The study cohort includes all those who were resident in the areas of Ukraine and Russia contaminated by radioactive fallout from the accident and who were aged under 19 at exposure (i.e. born after 26th April 1967). Thyroid cancer in those who were children or adolescents at exposure is the only cancer to have shown a substantial increase in these areas and it is clearly related to exposure to radioiodine (predominantly the short lived isotopes â€“ particularly 131I, which has a half life of 8.1 days). This is evidenced by the sharp decrease in the frequency of thyroid cancer (returning to pre-accident levels) in those who were born after 1/1/87 and were therefore not exposed to radioiodine either in utero (the thyroid concentrates iodine from 3 months of intrauterine age) or in childhood. The cohort now includes a significant number of cases of thyroid tumours from patients who are resident in the areasÂ contaminated by fallout from Chernobyl, but by virtue of the fact that they were born after 1/1/87 have not been exposed to radioiodine.Â This is an extremely valuable cohort that serves as a control population for thyroid cancer associated with radioiodine exposure.
The CTB collects a variety of different types of biospecimen from patients undergoing operations for thyroid cancer or adenoma in the Institute of Endocrinology and Metabolism in Kiev, Ukraine and the A. TsybÂ Medical Radiological Research Centre in Obninsk, Russian Federation who consent to donate to the project. Tissue is collected to an approved standard operating procedure (SOP) and is snap frozen; the presence or absence of tumour is verified by frozen section. A representative paraffin block is also obtained for each case. Where appropriate, we also collect fresh and paraffin-embedded tissue from loco-regional metastases.
Histological slides from all tumours are reviewed by the CTB Pathology Panel - an international group of expert thyroid pathologists, and a consensus diagnosis agreed before any materials are released to researchers.
The CTB provides materials and data to research groups worldwide. The aim of the project is to ensure that the maximum amount of information can be gathered from what is a unique and limited resource. The surgical samples of thyroid tissue are generally small, therefore the CTB does not currently Â issue tissue, but provides extracted nucleic acids, paraffin sections and sections from tissue microarrays prepared from this material. Researchers are required to return research data to the CTB Data Warehouse so that the information can be shared with other researchers and could lead to better patient care and assessment of risk from radiation exposure to a young population in the future.
For information on how you can apply to access biomaterials or research data click here.
The on-line application process allows a potential applicant to review whether samples or data matching the researcherâ€™s search criteria are available in the CTB. The table below provides a summary of the cumulative total of cases from Ukraine and the Russian Federation, which have been reviewed by the Pathology Panel and a consensus diagnosis agreed; the number of cases for which frozen material is available is given in brackets.
|Papillary Carcinoma (incl micro PTC)||2018||(1549)||908||(673)||2926||(2222)|
Other thyroid cancers
Other Benign Follicular Tumours
|Miscellaneous Thyroid TumoursÂ
(Other and Nodule, TTT)
Table updated 1stÂ February 2017
The total number of cases included in the CTB from Ukraine and Russia is 4500. Of these 69% are resident in the contaminated oblasts and 83% of these were born beforeÂ 1stÂ December 1986 and therefore exposed to radioiodine at 3 months of intrauterine age or older. A total of 17% were born after 1stÂ December 1986Â and therefore not exposed to radioiodine in fallout.