遗传性甲状腺癌诊治要点

Key points of diagnosis and treatment of hereditary thyroid cancer

随着甲状腺癌的高发,遗传性甲状腺癌也愈受关注。主要分为遗传性髓样癌和家族性非髓样甲状腺癌。前者主要由RET基因胚系突变所致,是多发性内分泌肿瘤2型的重要组成部分。根据突变位点不同,在婴幼儿期预防性全甲状腺切除可避免甲状腺髓样癌的发生,但需平衡疾病进展和手术并发症风险之间的利弊。密切监测血清降钙素水平,发现升高不应再推迟手术,基本术式为全甲状腺切除加双侧中央区清扫术,必要时行治疗性或预防性侧颈淋巴结清扫。后者是指在没有易感环境因素的情况下,家族一级亲属间有≥2例的非髓样甲状腺癌病人,其中少数以综合征形式存在,有已知的基因改变,大多数是非综合征形式的分化型甲状腺癌,可能是单基因或多基因的低外显率的常染色体显像遗传,多数报道较散发病例更具侵袭性,需要更积极的治疗。

With the increasing prevalence of thyroid cancer,hereditary thyroid cancer has been noted more.It includes two parts:hereditary medullary carcinoma(HMTC)and familial non-medullary thyroid cancer(FNMTC). HMTC is mainly caused by germline mutations in the RET gene and is an important component of multiple endocrine neoplasia type 2.Depending on the mutation site, prophylactic total thyroidectomy in infancy is advised to prevent the development of medullary thyroid cancer,but the risk of surgical complications should be considered seriously. The intervention could not be delayed if the serum calcitonin levels elevates. Total thyroidectomy with bilateral central dissection is the basic procedure,and therapeutic or prophylactic lateral cervical lymph node dissection is necessary at certain times.FNMTC occurs in two or more first-degree relatives in the absence of predisposing environmental factor. Out of all FNMTC cases, only 5% are represented by syndromic forms,in which thyroid cancer occurs as a minor component and the genetic alterations are well-known. The non-syndromic forms represent the majority of all FNMTCs, and the thyroid cancer is the predominant feature. Several low penetration susceptibility risk loci or genes in autosomal dominant have been proposed in recent years with a possible causative role.Non-syndromic FNMTC is usually be thought to be more aggressive than the sporadic differentiated thyroid cancer and requires more active treatment.