Analysis of CTn and PTHR1 expression and RET mutation in sporadic medullary thyroid carcinoma

WANG Hui; LIU Qinjiang; LI Xiaoqin

doi:10.3969/j.issn.1009-0460.2019.11.017

Abstract：Objective To investigate the expression of calcitonin ( CTn) and parathyroid hormone receptor 1 ( PTHR1) in sporadic medullary thyroid carcinoma (SMTC) and their relationships with RET mutation. Methods Immunohistochemical SP method was used to detect the expressions of CTn and PTHR1 in SMTC (64 cases), nodular goiter (55 cases) and normal thyroid (35 cases). RET mutation was detected by PCR direct sequencing. The relationships of expressions of CTn and PTHR1 with clinicopathological fea-tures in patients with SMTC and RET mutation were analyzed. Results The positive rate of CTn in SMTC was 90. 6%(58／64), high-er than 78. 2%(43／55) of nodular goiter and 68. 6%(24／35) of normal thyroid tissue. CTn expression was associated with tumor size and lymph node metastasis (P＜0. 05). The positive rates of PTHR1 in SMTC, nodular goiter and normal thyroid tissue were 81. 3%(52／64), 69. 1%(38／55) and 60. 0%(21／35), and the difference was not statistically significant (P＞0. 05). PTHR1 expression was not associated with gender, age, lymph node metastasis or capsule invasion, but only with tumor size (P＜0. 05). The positive rates of CTn and PTHR1 were not related to RET mutation, but the medium and strong positive rate of CTn ( 87. 5%) and PTHR1 (70. 8%) in RET mutant were higher than 25. 0% and 30. 0% of RET wild type (P＜0. 05). The expressions of CTn and PTHR1 were positively correlated with RET mutation(r＝0. 507 and 0. 364,P＜0. 05). Conclusion The enhanced expression of CTn and PTHR1 is related to the occurrence and development of SMTC, and the expression intensity of both is affected by RET mutation. The specific mechanism needs further study.