Analysis of BRAF Gene Mutation in Hashimoto's Thyroiditis With Multifocal Papillary Thyroid Carcinoma

Background: Thyroid cancer (TC) is a highly prevalent malignant tumor of the head and neck. Papillary thyroid carcinoma (PTC) is the primary pathological type of TC, accounting for more than 80% of all TCs. BRAF mutations are closely associated with PTC. However, the relationship among HT, PTC, and BRAF mutations has not yet been clarified. We aimed to investigate the BRAF mutation in Hashimoto's thyroiditis (HT) with PTC. Methods: A total of 72 patients with multifocal PTC were included and grouped based on surgical pathology examination. Group A (n = 32) had pure multifocal PTC and Group B (n = 40) had HT with multifocal PTC. Various features were compared: BRAF mutation, multifactorial analysis of BRAF mutations, pathological features in patients with HT and multifocal PTC, and multifactorial analysis of factors affecting HT with multifocal PTC. Results: Significant differences were seen in thyroid peroxidase antibody levels, central lymph node metastasis, extra-thyroidal invasion, main and non-main lesion diameters, and BRAF mutation positivity (P < 0.05). Patients with the BRAF mutation had significantly higher rates of extra-thyroidal invasion and lymph node metastasis than those without the BRAF mutation (P < 0.05). Logistic regression analysis showed that BRAF mutation and main lesion nodule diameter were independent risk factors affecting extra-thyroidal invasion and central lymph node metastasis in patients with HT and multifocal PTC (P < 0.05). Discussion: BRAF mutations were more prevalent and closely associated with extra-thyroidal invasion and central lymph node metastasis in patients with HT and multifocal PTC.