Prognostic Value of C-Reactive Protein in Esophageal Cancer: a Meta-analysis

Background: The classical inflammatory biomarker, C-reactive protein (CRP), has been identified to be related to progression of esophageal cancer. Some research showed that elevated pretreatment serum CRP indicated a poor prognosis, but results have been inconsistent. Materials and Methods: We searched the Medline, Embase and the Cochrane Central Search Library for suitable studies and a meta-analysis of eleven (1,886 patients) was conducted to examine the relationship between elevated serum CRP level and overall survival (OS) in esophageal cancer cases. Moreover, correlation analyses were conducted to assess links between pretreatment serum CRP level and tumor node metastasis (TNM) stage as well as T, N, M grade, respectively. Results: The pooled analysis showed that elevated pretreatment serum CRP level was significantly associated with poorer overall survival (HR 2.09, 95%CI 1.52-2.87, p<0.01). Subgroup analyses were conducted by "country", "cut-off value", "treatment" and "number of patients", and no single factor could alter the result. Elevated pretreatment serum CRP was significantly correlated with more advanced TNM stage and T, N, M grade respectively. Conclusions: Elevated pretreatment serum CRP levels are associated with poorer prognosis in esophageal cancer patients, and could serve as a useful biomarker for outcome prediction.