Clinical Value of Serum p53 Antibody in the Diagnosis and Prognosis of Esophageal Squamous Cell Carcinoma

Background/Aim: Identifying useful biomarkers is central to selecting optimal therapeutic strategies for esophageal squamous cell carcinoma (ESCC). Serum p53 antibody (S-p53Ab), squamous cell carcinoma antigen (SCC-Ag), and carcinoembryonic antigen (CEA) were investigated to evaluate the significance of single and combined tumor markers in determining the diagnosis and prognosis of ESCC. Materials and Methods: Serum samples were obtained preoperatively from 133 patients with histologically-confirmed ESCC, including 32 patients with stage I (24.1%). Levels of S-p53Ab were assessed by enzyme-linked immunosorbent assay, using a new version of a highly specific, quantitative kit. The cut-off value for S-p53Ab was 1.3 U/ml. Results: S-p53Ab was detected in 39.1% (52 out of 133) of patients with ESCC, including 40.0% (20 out of 50) of patients with early-stage ESCC. Positive rates for S-p53Ab, CEA, and SCC-Ag among patients with stage I ESCC (n=32) were 40.6%, 12.5%, and 31.3%, respectively. Positivity for S-p53Ab was not associated with positivity for CEA or SCCAg (p=0.249 and 0.747, respectively). The positive rate for diagnosis of ESCC increased from 39.1% to 65.4% when Sp53Ab was combined with SCC-Ag in this study. We found no significant correlation between the presence of S-p53Ab in ESCC and overall survival. Conversely, Cox regression analysis revealed that the International Union Against Cancer/TNM classification and systemic inflammation score were independent prognostic factors for ESCC in this series (hazard ratio(HR)=3.811, 95% confidence interval(CI)=1.548-9.378, p=0.004; and HR=2.218; 95% CI=1.087-4.523, p=0.029, respectively). Kaplan-Meier analysis revealed significant differences between patients with elevated S-p53Ab and SCC-Ag and patients with elevated levels of only one or neither of these factors (p=0.009). Conclusion: The diagnostic rate with S-p53Ab was better than that with SCC-Ag and CEA in patients with early-stage ESCC. Combined detection of S-p53Ab and SCC-Ag can markedly improve diagnostic sensitivity and may permit more accurate stratification of patients with ESCC.