Nagataki Shigenobu, Nyström Ernst
Nagasaki University School of Medicine, Nagasaki, Japan.
Thyroid. 2002 Oct;12(10):889-96. doi: 10.1089/105072502761016511.
The purpose of this review is to provide an account of our present knowledge about the epidemiology of nonmedullary thyroid carcinoma, to discuss the effects of environment, lifestyle and radiation on the risk of developing thyroid cancer, and to discuss aspects on primary prevention of the disease. In areas not associated with nuclear fallout, the annual incidence of thyroid cancer ranges between 2.0-3.8 cases per 100,000 in women and 1.2-2.6 per 100,000 in men, women of childbearing age being at highest risk. Low figures are found in some European countries (Denmark, Holland, Slovakia) and high figures are found in Iceland and Hawaii. Differences in iodine intake may be one factor explaining the geographic variation, high iodine intake being associated with a slightly increased risk of developing thyroid cancer. In general, lifestyle factors have only a small effect on the risk of thyroid cancer, a possible protective effect of tobacco smoking has been recently reported. Because of the (small) increase in risk of thyroid cancer associated with iodination programs, these should be supervised, so that the population does not receive excess iodine. The thyroid gland is highly sensitive to radiation-induced oncogenesis. This is verified by numerous reports from survivors after Hiroshima and Nagasaki, the Nevada, Novaja Semlja and Marshal Island atmospheric tests, and the Chernobyl plant accident, as well as by investigations of earlier medical use of radiation for benign diseases in childhood. These reports are summarized in the review. There appears to be a dose-response relation for the risk of developing cancer after exposure to radioactive radioiodine. The thyroid gland of children is especially vulnerable to the carcinogenic action of ionizing radiation. Thus, the incidence of thyroid cancer in children in the Belarus area was less than 1 case per million per year before the Chernobyl accident, increasing to a peak exceeding 100 per million per year in certain areas after the accident. It is a social obligation of scientists to inform the public and politicians of these risks. All nuclear power plants should have a program in operation for stockpiling potassium iodide for distribution within 1-2 days after an accident.
本综述的目的是阐述我们目前对非髓样甲状腺癌流行病学的认识，讨论环境、生活方式和辐射对甲状腺癌发病风险的影响，并探讨该疾病一级预防的相关方面。在与核沉降无关的地区，甲状腺癌的年发病率在女性中为每10万例2.0 - 3.8例，在男性中为每10万例1.2 - 2.6例，育龄女性风险最高。一些欧洲国家（丹麦、荷兰、斯洛伐克）的发病率较低，而冰岛和夏威夷的发病率较高。碘摄入量的差异可能是解释这种地理差异的一个因素，高碘摄入与甲状腺癌发病风险略有增加有关。一般来说，生活方式因素对甲状腺癌风险的影响较小，最近有报道称吸烟可能具有保护作用。由于碘化计划与甲状腺癌风险的（微小）增加有关，应对其进行监管，以免人群摄入过量碘。甲状腺对辐射诱导的肿瘤发生高度敏感。广岛和长崎原子弹爆炸幸存者、内华达、新地岛和马绍尔群岛大气层核试验以及切尔诺贝利核电站事故的众多报告，以及对儿童时期因良性疾病而早期接受放射治疗的调查都证实了这一点。这些报告在综述中进行了总结。暴露于放射性碘后发生癌症的风险似乎存在剂量反应关系。儿童的甲状腺尤其易受电离辐射致癌作用的影响。因此，切尔诺贝利事故前白俄罗斯地区儿童甲状腺癌的发病率每年低于百万分之一例，事故后某些地区增至每年超过百万分之一百例的峰值。向公众和政治家通报这些风险是科学家的社会义务。所有核电站都应实施一项计划，储备碘化钾以便在事故发生后1 - 2天内进行分发。
