Increased SOCS1 and SOCS3 expression in papillary thyroid carcinoma and its association with prognosis

The majority of patients with papillary thyroid carcinoma (PTC) have good outcomes, although the identification of new predictors of a poor prognosis would be beneficial. Chronic thyroiditis is a precancerous condition in which proinflammatory cytokines enhance biologically aggressive features. This study investigated the expression of suppressor of cytokine signaling proteins (SOCS) 1 and 3, which are negative feedback inhibitors, in PTC and benign thyroid nodules (BTN), and analyzed the relations among biomarker expression, pathological prognosis, and clinical features.

The pathological materials and clinical data of 100 patients with PTC and 40 with BTN were retrospectively analyzed. Immunohistochemical SOCS1 and SOCS3 staining were performed. Besides comparing SOCS1 and SOCS3 expression between PTC and BTN, we analyzed the expression according to pathological factors and clinical variables.

The expression levels of the proteins were significantly higher in PTC than in BTN (p=0.001). SOCS1 expression was higher in older patients with PTC than in younger patients (p=0.001). Unlike SOCS1, SOCS3 was related to the risk group; these groups were distinguished based on the American Thyroid Association (ATA) risk stratification system (p=0.001). SOCS3 was also significantly related to lymph node involvement (p=0.007), capsule invasion (p=0.005), and extrathyroid extension (p=0.009).

The increased SOCS1 and SOCS3 expression in PTC confirms their roles in thyroid carcinogenesis. Antibodies to both SOCS1 and SOCS3 might aid the diagnosis of PTC through immunohistological staining. SOCS3 provides information on lymph node status and aids risk stratification.