CXC motif ligand 12 as a novel diagnostic marker for papillary thyroid carcinoma.

BACKGROUND We subjected chemokine (C-X-C motif) ligand 12 (CXCL12) to immunohistochemistry to determine its utility as a novel diagnostic marker for papillary thyroid carcinoma (PTC) in comparison to cytokeratin 19 (CK19), Hector Battifora mesothelial epitope-1 (HBME-1), and galectin-3. METHODS We analyzed the expressions of CXCL12, CK19, HBME-1, and galectin-3 using immunohistochemical staining in 258 cases of thyroid lesions (196 PTCs and 62 thyroid lesions excluding PTC). RESULTS Remarkably, CXCL12 expression was exclusively found in PTC compared to other thyroid lesions (90.8% vs 3.2%; p < .001). In total, 91.1% (62 of 68) of the variant PTCs and 90.6% of conventional type (116 of 128) were associated with CXCL12 immunohistochemical expression, irrespective of the histological subtype. In contrast, very few of the thyroid lesions, excluding PTC, were positive for CXCL12 (2 of 62; 3.2%). Diagnostic performances for PTCs were as follows: sensitivity, 90.8%; specificity, 96.8%; positive predictive value, 98.9%; negative predictive value, 76.9%; and diagnostic accuracy, 92.2%. CONCLUSION Our findings indicate that CXCL12 might serve as an effective novel supplementary diagnostic marker for PTC.