To investigate the expression changes of SLeX and Gal-3 in papillary thyroid carcinoma (PTC) and the relationship with clinicopathologic parameters.

A retrospective study of 120 continuous patients with PTC who underwent resection from May 2017 to December 2020 was conducted. The expressions of SLeX and Gal-3 were detected in 120 pieces of primary PTC tissue and 30 pieces of adjacent carcinoma tissue by EliVision^TM plus two-step immunohistochemical method. The relationships between the expressions of SLeX and Gal-3 and the clinicopathologic parameters including patient age, TI-RADS grading, TNM staging,carcinomatous infiltration, lymph node metastasis were studied.

The differences of positive rates of SLeX and Gal-3 between primary PTC tissue (67.5%, 90.8% respectively) and adjacent carcinoma tissue (6.7%, 16.7% respectively) were statistically significant (both P<0.001). The expressions of SLeX had not statistically significant in the groups of different ages. The SLeX expression significantly correlated with the TI-RADS grading, TNM stages, carcinomatous infiltration, lymph node metastasis (all P<0.05). The expressions of Gal-3 had not statistically significant in the groups of different ages, TI-RADS grading, TNM stages. The Gal-3 expression significantly correlated with the carcinomatous infiltration, lymph node metastasis (both P<0.05). The rate of both positive expressions was 65.8%, and both negative expressions was 7.5%. There was a positive correlation between the expressions of SLeX and Gal-3 in PTC tissue (r=0.32, P<0.05).

The up-regulated SLeX expression may hint high TI-RADS grading and late TNM stages. High-level expressions of SLeX and Gal-3 in PTC are closely correlated with the progress of carcinomatous infiltration and lymph node metastasis.