Nasopharyngeal carcinoma (NPC) is prevalent in Southern China and Southeast Asia, and autoantibody signatures may improve early detection of NPC. In this study, serum levels of autoantibodies against a panel of six tumor-associated antigens (p53, NY-ESO-1, MMP-7, Hsp70, Prx VI, and Bmi-1) and Epstein-Barr virus capsid antigen-IgA (VCA-IgA) were tested by enzyme-linked immunosorbent assay in a training set (220 NPC patients and 150 controls) and validated in a validation set (90 NPC patients and 68 controls). We used receiver-operating characteristics (ROC) to calculate diagnostic accuracy. ROC curves showed that use of these 6 autoantibody assays provided an area under curve (AUC) of 0.855 [95% confidence interval (CI), 0.818-0.892], 68.2% sensitivity, and 90.0% specificity in the training set and an AUC of 0.873 (95% CI, 0.821-0.925), 62.2% sensitivity, and 91.2% specificity in the validation set. Moreover, the autoantibody panel maintained diagnostic accuracy for VCA-IgA-negative NPC patients [0.854 (0.809-0.899), 67.8%, and 90.0% in the training set; 0.879 (0.815-0.942), 67.4%, and 91.2% in the validation set]. Importantly, combination of the autoantibody panel and VCA-IgA improved diagnostic accuracy for NPC versus controls compared with the autoantibody panel alone [0.911 (0.881-0.940), 81.4%, and 90.0% in the training set; 0.919 (0.878-0.959), 78.9%, and 91.2% in the validation set), as well as for early-stage NPC (0.944 (0.894-0.994), 87.9%, and 94.0% in the training set; 0.922 (0.808-1.000), 80.0%, and 92.6% in the validation set]. These results reveal autoantibody signatures in an optimized panel that could improve the identification of VCA-IgA-negative NPC patients, may aid screening and diagnosis of NPC, especially when combined with VCA-IgA.
©2015 American Association for Cancer Research.