BRAF突变型甲状腺微小乳头状癌的侵袭性

Invasiveness of Papillary Thyroid Microcarcinoma with BRAF Mutation

目的研究BRAF突变型甲状腺微小乳头状癌(PTMC)的侵袭性。方法在131I治疗前综合评估中,选择99例甲状腺全切术后BRAF突变型PTMC,同时纳入97例肿块大于1cm的BRAF突变型甲状腺乳头状癌(PTC)进行比较,分析其局部及远处侵袭性,如淋巴结转移、甲状腺外侵犯及远处转移等与预后及复发风险相关的指标。结果 PTMC组甲状腺外侵犯率达16.10%,颈部淋巴结转移率达71.74%;直径≤0.3cm组、0.3cm<直径≤0.6cm组和0.6cm<直径≤1.0cm组的颈部淋巴结转移率分别为60.00%、72.50%和73.81%,甲状腺外侵犯率分别为10.00%、9.09%和24.44%,肿瘤多灶率分别为60.00%、38.64%和57.78%;单因素分析结果显示,肿块大小与PTMC的肿瘤多灶性(χ2=3.752,P=0.153)、颈部淋巴结转移(χ2=0.780,P=0.677)、甲状腺外侵犯(χ2=4.182,P=0.124)及远处转移(χ2=1.212,P=0.545)均没有明显相关性。PTMC和PTC组在肿瘤多灶性方面差异没有统计学意义(χ2=1.742,P=0.187),在甲状腺外侵犯(χ2=13.000,P=0.000)、颈部淋巴结转移(χ2=12.819,P=0.000)和远处转移(χ2=5.316,P=0.021)方面差异有统计学意义;多因素Logistic回归分析结果显示,PTC组与PTMC组与肿块大小密切相关的因素包括颈部淋巴结转移(P=0.001)及甲状腺外侵犯(P=0.003);PTMC组和PTC组的甲状腺外侵犯率分别为16.10%和39.18%,颈部淋巴结转移率分别为71.74%和91.75%,远处转移率分别为1.01%和9.28%。结论 BRAF突变型PTMC伴有较高的淋巴结转移和甲状腺外侵犯能力,并表现出与PTC相似的多灶性侵袭性。当BRAF突变型PTMC伴有甲状腺外侵犯或淋巴结转移等危险因素时,应给予131I治疗。

Objective To explore the invasiveness of papillary thyroid microcarcinoma （PTMC） with BRAF mutation. Methods Totally 99 patients with FFMC with BRAF mutation were enrolled in this study, meanwhile another 97 patients with papillary thyroid carcinoma （FFC） （ tumor size 〉 1 cm） with BRAF muta- tion were included as controls. The clinicopathologic factors including extrathyroidal invasion, multifocality, anddistant metastasis were analyzed. Results The rates of extrathyroidal invasion and nodal metastasis in PTMC group were as high as 16. 10% and 71.74% , respectively. In the PTMC group and PTC group, the extrathy- roidal invasion rate was 16.10% and 39.18%, cervical lymph node metastasis rate was 71.74% and 91.75% , and distant metastasis rate was 1.01% and 9.28% , respectively. In the PTMC subgroups with tumor sizes ~〈0.3 era, 0.3-0.6 era, and 0.6-1.0 cm, the cervical lymph node invasion rate was 60.00% , 72.50% , and 73.81% , the extrathyroidal invasion rate was 10.00% , 9.09% , and 24.44% , and the multifocality rate was 60.00% , 38.64% , and 57.78% , respectively. Univariate analysis showed that the tumor size was not significantly correlated with muhifocality （）（2 = 3. 752, P = 0. 153 ） , cervical lymph node metastasis （X2 = 0. 780,P = 0. 677） , extrathyroidal invasion （X2 = 4. 182, P = 0. 124） , and distant metas- tasis （X2 = 1. 212, P = 0. 545 ） . While the BRAF group and PTC group were not significantly different in muhifocality （X2 = 1. 742, P = 0. 187 ） , they were significantly different in terms of extrathyroidal invasion （X2 = 13. 000, P =0. 000）, nodal involvement （X2 = 12. 819, P = 0. 000）, and distant metastasis （X2 = 5.316, P = 0.021 ） . Multivariate analysis showed that nodal metastasis was independently associated with size 〉 1 cm （ P = 0.001 ） and extrathyroidal invasion （ P = 0. 003 ） . Conclusions BRAF mutant PTMC manifests relative high extrathyroidal involvement and nodal metastasis, and the similar multifocality as BRAF mutant PTC. Radioactive iodine should be considered in PTMC with the presence of BRAF mutation combined with extrathyroidal invasion or nodal metastasis.