Molecular epidemiology of radiation induced thyroid cancer

据报告，在儿童时期受到1986年切尔诺贝利核事故高剂量放射性沉降物影响的人中，甲状腺癌发病率大幅增加。切尔诺贝利组织库是一个国际支助的项目，确保为适当的研究提供材料（冷冻组织、固定组织切片、提取的DNA/RNA和血液样本）。到目前为止，已经登记了2,500多个病例，CTB保存了280多个甲状腺肿瘤的DNA和RNA，这些肿瘤来自爆炸时19岁以下的患者。尽管切尔诺贝利周围人口中95%以上的癌症被归类为乳头状癌，但它们的形态各不相同，从固体不成熟表型，以乳头状或滤泡状结构为主的分化良好的肿瘤。一些关于切尔诺贝利周围甲状腺癌的早期报告表明，实体形态，侵袭性， ...更多信息 RET/PTC 3重排频率明显增高提示放射源性肿瘤。然而，最近的研究表明，乳头状癌的形态学模式是随着潜伏期的增加而改变的。我们发现，与潜伏期较长的肿瘤相比，短潜伏期与实体形态和显著更具侵袭性的扩散相关。相反，分化的类型与暴露时的年龄有关。许多报告表明，RET/PTC 3重排与短潜伏期肿瘤中所见的实体形态相关，而分化良好的乳头状癌更常显示RET/PTC 1重排。BRAF突变的频率在切尔诺贝利后甲状腺癌中较低，与其他儿童甲状腺乳头状癌研究中观察到的相似，这可能与患者诊断时的年龄有关。最近的研究表明，来自乌克兰和俄罗斯的未暴露肿瘤组与来自同一地区的暴露肿瘤在形态上基本相同。日本儿童的肿瘤与切尔诺贝利周围的肿瘤有显著的不同，无论是暴露的还是未暴露的，都显示出明显更多的分化，更多的乳头状分化。一个值得认真考虑的可能性是饮食中的碘含量。少

A large increase in thyroid carcinoma incidence among those exposed as children to the high levels of fallout from the nuclear accident at Chernobyl in 1986 has been reported. The Chernobyl Tissue Bank (CTB) is an internationally supported project and ensures that materials (frozen tissue, fixed tissue sections, extracted DNA/RNA and blood samples) are available for appropriate research studies. Up to date more over 2,500 cases have been registered, and the CTB holds DNA and RNA from more than 280 thyroid tumors from the patients younger than 19 at the time of the explosion.Although over 95% of the cancers are classified as papillary carcinomas in the population around Chernobyl following exposure to fallout, they vary in their morphology, ranging from a solid immature phenotype, to well differentiated tumors dominated by either papillary or follicular architecture. Some of the early reports on the thyroid carcinomas around Chernobyl suggested that the solid morphology, aggressiveness, … More and the apparently high frequency of RET/PTC3 rearrangements were indicative of radiogenic tumors. However, recent studies have shown that the morphological pattern of papillary carcinomas is changing with increasing latency. We showed that short latency is associated with solid morphology and significantly more invasive spread when compared to tumors with a longer latent period. In contrast, the type of differentiation is associated with age at exposure. Many reports have suggested that RET/PTC3 rearrangements are associated with the solid morphology seen in short latency tumors, while well diffrentiated papillary carcinomas more often show RET/PTC1 rearrangements. The frequency of BRAF mutation is low in post Chernobyl thyroid cancer and is similar to that observed in other studies of childhood thyroid papillary carcinoma, and this may be related to the age of the patient at diagnosis. More recent study revealed that the unexposed group of tumors from Ukraine and Russia were essentially identical morphologically to the exposed tumors from the same area. The tumors from Japanese children were significantly different from the tumors from around Chernobyl, whether exposed or unexposed, showing significantly more differentiation, more papillary differentiation. One possibility deserving serious consideration is the iodine content of the diet. Less