Time course of serum C-reactive protein levels during induction chemoradiotherapy and its correlation with treatment response and survival in patients with advanced esophageal squamous cell carcinoma.

Preoperative serum C-reactive protein (CRP) levels have been shown to be of prognostic significance in patients with advanced esophageal carcinoma. However, the clinical significance of serum CRP levels in patients with unresectable or marginally resectable tumors in the absence of induction therapy has not been fully elucidated in relation to treatment response and prognosis. Thirty-four patients with clinical T3-T4 esophageal squamous cell carcinoma who underwent induction chemoradiotherapy (CRT) followed by esophagectomy were enrolled in this retrospective study. Serum CRP levels were measured during the course of CRT, i.e., prior to, during (1, 2, 3 and 4 weeks following initiation) and after CRT (prior to surgery). The association between CRP levels, CRT response and survival was analyzed. Elevated serum CRP levels exhibited a favorable decrease 2-3 weeks following CRT initiation in pathological responders and CRP ≤0.3 mg/dl at 2 and 3 weeks following CRT initiation, as well as prior to surgery, was significantly correlated with responders. In patients with pretreatment CRP >0.3 mg/dl (67.6% of patients in this study), CRP ≤0.3 mg/dl at 2 and 3 weeks following CRT initiation predicted responders with accuracies of 87.0 and 73.9%, respectively. In the univariate survival analysis, CRP levels 3 weeks following CRT initiation, as well as CRP levels prior to surgery and pathological stage, were significant prognostic factors, although CRP levels prior to surgery was the only independent prognostic factor in the multivariate analysis. Serum CRP levels during the course of CRT may be of prognostic and predictive significance for the CRT response in patients with unresectable or marginally resectable esophageal squamous cell carcinoma who undergo induction CRT.