Optimized Cutoff Value of Serum Squamous Cell Carcinoma Antigen Concentration Accurately Predicts Recurrence After Curative Resection of Squamous Cell Carcinoma of the Esophagus.

BACKGROUND: Squamous cell carcinoma antigen (SCC-Ag) and carcinoembryonic antigen (CEA) are widely used in clinical practice to predict the prognosis of patients with esophageal squamous cell carcinoma (ESCC). However, their predictive values for prognosis are controversial. This study determined optimal cutoff values of serum SCC-Ag and CEA concentrations for predicting postoperative recurrence of ESCC, which enabled selection of high-risk patients. METHODS: The study retrospectively analyzed 427 patients who underwent curative resection for ESCC. The optimal cutoff values of preoperative SCC-Ag and CEA concentrations for predicting postoperative recurrence were determined using combined analysis of hazard ratios and sensitivities for recurrence. Using the optimal cutoff value, the study evaluated survival, recurrence patterns, and temporal changes in marker concentrations. RESULTS: The preoperative SCC-Ag concentration of 1.1 ng/ml was the optimal cutoff value for predicting postoperative recurrence, whereas precise cutoff values could not be determined for preoperative CEA concentrations. High preoperative SCC-Ag concentrations (> 1.1 ng/ml), which were significantly associated with more aggressive tumor phenotypes and shorter disease-free survival, were identified as an independent prognostic factor in the multivariable analysis. High preoperative SCC-Ag concentrations were significantly associated with greater prevalence of lung/pleura and local recurrences. Normalization of serum SCC-Ag concentrations after neoadjuvant treatment or esophagectomy was not associated with a decreased risk of postoperative recurrence. CONCLUSIONS: The optimal cutoff value of preoperative SCC-Ag concentrations that predicted recurrence of ESCC was 1.1 ng/ml, illuminating the utility of serum SCC-Ag concentrations as an easily measurable tool for selecting a perioperative management strategy.