Combined detection of serum Dickkopf‐1 and its autoantibodies to diagnose esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma ( ESCC ) can be treated effectively if diagnosed at an early stage. We evaluated whether measurement of Dickkopf‐1 ( DKK ‐1) in combination of DKK ‐1 autoantibodies in serum may benefit early diagnosis of ESCC . Serum DKK ‐1 and DKK ‐1 autoantibodies were measured by enzyme‐linked immunosorbent assay in a training cohort (185 ESCC samples vs. 97 normal controls) and validated in a validation cohort (104 ESCC samples vs. 53 normal controls). Receiver operating characteristic ( ROC ) was applied to calculate diagnostic accuracy. Testing of DKK ‐1 and DKK ‐1 autoantibodies together could differentiate ESCC from normal controls (area under the ROC curve [ AUC ] 0.769, 95% confidence interval ( CI ), 0.715–0.823, 50.3% sensitivity, and 90.7% specificity in the training cohort; AUC 0.752, 95% CI , 0.675–0.829, 50.0% sensitivity, and 84.9% specificity in the validation cohort). Importantly, the diagnostic performance of the combination of DKK ‐1 and DKK ‐1 autoantibodies persisted in early ESCC patients ( AUC 0.780, 95% CI , 0.699–0.862, 50.0% sensitivity, and 90.7% specificity in the training cohort; AUC 0.745, 95% CI , 0.626–0.865, 53.8% sensitivity, and 84.9% specificity in the validation cohort). Furthermore, the levels of serum DKK ‐1 or DKK ‐1 autoantibody after surgical resection were lower, respectively, compared with the corresponding preoperative samples ( P  < 0.05). Our results suggest that measurement of DKK ‐1 combined with DKK ‐1 autoantibodies is a potentially valuable tool for the early detection of ESCC .