C-Reactive Protein in Peritoneal Fluid for Predicting Anastomotic Leakage After Colorectal Cancer Surgery: A Systematic Review and Meta-Analysis.

Background: Anastomotic leakage (AL) is a serious and potentially fatal complication that can occur after colorectal cancer (CRC) surgery, and it significantly affects patient recovery and increases morbidity. While serum C-reactive protein (CRP) is a recognized systemic inflammatory marker, the level of CRP in peritoneal fluid may serve as a more specific and localized biomarker for early AL detection. This meta-analysis explores the diagnostic potential of peritoneal fluid CRP, aiming to enhance postoperative care for CRC patients. Methods: A comprehensive literature search was conducted following the PRISMA guidelines. Eligible studies were included based on strict inclusion and exclusion criteria. Diagnostic accuracy was pooled using a random-effects model. The risk of bias was assessed using the QUADAS-2 tool. Results: The pooled sensitivity and specificity were 0.74 and 0.83, respectively, with an area under the curve (AUC) of 0.84, indicating good diagnostic accuracy. The overall diagnostic performance was consistent for sensitivity with no significant heterogeneity, but high heterogeneity was observed for specificity, suggesting variability between studies. Subgroup analysis revealed improved diagnostic performance between postoperative days 5-7 and higher CRP cut-off values (70-150 mg/L). The analysis confirmed the stability of the results through a sensitivity analysis and found no significant publication bias. Conclusions: Peritoneal fluid CRP is a reliable biomarker for detecting AL after CRC surgery, especially in the later postoperative period. However, heterogeneity in study methodologies and patient populations limits the generalizability of the findings. Future research should focus on standardizing protocols and exploring additional biomarkers to improve diagnostic accuracy.