Peritoneal and Serum or Plasma Interleukin-6 as Early Biomarkers for Colorectal Anastomotic Leakage after Colorectal Surgery in Patients with Colorectal Cancer: A Systematic Review and Meta-Analysis

Background: The early detection of colorectal anastomotic leakage (CAL) remains challenging despite advancements in diagnostic methods.Reliable markers are needed to reduce patient morbidity and mortality.Cytokines in drain fluid and systemic cytokine levels have shown potential as predictive markers for CAL, but more robust evidence is required.This systematic review and meta-analysis aimed to evaluate the importance of peritoneal and serum or plasma interleukin-6 (IL-6) levels in the early detection of CAL after colorectal surgery in colorectal cancer patients.Methods: We conducted a comprehensive search in PubMed, Scopus, and Web of Science for relevant studies published before May 2023.Studies investigating plasma/serum, peritoneal IL-6 levels (or both) in CAL following colorectal surgery in colorectal cancer patients were included.Data on the mean and standard deviation of circulating and peritoneal IL-6 levels were extracted for CAL and non-CAL patients.Mean differences were analyzed for each postoperative day (POD) using OpenMeta [analyst].Results: Sixteen articles were included in this meta-analysis, with 13 measuring peritoneal IL-6 levels and six measuring of circulating IL-6 levels.The systematic review included seven articles evaluating peritoneal IL-6 levels, revealing no significant elevation in CAL patients compared to non-CAL patients at any POD.Meta-analysis for circulating IL-6 levels was not feasible.Conclusions: Based on the available evidence, peritoneal and serum or plasma IL-6 levels cannot be considered early markers for CAL following colorectal surgery in colorectal cancer patients.Further high-quality studies are necessary to determine whether IL-6 could be a reliable marker for anastomotic leakage after colorectal surgery.