[Meta analysis of whether cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy can improve survival in patients with colorectal cancer peritoneal metastasis].

To explore whether the cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS+HIPEC) can improve the survival rate of colorectal cancer patients with peritoneal metastasis. The relevant studies were systematically retrieved from PubMed, Embase, Cochrane Library, CNKI, Wanfang, VIP database, and the study of French Elias' team on peritoneal metastasis was retrieved manually. Inclusion criteria: (1) The patients were colorectal cancer peritoneal metastasis. (2) There were CRS+HIPEC treatments (treatment group) and other treatments (control group). (3) Survival analysis data of treatment group and control group were available. (4) Types of studies were randomized controlled trials, cohort studies, or case-control studies. (5) The literature was in Chinese or English. Exclusion criteria: (1) studies without full-text; (2) studies without complete data. The literature screening and data extraction were carried out by two people independently, and the third person decided on the literature with differences. The extracted data included authors, year of publication, number of patients, time of enrollment, time of follow-up, studies design, treatment regimen, hazard ratio (HR) and 95% CI of treatment group and control groups. If the HR and 95% CI of the treatment group and control group were not provided in the literature, Engauge Digitizer 11.1 software was used to extract the time of follow-up and the survival rate at the corresponding time point from the survival curves of both groups, and the HR and 95% CI of both groups were calculated by combining the number of both groups. The quality of study was evaluated by Newcastle-Ottawa scale (NOS) or Cochrane collaboration's tool for assessing risk bias. STATA 15.1 software was used for statistical analysis. HR and 95% CI of both groups were pooled and analyzed. Inter-trial heterogeneity was assessed by test and I(2) statistics. When there was no significant heterogeneity ( test: ≥0.10), fixed-effect model was used for pooled analysis. When significant heterogeneity existed ( test: <0.10), random effect model was used for pooled analysis, and subgroup analysis was used to find out the source of heterogeneity. Sensitivity analysis was used to evaluate the stability of the pooled results. Publication bias was assessed by Egger's test and Begg's test (<0.05 indicated publication bias) and it is reflected by the visual symmetry of Begg's funnel plot on the natural logarithm of HR. A total of 10 studies were enrolled in the meta-analysis, including 1 randomized controlled trial and 9 cohort studies. The risk of bias in 1 randomized controlled trial was uncertain, and 9 cohort studies were all higher than 7 points, indicating high quality literatures. There were 781 patients in treatment group receiving CRS+HIPEC and 2452 patients in control group receiving other treatment, including tumor cytoreductive surgery (CRS), palliative chemotherapy (PC) and intraperitoneal chemotherapy (IPC). The results of pooled analysis by random effect model showed that the OS rate in treatment group was significantly higher than that in control group (HR=0.43, 95% CI: 0.34-0.54), but the heterogeneity of the study was high (=0.024, (2)=52.9%). The subgroup analysis of different control treatments showed that the OS rate in treatment group was significantly higher than that in CRS control group (HR=0.63, 95% CI: 0.44-0.90), in PC control group (HR=0.37, 95% CI: 0.32-0.43), in CRS+ IPC control group (HR=0.60, 95% CI: 0.37-0.96), and the heterogeneity of each subgroup was low (CRS control group: =0.255, (2)=22.9%; PC control group: =0.222, (2)=29.9%; CRS+IPC control group: =0.947, (2)=0). Due to the low heterogeneity of subgroups, fixed-effect models were used to pool and analysis. The results of sensitivity analysis revealed that there was little difference between the pooled analysis results after each study was deleted, suggesting that the pooled analysis results were more reliable. Publication bias detection of each study showed Begg's test (=0.088) >0.05 and Egger's test (=0.138)>0.05. According to the Begg's funnel plot, the scatter point distribution was basically symmetric, indicating that there was no publication bias in the included study. CRS+HIPEC can improve the OS of patients with colorectal cancer peritoneal metastasis.