C-Reactive Protein and C-Reactive Protein-Based Scores to Predict Survival in Esophageal and Junctional Adenocarcinoma: Systematic Review and Meta-Analysis

Background Esophageal adenocarcinoma (EAC) has a poor prognosis; predictive markers of prognosis would facilitate advances in personalized therapy. C-reactive protein (CRP) and CRP-based scores are increasingly recommended across oncology; however, their role and value in EAC is unclear. This systematic review and meta-analysis examined CRP cut-point and scores and how they may best be applied in predicting survival in EAC. Methods A systematic literature search was conducted in EMBASE, Medline, Web of Science, Cochrane, Scopus and CINAHL databases, from inception to 1st October 2020. Studies reporting data from adults with EAC including adenocarcinoma of the gastro-esophageal junction (AEG), pre-treatment CRP or CRP-based score and Hazard Ratio (HR) for survival were included. QUIPS tool assessed risk of bias. Meta-analysis was undertaken. Results A total of 819 records were screened. Eight papers were included, with data for 1475 people. CRP cut-points ranged from 2.8 to 10 mg/L. The Glasgow Prognostic Score (GPS) and modified GPS were the most commonly reported scores. On meta-analysis, elevated preoperative GPS/mGPS was significantly associated with worse overall survival (hazards ratio [HR] 1.81, 95% confidence interval [CI] 1.25-2.62, p = 0.002); results were similar in subgroup analyses of multimodal treatment, M0 disease, and R0 resection. Conclusions This is the first review to evaluate comprehensively the evidence for CRP and CRP-based scores in EAC. Meta-analysis demonstrated that elevated preoperative GPS or mGPS was significantly associated with reduced overall survival in EAC, including AEG. There is insufficient evidence to support use of CRP alone. Future studies should examine GPS/mGPS in EAC prospectively, alone and combined with other prognostic markers.