REGγ Is Associated with Lymph Node Metastasis and T-Stage in Papillary Thyroid Carcinoma

BACKGROUND This paper aimed to evaluate the expression of REGg and characterize its clinical significance in papillary thyroid carcinoma (PTC). MATERIAL AND METHODS In total, 54 patients with PTC who underwent partial or total thyroidectomy and cervical node dissection for PTC from February 2009 to September 2011 were retrospectively reviewed. Thyroid specimens and metastatic lymph nodes from 54 patients and normal thyroid tissues obtained from 13 volunteers were collected and analyzed. Tumor size, T-stage, and lymph nodes metastasis were recorded based on surgical pathology. Immunohistochemical (IHC) technology was performed to analyze REGg protein expression level. Corrections between the expression of REGγ and the clinicopathological factors were analyzed. RESULTS All the normal thyroid tissues were REGg-negative. REGγ was positive in 75.9% (41/54) of PTC tissues, of which 29 cases (29/42, 69.0%) were in T1-T2 stage and 12 cases (12/12,100%) were in T3-T4 stage. Positive REGγ was found in 21 cases (21/24, 87.5%) in T1-T2 stage with lymph nodes metastasis, while 11 cases were in T3-T4 stage with metastases to lymph nodes (11/11, 100%). High level of REGγ expression was significantly correlated with T-stage (P<0.05) and lymph node metastases (P<0.05). In addition, there was no statistically significant difference between the expression of REGγ and age, sex, tumor size, or tumor multiplicity (P>0.05). Using binary logistic regression model, positive REGγ was identified as a significant independent predictor factor of lymph node metastasis in PTC. CONCLUSIONS High expression of REGg seemed positively correlated with T-stage and lymph node metastasis in PTC tissues.