Effect and Interactions of BRAF on Lymph Node Metastasis in Papillary Thyroid Carcinoma With Hashimoto Thyroiditis

CONTEXT: The role of B-Raf proto-oncogene (BRAF) in papillary thyroid carcinoma (PTC) with Hashimoto thyroiditis (HT) is unknown. OBJECTIVE: We aimed to explore risk factors affecting lymph node (LN) metastasis and interaction effect of BRAF in PTC patients with HT. METHODS: We retrospectively collected the data of 994 PTC patients with HT who underwent surgery at the West China Hospital. We analyzed the correlations between preoperative characteristics and LN metastasis in overall, and different BRAFV600E-mutation patients. Logistic regression was applied to analyze the risk factors for LN metastasis. Finally, we performed an interaction effect analysis to identify the interaction effect of BRAF. RESULTS: The overall LN metastasis rate was 52.71% (524/994); the overall BRAF mutation rate was 26.9% (268/994). BRAF mutation rates were significantly different in LN metastasis and nonmetastasis patients (31.7% vs 21.5%; P < .001). In all 994 patients, age, body mass index (BMI), hypertension, tumor maximum diameter, BRAF mutation, tumor location, aspect ratio, calcification, and extrathyroidal invasion were risk factors for LN metastasis (P < .05). In BRAF-mutant patients, smoking, hypertension, maximum diameter, calcification, and multifocality were risk factors for LN metastasis (P < .05). In BRAF wild-type patients, age, BMI, maximum diameter, tumor location, aspect ratio, tumor shape, calcification, and extrathyroidal invasion were risk factors (P < .05). Additionally, we found statistically significant interactions between BRAF and BMI, hypertension, maximum diameter, and calcification (P < .05), suggesting the potential interaction effect of BRAF. CONCLUSION: BRAF is a risk factor for LN metastasis in PTC with HT. Meanwhile, BRAF can interact with age, BMI, hypertension, and calcification, which together influence LN metastasis.