Zhou-Ci Zheng, Qing-Xuan Wang, Wei Zhang, Xiao-Hua Zhang, Du-Ping Huang

In contrast to the excellent prognosis for papillary thyroid carcinoma (PTC), the high incidence of lymph node metastasis (LNM) markedly increases the risk of recurrence and secondary surgery. Thus, novel biomarkers must be urgently identified to assess LNM for patients with PTC. NCOA5 is deeply involved in the progression of human cancer; however, its role in thyroid cancer remains unknown. Quantitative real-time polymerase chain reaction was conducted to investigate the expression of NCOA5 in PTC. RNA-seq data from The Cancer Genome Atlas (TCGA) database were downloaded to further understand the role of NCOA5 in PTC and its relationship with LNM. NCOA5 was significantly downregulated in PTC tissues when compared with that in adjacent noncancerous thyroid tissues both in our local cohort and TCGA database. Reduced expression of NCOA5 was significantly associated with aggressive clinicopathological features, including histological type, tumor stage, BRAF-V600E mutation, LNM, extrathyroid extension, and clinical stage. Moreover, logistic analysis indicated that reduced expression of NCOA5, age, histological type, and clinical stage are independent high-risk factors for LNM in PTC. Our study provides new insights and evidence that NOCA5 was significantly correlated with the progression of PTC and was particularly involved in LNM.