PurposeThe prognosis of esophageal cancer is dismal, and the 3-year overall survival of cStage III does not reach 50.0%. C-reactive protein (CRP) is a well-known protein that reflects the short- and long-term operative outcomes of esophageal cancer. However, since elevated CRP levels are often observed in cStage III esophageal cancer, whether or not CRP still reflects the prognosis is unclear.MethodsEighty-four patients who were diagnosed with cStage III esophageal cancer and underwent R0/1 operation from January 2007 to December 2014 were retrospectively evaluated.ResultsThe mean age was 66.8 years, and the majority of patients were male. The median preoperative and postoperative CRP levels were 0.15 and 1.47 mg/dl, respectively. A majority of the patients underwent thoracoscopic surgery, and the median blood loss and operation duration were 456 ml and 11.6 h, respectively. Forty-six patients (54.8%) died during the observation period, and the 3-year overall survival was 52.4%. A multivariate analysis showed that the preoperative CRP level, postoperative albumin level, blood loss, and complications were independent prognostic factors. A multiple linear regression analysis showed that an elevated postoperative CRP level was affected by the operation duration and preoperative CRP levels.ConclusionsThese findings suggest that the preoperative CRP level is a prognostic factor for cStage III esophageal cancer and that postoperative elevation in the CRP level is affected by the operation duration.