Preoperative elevation of serum C‐reactive protein as an indicator of poor prognosis for early‐stage esophageal squamous cell carcinoma

Preoperative elevation of serum C‐reactive protein (CRP) is reportedly associated with poor prognosis in several types of cancer. This study investigated the role of serum CRP as a prognostic factor in early‐stage esophageal squamous cell carcinoma (ESCC). The preoperative serum CRP levels were measured in 156 newly diagnosed pT1–2N0M0 patients using an enzyme‐linked immunosorbent assay. Correlations between serum CRP levels and other clinical parameters were analyzed. Multivariate analyses were performed to find prognostic markers using Cox's proportional hazards model. CRP concentrations were within the normal range in 117 (75%) individuals, but were elevated in 39 (25%) patients. Serum CRP levels were significantly correlated with the tumor length (p= 0.032), depth (T classification, p= 0.0157), or histologic grade (p= 0.034). The overall 5‐year survival rates were 76.3% and 50.2% in the low‐ and high‐CRP groups, respectively (p= 0.005). By multivariate analyses, the elevated serum CRP level was found to be an independent prognostic factor for poor survival (hazard ratio = 2.131; p= 0.007), regardless of tumor classification or other prognostic factors. In conclusion, preoperative, high serum CRP is an independent determinant of poor prognosis in early‐stage ESCC.