Department of Endocrinology, University of Pisa, Via Paradisa 2, Pisa, Italy.
J Endocrinol Invest. 2012;35(6 Suppl):3-9.
Differentiated thyroid cancer (DTC) represents 1-2% of all human malignancies. The annual incidence varies among countries and it is estimated that 1.2-2.6 men and 2.0-3.8 women/100,000 individuals are affected worldwide. This incidence has been increasing in the last decades, likely due to an "over-diagnosis" of small cancers that would have remained occult and that have been likely revealed because of an increased diagnostic scrutiny rather than a real increase of incidence. The annual mortality rate for DTC is 0.5/100,000 both in men and women. DTC is 2-4 times more frequent in females than in males. The mean age at diagnosis is 40-45 yr for papillary tumors (PTC) and 50-55 yr for follicular tumors (FTC). They are very rare in children. Ninety percent of DTC are represented by PTC hystotype, mainly follicular and classical variants. In the last years it has been observed an important change in the oncogenic pattern of PTC with a significant reduction of RET/PTC rearrangements and an increase of BRAFV600E mutation suggesting a change in pathogenic events. The unique well-demonstrated risk factor of DTC is the exposure to external radiation which is also correlated with the presence of RET/PTC rearrangements. Recently, other environmental factors (i.e. living in a volcanic area or in a iodine- either deficient or rich area) or some eating habits leading to obesity have been considered as potential DTC risk factors. However, at present, the favorite hypothesis is that a complex interaction between genetic and environmental factors is required to develop DTC.
分化型甲状腺癌（DTC）占人类恶性肿瘤的 1-2%。其发病率在各国之间存在差异，据估计，全世界每年有 1.2-2.6 名男性和 2.0-3.8 名女性/10 万人受到影响。在过去几十年中，这种发病率一直在增加，这可能是由于对原本隐匿且可能因诊断检查增加而被发现的小癌症的“过度诊断”所致，而不是发病率的真正增加。DTC 的年死亡率在男性和女性中均为 0.5/10 万。DTC 在女性中的发病率是男性的 2-4 倍。乳头状癌（PTC）和滤泡状癌（FTC）的平均诊断年龄分别为 40-45 岁和 50-55 岁。它们在儿童中非常罕见。90%的 DTC 是由 PTC 组织学类型代表，主要是滤泡状和经典型。近年来，PTC 的致癌模式发生了重要变化，RET/PTC 重排明显减少，BRAFV600E 突变增加，提示发病机制发生了变化。DTC 唯一明确的危险因素是暴露于外源性辐射，这也与 RET/PTC 重排的存在相关。最近，其他环境因素（如生活在火山地区或碘缺乏或丰富的地区）或一些导致肥胖的饮食习惯也被认为是潜在的 DTC 危险因素。然而，目前，人们普遍认为，遗传和环境因素之间的复杂相互作用是导致 DTC 发生的必要条件。
