SUPPORT FOR THYROID CANCER AND OTHER THYROID DISEASES IN BELARUS

该合同用于继续开展“白俄罗斯甲状腺癌和其他甲状腺疾病研究”，这是一项大规模的流行病学研究，旨在检测1986年4月26日切尔诺贝利核电站事故中暴露于辐射中的人的甲状腺和其他病理情况。这项研究涉及两个队列：(1)成立于1990年代末的“主要队列”，包括11,732名在事故发生时不满18岁或未满18岁的受试者，测量了他们对甲状腺的剂量，并居住在白俄罗斯切尔诺贝利受影响地区；(2)2017年设立的“子宫内队列”，包括2.965名在宫内和出生后早期接触切尔诺贝利放射性沉降物的人。这份合同的主要重点是在最近建立的宫内队列中进行甲状腺癌和疾病的医学筛查。主要队列在经历了三个周期的甲状腺筛查后，过渡到基于连锁的被动随访。 具体目标是：(1)对宫内人群进行甲状腺癌和甲状腺非癌症疾病的医学筛查；(2)评估以前重建的基于问卷的剂量的可靠性；(2)对主要人群和宫内人群：(3)通过与切尔诺贝利国家登记处和白俄罗斯国家癌症登记处的联系，保持被动后续行动，更新甲状腺癌、其他癌症和甲状腺非癌症疾病的发生情况；(4)通过邮寄调查更新人口、临床和流行病学数据。 宫内队列医学筛查的重点是甲状腺癌，但也确定了广泛的良性病变，包括良性肿瘤、结节、功能变化(甲亢或甲减、甲状腺炎等)，这些都与放射性碘暴露有关。这项研究的另一个重要方面是对基于问卷的剂量因记忆回忆而产生的不确定性进行评估。NCI之前的研究表明，如果研究对象有与剂量相关的测量，个人行为和饮食数据的质量通常对追溯剂量评估的结果影响很小。然而，只有大约15%的子宫内队列受试者的母亲可以直接测量甲状腺；由于可能的记忆回忆不良，评估剂量的不确定度对这项研究很重要。 合同的另一项任务是用由于与国家切尔诺贝利登记处和白俄罗斯国家癌症登记处建立记录联系而获得的信息，更新主要和子宫内队列的数据集。我们还通过邮寄调查更新主要队列对象的生命状况和最后已知地址。

The contract is for the continuation of the “Study of Thyroid Cancer and Other Thyroid Diseases in Belarus”, a large-scale epidemiological study detecting thyroid and other pathology in persons who have been exposed to radiation as released by the accident at the Chernobyl Nuclear Power Station in April 26, 1986. The study involves two cohorts: (1) the “main cohort” that was established in the late 1990s and consists of 11,732 subjects who were age 18 or under at the time of the accident, had their dose to the thyroid gland measured, and lived in the Chernobyl affected areas in Belarus; and (2) the “in utero cohort” that was established in 2017 and consists of 2.965 persons who were exposed to Chernobyl fallout radiation in utero and early post-natal life. The main emphasis of this contract is to conduct medical screening for thyroid cancer and diseases in the recently established in-utero cohort. The main cohort, after having undergone three cycles of thyroid screening, transitioned to linkage-based passive follow-up. The specific objectives are: for the in utero cohort, (1) to conduct medical screening for thyroid cancer and thyroid non-cancer disease; (2) to evaluate the reliability of questionnaire-based doses previously reconstructed; for both the main and in utero cohorts: (3) to maintain passive follow-up to update occurrences of thyroid cancer, other cancer and thyroid non-cancer disease, through linkage with the Chernobyl State Registry and the National Belarusian Cancer Registry, (4) update demographic, clinical and epidemiologic data through a mail survey. Medical screening of in utero cohort focuses on thyroid cancer but also ascertain a wide spectrum of benign lesions, including benign tumors, nodules, functional changes (hyper- or hypothyroidism, thyroiditis, etc.), which have been associated with radioiodine exposure. Another important aspect of the study is the evaluation of uncertainty of questionnaire-based doses due to memory recall. NCI’s previous study shows that if dose-related measurements are available for study subjects, the quality of individual behavior and dietary data has, in general, a small influence on the results of the retrospective dose assessment. However, direct thyroid measurements are available only for around 15% of mothers of in utero cohort subjects; evaluation of uncertainty in doses due to possibly poor memory recall is important for this study. Another task for the contract is to update the dataset for the main and in-utero cohort with information obtained as a result of record linkage to the State Chernobyl Registry and National Belarusian Cancer Registry. We are also updating vital status and last known address for the subjects of main cohort through a mail survey.