The impact of surgical staging in patients with colorectal peritoneal metastases scheduled for CRS-HIPEC.

Objectives: Surgical staging procedures are used to select patients with peritoneal metastases for surgery. We aimed to evaluate the impact of surgical staging procedures and the risk of abdominal wall recurrences in patients with peritoneal metastases scheduled for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Methods: Data were collected from a prospective maintained HIPEC register January 2012-December 2019. Patients with colorectal peritoneal metastases were included. Information about surgical staging procedures was registered. Results were then compared with those registered at definite CRS-HIPEC surgery and survival was analysed in relation to surgical staging procedures. Results: In total, 138 patients were included, of whom 32 had undergone a surgical staging procedure before CRS-HIPEC. Median overall survival in the surgical staging group was 1.89 years and in the non-staging group 3.07 years (p=0.060). In the surgical staging group, eight patients developed abdominal wall recurrences (25 %) compared with three (3 %) in the non-staged group. Eight staged patients (25 %) were considered inoperable at definite surgery (open-close). PCI score (p<0.001) was higher at definite surgery in patients who had undergone a staging laparoscopy. Factors associated with shorter overall survival in multivariate analysis were: open and close, PCI ≥21 and presence of signet ring cells. However, a staging procedure was not associated with a shorter overall survival. Conclusions: Surgical staging procedures is a valuable assessment of inoperability, though at the expense of more frequent abdominal wall recurrences. Imaging-based strategies may provide useful insights into whether surgical staging is the most effective approach for patient selection.