Introduction to the project
The CTB (Chernobyl Tissue Bank) is a unique venture. It is the first international cooperation that seeks to establish a collection of biological samples from tumours and normal tissues from patients for whom the aetiology of their disease is known - exposure to radioiodine in childhood. The project, which started in October 1998, has been supported by a number of sponsors including the European Commission, the WHO, the National Cancer Institute (NCI) of the USA and the Sasakawa Memorial Health Foundation of Japan (SMHF). The project is currently jointly funded by the NCI and the SMHF. The project is coordinated from Imperial College, London and works with Institutes in the Russian Federation (the Medical Radiological Research Centre in Obninsk) and Ukraine (the Institute of Endocrinology and Metabolism in Kiev) to support local scientists and clinicians to manage and run a tissue bank for those patients who have developed thyroid tumours following exposure to radiation from the Chernobyl accident. Belarus was also initially included in the project, but is currently suspended for political reasons.
The project has the full support of the Governments of the Russian Federation and Ukraine.
The large number of thyroid tumours that have occurred in areas exposed to high levels of fallout from the Chernobyl accident raises important problems in the areas of public health, regulation of exposure to radionuclides and in the understanding of the molecular changes involved in their genesis. The over-riding priority must go to matters such as diagnosis, treatment of those affected, and prevention. International Agencies have given and are giving financial and material help in these areas. However, providing the needs of the patient are not compromised, it is very important to ensure that information that may be of value to the health of future generations is not lost. Although the post Chernobyl thyroid tumours are associated with a particular aetiology, they may also provide clues to the pathogenesis and molecular biology of thyroid carcinoma in general.
Aims of the project
The main objective of this project is to provide a research resource for both ongoing and future studies of the health consequences of the Chernobyl accident. It seeks to maximize the amount of information obtained from small pieces of tumour by providing multiple aliquots of RNA and DNA extracted from well documented pathological specimens to a number of researchers world-wide and to conserve this valuable material for future generations of scientists. It exists to promote collaborative, rather than competitive, research on a limited biological resource. The project:
• ensures that the best possible diagnostic service is provided to patients and that appropriate ethical consent is obtained for each biological sample
• ensures that specimens of thyroid cancer operated on or after 1st October 1998 (the start date of the project) are properly described and sampled, and that materials (frozen tissue, fixed tissue sections, extracted DNA/RNA and blood samples), are available for appropriate research studies
• provides a diagnosis agreed by internationally recognized pathologists. The diagnosis is made available to research groups carrying out molecular biological, therapeutic, epidemiological and other studies
• provides an archive of data generated from research studies carried out using the material that can be used for future studies on the interaction of specific oncogenic changes in the generation of radiation related thyroid cancer. This may have direct relevance to both prognosis and assessment of risk from exposure to radiation
The project is already achieving the first three objectives above, but continued collection of material is necessary for a number of reasons. There is evidence that suggests that tumours following a short latency are likely to show a different molecular biological and pathological profile than those of a longer latency; this project will help to clarify this difference as the latent period since the accident increases. Thyroid cancer is increasing world-wide and although most tumours do not have a defined radiation aetiology, it is likely that the insights gained from studying the post Chernobyl tumours will provide information that could be of use for the diagnosis and treatment of thyroid cancer and of other cancers in general.
What happens to the results of the research studies?
Researchers who obtain material from the CTB agree to provide the results of their investigation on a case-by-case basis. This information will not be used until after the researchers have published their findings, but it will allow the results of all of the studies to be correlated at a later date, so that, for example, the investigations by different groups of a number of different genes can be correlated to study their interactions. The provision of extracted nucleic acid from thyroid tissue, rather than each researcher being provided with a small piece of tissue maximises the amount of data that can potentially be obtained from a single operative specimen and will enable multiple molecular biological studies to be carried out for each case.
Through the CTB Portal, researchers wishing to access the resources of the CTB can apply a number of search criteria to see what biomaterials and research data are available which match the requirements for their study, before submitting an application to access the samples.
Where is the CTB located?
The tissue banks are situated in two of the countries most exposed to fallout from Chernobyl; one at the Institute of Endocrinology and Metabolism in Kiev, Ukraine and one at the Medical Radiological Research Centre of the Russian Ministry of Health and Social Development in Obninsk in the Russian Federation. Each Bank consents patients and prepares and stores material from its own population. The institute's record information about cases recruited for the CTB in a central data warehouse housed on secure servers at Imperial College, London. Each institute has access to the complete data from its own population at any time and researchers whose projects have been approved for access to the resources of the CTB can access a defined dataset (detailed below) for the relevant cases on-line.
The CTB includes material and information from all patients with thyroid carcinomas and cellular follicular adenomas from the contaminated oblasts of the Russian Federation (Bryansk, Kaluga, Tula and Oryol) and Ukraine (Kiev, Kiev city, Cherkasse, Chernigov, Rovno, Zhitomyr and Sumy) who were born after 26th April 1967 (i.e. aged under 19 at the time of the Chernobyl accident) and operated on or after the 1st October 1998. Detailed standard operating procedures for the collection and documentation of specimens and blood samples have been agreed with professional staff involved in the collection of material, and ethical standards agreed upon with the relevant authorities, conforming to the requirements of each country involved, including those of the funding organisations. Standard operating procedures for collection of information and material have been approved by the relevant Ethical Committees. Each specimen is given a code authorized by the appropriate person responsible for the management of the resource in each of the three countries. The age, sex, date of birth, date of operation, oblast and country of residence and a calculated figure for the dose received are recorded for each specimen stored in the CTB, and are made available to researchers with approved projects receiving material from the bank. Information enabling researchers to identify an individual patient (e.g. name, address etc) is stored separately and password protected, in the Institutes in Ukraine and Russia and is not available to researchers. Details of the methodology used to calculate the dose are also available to researchers.