Prognostic Significance of Serum Tumor Markers According to the Timing of Recurrence After Curative Esophagectomy for Esophageal Squamous Cell Carcinoma

BACKGROUND: Reliable biomarkers for predicting post-recurrence survival in esophageal squamous cell carcinoma (ESCC) remain limited. We evaluated the prognostic significance of three serum tumor markers routinely used in clinical practice (carcinoembryonic antigen [CEA], squamous cell carcinoma antigen [SCC], and serum p53 antibody [p53-Ab]) in patients with recurrent ESCC after curative esophagectomy. METHODS: Sixty patients who developed recurrence after curative resection for ESCC were retrospectively analyzed. Overall survival (OS) after recurrence was compared according to serum CEA, SCC, and p53-Ab levels measured at recurrence. Exploratory subgroup analyses were performed according to the timing of recurrence. RESULTS: Elevated SCC levels at recurrence were significantly associated with worse post-recurrence OS (p < 0.01), whereas CEA and p53-Ab levels were not. Multivariable analysis identified elevated SCC as an independent predictor of poor post-recurrence survival (hazard ratio, 2.50; 95% confidence interval, 1.18-5.33; p = 0.02). In the exploratory analysis according to recurrence timing, elevated SCC levels were associated with worse survival among patients with standard recurrence (p < 0.01), whereas no significant associations were observed for CEA or p53-Ab. Among patients with late recurrence, elevated p53-Ab levels showed a possible association with poorer survival (p = 0.05). CONCLUSIONS: Serum SCC measured at recurrence may serve as a prognostic biomarker for post-recurrence survival in patients with ESCC after curative esophagectomy. Exploratory analyses according to recurrence timing suggested that SCC may be particularly relevant in standard recurrence, whereas p53-Ab showed a possible prognostic association in late recurrence.