Clinical Significance Of Subtilisin-LikeProprotein Convertase 4 In IdentifyingThyroid Nodules

ObjectivesThe purpose of this study was to compare the expression distribution of SPC4-F and SPC4-C subtypes in benign and malignant thyroid nodules,and to provide reference data for their identification as biological markers of benign and malignant thyroid nodules.MethodsThyroid tissue blocks of patients undergoing thyroidectomy from 2011 to2020 were searched from the Pathology Department of our hospital,and classified according to the final pathological classification.The corresponding tissue sections were immunostained using the full length SPC4 protein(SPC4-F)and its replacement subtype(SPC4-C).The nodule was compared with adjacent normal tissue and immunohistochemical staining was evaluated by two experienced pathologists.ResultsNo or low expression of SPC4-F was found in non-diseased thyroid tissues(including normal tissue and benign lesions)by immunohistochemistry.(P<0.01).The expression rate of SPC4-F in malignant nodule group was 52.9%,4.2%(P<0.01).The specificity of SPC4-F immunostaining was 95.8%(95%CI,78.9%~99.9%).In malignant lesions,the expression of SPC4-F protein is most pronounced in typical papillary carcinomas,showing overexpression of immunostaining in apical distribution.In contrast,immunostaining of follicular papillary carcinoma showed low expression.In follicular carcinomas,60% showed immunostaining overexpression,especially in the eosinophilic region of the nodules.In benign nodule,the expression of SPC4-C in thyroid parenchyma of lesion and non-lesion(normal)was similar(P >0.05).However,in malignant nodules,SPC4-C expression in the lesion area was significantly lower than that in the adjacent non-lesion area(P<0.05).ConclusionsIn this study,SPC4-F is a promising biomarker for the detection of thyroid cancer because the discovery of high and low specific expression of SPC4-F and SPC4-C in thyroid malignancies.