Background Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are effective routine treatments for colorectal peritoneal metastases (PMs). However, the safety and efficacy of neoadjuvant chemotherapy (NAC) before CRS+HIPEC are poorly understood. Therefore, this study aimed to assess the perioperative safety and long-term efficacy for patients with synchronous colorectal PM who received NAC prior to CRS+HIPEC.Method Patients with synchronous colorectal PM who received NAC prior to CRS+HIPEC were systematically reviewed at the China National Cancer Center and Huanxing Cancer Hospital from June 2017 to June 2019. Clinicopathologic characteristics, perioperative parameters, and survival were compared between patients who underwent CRS+HIPEC with NAC (NAC group) and those who underwent CRS+HIPEC without NAC (non-NAC group).Results The study enrolled 52 patients, with 20 patients in the NAC group and 32 in the non-NAC group. In the NAC group, the proportion of patients with a peritoneal carcinomatosis index (PCI) score < 12 was significantly higher than that in the non-NAC group (80.0% vs 50.0%, P=0.031), and more patients received complete cyoreduction (80.0% vs 46.9%, P=0.018). The two groups had comparable grade III/IV complications and similar reoperation and mortality rates (P>0.05). However, patients who received NAC prior to CRS+HIPEC experienced lower platelet counts (151.9 vs 197.7 ×109/L, P=0.036) and neutrophil counts (4.7 vs 7.2×109/L, P=0.030) on postoperative day 1. Compared with the non-NAC group, more patients in the NAC group survived for two years (67.4% vs. 32.2%, respectively, P = 0.044). However, the CC score (HR, 2.99; 95% CI, 1.14-7.84; P=0.026), rather than NAC, was independently associated with OS in the multivariable analysis after controlling for confounding factors.Conclusion NAC administration before CRS+HIPEC can be regarded as a safe and feasible treatment for patients with colorectal PM with comparably low mortality and acceptable morbidity. Nevertheless, the administration of NAC before CRS+HIPEC conferred a greater survival benefit to patients, even though NAC was not identified as an independent factor for OS after controlling for confounding factors.

Background Currently, few studies have evaluated effectiveness of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in young patients with peritoneal metastasis (PM) of colorectal cancer (CRC) origin.Method Clinicopathological characteristics, perioperative data and survival outcomes in young patients, defined as being 50 years or less (n=23), performing CRS+HIPEC between June 2017 to June 2019 were reviewed and compared with older patients, defined as aged over 50 years (n=47).Results Compared with older patients, young patients were more likely to present with PM at the time of diagnosis (78.3% vs 51.1%, P=0.029) and exhibit a mucinous and signet-ring histology (60.9% vs 29.8%, P=0.013). The cancer-specific survival (CSS) after CRS+HIPEC in two groups are similar. On multivariate Cox regression, rectal origin (HR, 2.51, 95%CI, 1.11-5.67; P=0.027) and mucinous/signet adenocarcinoma (HR, 2.20, 95%CI, 1.02-4.74; P=0.044) were independent risk factors for poor CSS.Conclusion Younger patients (aged ≤50 years) with PM of CRC origin presented more often with synchronous PM than older patients. Although tend to exhibit a aggressive nature, they derive similar benefit from CRS+HIPEC as older patients.