Predictive significance of serum dipeptidyl peptidase-IV in papillary thyroid carcinoma

BACKGROUND: The significance of serum dipeptidyl peptidase-IV (DPP-IV) in papillary thyroid carcinoma (PTC) has not been elucidated. OBJECTIVE: This study aimed to assess the role of serum DPP-IV in the carcinogenesis and prognosis of PTC. METHODS: The serum DPP-IV concentration was measured in 171 male patients with PTC, 81 male patients with a benign thyroid nodule (BTN), and 52 male healthy controls (HCs). Multivariate logistic regression and Cox regression analyses were performed to evaluate the correlations between variables. Receiver operating characteristic (ROC) curves were used to calculate the diagnosis accuracy. RESULTS: The ROC curve indicated a good performance of DPP-IV for discriminating PTC from BTN, with an area under the curve (AUC) of 0.881 (95% CI, 0.840-0.922). Serum DPP-IV demonstrated a modest performance in predicting nonstructurally persistent disease/recurrent disease (NSPRD) survival, with an AUC of 0.778 (95% CI, 0.635-0.922). A serum DPP-IV level ⩾ 250 nkat/L (HR, 6.529; 95% CI, 2.090-20.398; P= 0.001) and an advanced tumor, lymph node, metastasis (TNM) stage (HR, 4.677; 95% CI, 1.498-14.605; P= 0.008) were found to be independent factors for predicting SPRD. PTC patients with a DPP-IV level ⩾ 250 nkat/L had a worse outcome than those with a DPP-IV level < 250 nkat/L (P< 0.001). CONCLUSIONS: Serum DPP-IV may be a predictive biomarker for PTC diagnosis and prognosis in Chinese male patients.