impact survival beyond short term morbidity. Baseline primary tumour-specific features also impacted survival.