THYROID CANCER INCIDENCE IN THE POPULATION OF UKRAINE AND ITS EPIDEMIOLOGICAL DETERMINANTS: IONIZING RADIATION AND ENDOCRINE DISRUPTORS.

Objective: to estimate the risk of thyroid cancer incidence in the population of Ukraine in connection with its exposure to radioactive iodine fallout of Chornobyl origin and the use of pesticides in agricultural production in the country.

Object Of Study: Incidence rates of thyroid cancer in the population of Ukraine in 2001-2019, average regional radiation doses absorbed by the thyroid because of the Chornobyl accident, the volume of use of various groups of pesticides in the regions of Ukraine.

Research Methods: statistical, mathematical and cartographic.

LATE ONCOLOGICAL AFTEREFFECTS OF RADIATION EXPOSURE CAUSED BY THE CHORNOBYL ACCIDENT.

Studies of the longterm oncological consequences after the Chornobyl accident show a significant impact of radiation exposure on the cancer incidence rate in affected population in Ukraine. This is supported by the increased radiation risk of leukaemia in liquidators, which exceeds national population rates, and its value is comparable to the data on hibakushi, who were subjected to Abombings. For the first time in the cleanup workers cohort the radiation dependence of chronic lymphoid leukaemia was established.

Impact of uncertainties in exposure assessment on thyroid cancer risk among cleanup workers in Ukraine exposed due to the Chornobyl accident.

A large excess risk of thyroid cancer was observed among Belarusian/Russian/Baltic Chornobyl cleanup workers. A more recent study of Ukraine cleanup workers found more modest excess risks of thyroid cancer. Dose errors in this data are substantial, associated with model uncertainties and questionnaire response.

Lack of transgenerational effects of ionizing radiation exposure from the Chernobyl accident.

Effects of radiation exposure from the Chernobyl nuclear accident remain a topic of interest. We investigated germline de novo mutations (DNMs) in children born to parents employed as cleanup workers or exposed to occupational and environmental ionizing radiation after the accident. Whole-genome sequencing of 130 children (born 1987-2002) and their parents did not reveal an increase in the rates, distributions, or types of DNMs relative to the results of previous studies.

Estimation of radiation gonadal doses for the American-Ukrainian trio study of parental irradiation in Chornobyl cleanup workers and evacuees and germline mutations in their offspring.

Radiation doses of parents exposed from the Chornobyl accident as cleanup workers or evacuees were estimated in the National Cancer Institute-National Research Center for Radiation Medicine trio (i.e. father, mother, offspring) study aimed at investigating the radiation effects on germlinemutations in children as well as other outcomes.

INCIDENCE OF MALIGNANT NEOPLASMS AMONG RESIDENTS OF SMALL RADIONUCLIDE-CONTAMINATED CHORNOBYL DISTRICTS IN A POST-ACCIDENT PERIOD.

Objective: To assess the level of risks of development of malignant neoplasms among the residents of smallChornobyl districts («rayons») in connection with low-dose radiation exposure and its dynamic changes.

Materials And Methods: The study population included residents of Borodianka, Ivankiv and Poliske districts ofKyiv region («oblast») and Luhyny, Narodychi and Ovruch districts of Zhytomyr region, 175,100 inhabitants in2017. The study period was 1980-2017.

Field Study of the Possible Effect of Parental Irradiation on the Germline of Children Born to Cleanup Workers and Evacuees of the Chornobyl Nuclear Accident.

Although transgenerational effects of exposure to ionizing radiation have long been a concern, human research to date has been confined to studies of disease phenotypes in groups exposed to high doses and high dose rates, such as the Japanese atomic bomb survivors. Transgenerational effects of parental irradiation can be addressed using powerful new genomic technologies. In collaboration with the Ukrainian National Research Center for Radiation Medicine, the US National Cancer Institute, in 2014-2018, initiated a genomic alterations study among children born in selected regions of Ukraine to cleanup workers and/or evacuees exposed to low-dose-rate radiation after the 1986 Chornobyl (Chernobyl) nuclear accident.

