Prospective Clinical Application of Thioredoxin Reductase as a Novel Diagnostic Tumor Marker

Background: Developing a novel, efficient biomarker for detecting malignant tumors is essential for the early diagnosis of cancers. Our aim was to assess the diagnostic value of a potential plasma tumor marker, thioredoxin reductase (TR), which is expressed in many types of malignant tumor, for the non-invasive detection of cancers. Methods: The plasma activities of TR were measured in 1513 patients with common clinical diseases, 59 patients with benign tumors, and 154 patients with cancers and 586 healthy controls. The area under the ROC curve (AUC) of TR and logistic re-gression results of different groups were compared by sensitivity, specificity and Youden’s index. Diagnostic cut-offs and clinical reference intervals were established via ROC curve analysis. Re-sults: The logistic regression indicated that TR activity can discriminate between cancers and be-nign tumors or other common diseases very well (p < 0.0001), with an area under the curve from the receiver-operator characteristics between 0.91 and 0.96. The positive critical value was 2.51 and the cancer critical value was 9.90. The diagnostic gray zone (2.51- 9.90) may be associate