Association between BRAF (V600E) mutation and clinicopathological features of papillary thyroid carcinoma: a Brazilian single-centre case series

ABSTRACT Objectives: We aimed to investigate the prevalence of the BRAF (V600E) mutation in consecutive cases of papillary thyroid carcinoma (PTC) in patients diagnosed and treated at the Hospital Sao Rafael (Salvador, BA, Brazil) and evaluate its association with clinical and pathological characteristics of PTC. Subjects and methods: We retrospectively enrolled in the study a total of 43 consecutive PTC patients who underwent total thyroidectomy. We performed DNA extraction from formalin-fixed paraffin-embedded (FFPE) tumour tissue samples. Polymerase chain reaction (PCR) and direct sequencing were used to determine BRAF (V600E) mutation status. Univariate and multivariate logistic regression analyses were employed to identify independent associations. Results: The prevalence of BRAF (V600E) mutation was 65.1% (28/43). A high frequency of older patients (p value: 0.004) was observed among the BRAF-mutated PTC group and, in contrast, a low frequency of concurrent Hashimoto's thyroiditis (HT) (p value: 0.011) was noted. Multivariate analysis confirmed that older age (OR: 1.15; 95% CI: 1.00 – 1.33; p value: 0.047) and HT (OR: 0.05; 95% CI: 0.006-0.40; p value: 0.005) were independent factors associated with BRAF (V600E) mutation. Conclusion: We found a high prevalence of BRAF (V600E) mutation in PTC cases. Older age and no concurrent HT were independently associated with BRAF (V600E) mutation.摘要 研究目的：本研究旨在调查巴西巴伊亚州萨尔瓦多市圣拉斐尔医院（Hospital Sao Rafael）收治的连续性甲状腺乳头状癌（papillary thyroid carcinoma, PTC）患者中BRAF（V600E）突变的检出率，并评估该突变与PTC临床及病理特征的相关性。 研究对象与方法：本研究回顾性纳入43例接受全甲状腺切除术的连续性甲状腺乳头状癌患者。从福尔马林固定石蜡包埋（formalin-fixed paraffin-embedded, FFPE）肿瘤组织样本中提取基因组DNA，采用聚合酶链反应（polymerase chain reaction, PCR）及直接测序法检测BRAF（V600E）突变状态。通过单因素及多因素logistic回归分析，明确与该突变相关的独立影响因素。 研究结果：BRAF（V600E）突变检出率为65.1%（28/43）。BRAF突变型PTC组中高龄患者占比显著更高（P=0.004），而合并桥本甲状腺炎（Hashimoto's thyroiditis, HT）的患者占比显著更低（P=0.011）。多因素分析证实，高龄（比值比OR=1.15；95%置信区间CI：1.00~1.33；P=0.047）以及未合并桥本甲状腺炎（OR=0.05；95%CI：0.006~0.40；P=0.005）为与BRAF（V600E）突变独立相关的因素。 研究结论：本研究发现甲状腺乳头状癌患者中BRAF（V600E）突变检出率较高，高龄与未合并桥本甲状腺炎均为BRAF（V600E）突变的独立相关因素。