Background and aim: We previously reported a novel tumor associated antigen (TTA) with molecular weight around 48 kDa that is a fragment derived from human DNA-topoiomerase I (TOP1). We termed the novel TM as TOPO48 and termed autoantibody against the TAA as anti-TOPO48 autoantibody. The aim of this study is to further investigate the clinical applications of the autoantibody in patients with esophageal squamous cell carcinomas (ESCC). Methods: Serum levels of the anti-TOPO48 autoantibody in 112 ESCC patients, 112 age- and gender-matched healthy controls and 75 patients with esophageal benign tumors were determined by using a specific anti-TOPO48 autoantibody ELISA. Then, we statistically evaluated its clinical significance. Results: We found that serum anti-TOPO48 autoantibody levels in ESCC patients were significantly higher than that in healthy controls and benign tumor patients (P = 0.001). The percentage of sera with a positive level of anti-TOPO48 autoantibody in early stages was significantly higher than that in advanced stages of the cancer patients when the maximum level of healthy control sera was taken as a cut-off value (P = 0.001). The area under ROC curve was 0.863 (95% CI =0.797-0.928) for healthy controls vs. early stage ESCC. In addition, patients with positive anti-TOPO48 autoantibody had significantly higher survival rate and longer survival time than that with negative anti-TOPO48 autoantibody in cancer patients (P = 0.038, 0.025 and 0.047 for all stages, early stage and advanced stage, respectively). Conclusions: Our results suggest that anti-TOPO48 autoantibody may be a potentially useful biomarker for early diagnosis and prognosis of ESCC. (C) 2017 Elsev-er Masson SAS. All rights reserved.