Abstract:

Objective To investigate the expression of receptor tyrosine kinase⁃like orphan receptor 2 in the papillary thyroid carcinoma and its clinical significance. Methods The expression level of ROR2 protein in the PTC tissues and normal thyroid tissues was detected by immunohistochemistry and Western blot. The clinic pathologi⁃ cal characteristics of PTC patients with different expression levels were compared. The relationship between the level of ROR2 protein expression and postoperative recurrence of PTC patients was analyzed by Kaplan Meier method. The influencing factors of postoperative recurrence of PTC was analyzed with Cox proportional hazard regression. Results The positive expression rate of ROR2 protein in the PTC tissues was 74.46%，which was significantly higher than that in the normal thyroid tissues（13.75%）（χ2 = 83.419，P < 0.001），and the high expression rate of ROR2 protein in the PTC tissues was significantly higher than that in the normal thyroid tissue. High expression of ROR2 protein was positively correlated with multiple lesions，capsule invasion，lymph node metastasis，distant metastasis， and higher TNM stage in the PTC patients. The high expression of ROR2 protein was an independent risk factor of postoperative RFS（HR = 2.143，95%CI：1.119 ~ 4.597，P < 0.001）. The RFS rate of the patients with high expres⁃ sion of ROR2 protein was significantly lower than that of the patients with low expression（χ2 = 4.073，P = 0.044）. Conclusion The high expression rate of ROR2 protein in PTC tissues is significantly higher than that in normal thyroid tissues. The high expression of ROR2 protein is positively correlated to such adverse events in the disease progression as multiple lesions，capsule invasion，lymph node metastasis，distant metastasis，and higher TNM stage. High expression of ROR2 protein is an independent risk factor of postoperative recurrence of PTC，indicating that ROR2 protein can be potentially used as a biomarker for early diagnosis and prognosis evaluation of PTC.

Key words:

papillary thyroid carcinoma, ROR2, expression, clinic pathological characteristics, recurrence