Thyroid stimulating hormone levels and BRAFV600E mutation contribute to pathophysiology of papillary thyroid carcinoma: Relation to outcomes?

The aim of this study was to evaluate the relation between the level of thyroid stimulating hormone (TSH) and progression of papillary thyroid carcinoma (PTC) with or without BRAFV600E mutation.The medical records and laboratory data of 547 patients with PTC and 94 patients with follicular adenoma (FA) were collected. The relationship between hormones levels and such end-points as extrathyroid extension (ETE), lymphovascular invasion (LVI) and lymph node metastasis (LNM) was assessed. In addition, age, gender, BRAFV600E mutation status, histological type and Hashimoto's thyroiditis (HT) were considered.Most of the patients with PTC had hormones levels within the normal range, however, serum TSH concentration was significantly higher in PTC comparing with FA (P = 0.022). High levels of TSH in PTC were more frequent among women rather than men (P = 0.03) due to the gender differences in coexisting HT rate (P = 0.003). In contrast, LNM rate was higher in men (P = 0.0014). Coexisting HT significantly decreased the risk of ETE (OR = 0.67; 95%CI 0.44-1.00; P = 0.05) and LNM (OR = 0.59; 95%CI 0.37-0.94; P = 0.028) among males with PTC. However, there was no significant relationship between HT and PTC-related ETE and LNM in females. BRAFV600E mutation was associated with presence of lymphocytic infiltration (P < 0.001) but not with HT (P = 0.08) and violation of thyroid function.The present study showed the lack of significant relationship between TSH levels and PTC aggressiveness (LNM, TNM stage, BRAFV600E mutation). Higher TSH levels were found in patients with coexisting HT that was associated with female sex and multifocality of PTC.