Mini-array of multiple tumor-associated antigens (TAAs) in the immunodiagnosis of esophageal cancer

Sera of cancer patients may contain antibodies that react with a unique group of autologous cellular antigens called tumor-associated antigens (TAAs). The present study aimed to determine whether a mini-array of multiple TAAs would enhance antibody detection and be a useful approach in esophageal cancer detection and diagnosis. Our mini-array of multiple TAAs consisted of eleven antigens, p53, pl6, Impl, CyclinB1, C-myc, RalA, p62, Survivin, Koc, CyclinD1 and CyclinE full-length recombinant proteins. Enzyme-linked immunosorbent assays (ELISA) were used to detect autoantibodies against eleven selected TAAs in 174 sera from patients with esophageal cancer, as well as 242 sera from normal individuals. In addition, positive results of ELISA were confirmed by Western blotting. In a parallel screening trial, with the successive addition of antigen to a final total of eleven TAAs, there was a stepwise increase in positive antibody reactions. The eleven TAAs were the best parallel combination, and the sensitivity and specificity in diagnosing esophageal cancer was 75.3% and 81.0%, respectively. The positive and negative predictive values were 74.0% and 82.0%, respectively, indicating that the parallel assay of eleven TAAs raised the diagnostic precision significantly. In addition, the levels of antibodies to seven antigens, comprising p53, Impl, C-myc, RalA, p62, Survivin, and CyclinD1, were significantly different in various stages of esophageal cancer, which showed that autoantibodies may be involved in the pathogenesis and progression of esophageal cancer. All in all, this study further supports our previous hypothesis that a combination of antibodies might acquire higher sensitivity for the diagnosis of certain types of cancer. A customized mini-array of multiple carefully-selected TAAs is able to enhance autoantibody detection in the immunodiagnosis of esophageal cancer and autoantibodies to TAAs might be reference indicators of clinical stage.