Abstract: [Abstract] Objective To evaluate the perioperative safety and long-term efficacy of preoperative in patients with simultaneous colorectal peritoneal metastasis before CRS+HIPEC.Methods This study retrospectively analyzed patients who received preoperative chemotherapy combined with CRS+HIPEC for simultaneous colorectal peritoneal metastasis in National Cancer Center and Huanxing Cancer Hospital from June 2017 to June 2019.A total of 52 patients were included in this study,and they were divided into preoperative chemotherapy group(n=20) and non-preoperative chemotherapy group(n=32) according to whether or not they had received preoperative chemotherapy.Results In the preoperative chemotherapy group,the proportion of patients with a peritoneal carcinomatosis index(PCI) >12 was significantly higher than in the non-preoperative chemotherapy group(80.0% vs.50.0%,P=0.031),while more patients achieved complete cytoreductives(80.0% vs 46.9%,P=0.018).There were no significant differences in the incidence of grade Ⅲ/Ⅳ complications,reoperation rates and mortality rates between the two groups(P>0.05).Platelet counts(151.9 ×10⁹/L和197.7×10⁹/L,P=0.036) and white blood cell count(4.7 ×10⁹/L和7.2×10⁹/L,P=0.030) were significantly lower on the first day after surgery in patients receiving preoperative chemotherapy.Patients in the preoperative group survived more than 2 years significantly more than those in the nonpreoperative group(67.4% vs 32.2%,P=0.044).Multivariate analysis showed that completeness of the cytoreduction score(HR,2.99;95% CI,1.14~7.84;P=0.026) was an independent risk factor for overall survival,but not preoperative chemotherapy.Conclusion For patients with peritoneal metastasis of colorectal cancer,preoperative chemotherapy before CRS+HIPEC is safe and feasible,with a relatively low incidence of complications and mortality.

Key words: cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, colorectal cancer, peritoneal metastasis, preoperative chemotherapy