EPIDEMIOLOGY OF BREAST CANCER IN UKRAINE WITH CONSIDERATION OF THE FACTORS OF THE CHORNOBYL ACCIDENT.

Objective: Assessment of the possible impact of the Chornobyl accident on the incidence of breast cancer in the female population of Ukraine as a whole and in some affected groups.

Object Of The Study: The female population of Ukraine as a whole and in separate groups of victims - women par- ticipating in the clean-up works in 1986-1987, evacuaees from the exclusion zone and inhabitants of the territo- ries most contaminated with radionuclides.

Methods: Statistical, mathematical, cartographic.

Estimation of Radiation Doses for a Case-control Study of Thyroid Cancer Among Ukrainian Chernobyl Cleanup Workers.

Thyroid doses were estimated for 607 subjects of a case-control study of thyroid cancer nested in the cohort of 150,813 male Ukrainian cleanup workers who were exposed to radiation as a result of the 1986 Chernobyl nuclear power plant accident. Individual thyroid doses due to external irradiation, inhalation of I and short-lived radioiodine and radiotellurium isotopes (I, I, I, Te, and Te) during the cleanup mission, and intake of I during residence in contaminated settlements were calculated for all study subjects, along with associated uncertainty distributions. The average thyroid dose due to all exposure pathways combined was estimated to be 199 mGy (median: 47 mGy; range: 0.

Cancers after Chornobyl: From Epidemiology to Molecular Quantification.

An overview and new data are presented from cancer studies of the most exposed groups of the population after the Chornobyl accident, performed at the National Research Center for Radiation Medicine (NRCRM). Incidence rates of solid cancers were analyzed for the 1990-2016 period in cleanup workers, evacuees, and the general population from the contaminated areas. In male cleanup workers, the significant increase in rates was demonstrated for cancers in total, leukemia, lymphoma, and thyroid cancer, as well as breast cancer rates were increased in females.

RADIATION RISKS OF THYROID CANCER IN CHORNOBYL CLEAN-UP WORKERS USING THE ALTERNATIVE ESTIMATES OF DOSES OF EXTERNAL EXPOSURE.

Objective: The objective of this study was to estimate the thyroid cancer radiation risks - excess absolute risk(EAR), excess relative risk (ERR) and attributable fraction of risk (AR) in the cohort of 150,813 Ukrainian male clean-up workers during the 1986-2012 period (more than 25 years after the Chornobyl accident).

Materials And Methods: The cohort under study of 150,813 Ukrainian men who participated emergency and clean-up work in 1986-1990 was formed based on the data of the Ukrainian State Register of persons affected due toChornobyl accident (SRU). The identification of thyroid cancer cases (216) was carried out by linking the SRU data-base with the National Cancer Registry of Ukraine (NCRU) data.

Epidemiology of Late Health Effects in Ukrainian Chornobyl Cleanup Workers.

This article summarizes the results of 30 y of follow-up of cancer and noncancer effects in Ukrainian cleanup workers after the Chornobyl accident. The number of power plant employees and first responders with acute radiation syndrome under follow-up by the National Research Center for Radiation Medicine decreased from 179 in 1986-1991 to 105 in 2011-2015. Cancers and leukemia (19) and cardiovascular diseases (21) were the main causes of deaths among acute radiation syndrome survivors (54) during the postaccident period.

Genomic characterization of chronic lymphocytic leukemia (CLL) in radiation-exposed Chornobyl cleanup workers.

Background: Chronic lymphocytic leukemia (CLL) was the predominant leukemia in a recent study of Chornobyl cleanup workers from Ukraine exposed to radiation (UR-CLL). Radiation risks of CLL significantly increased with increasing bone marrow radiation doses. Current analysis aimed to clarify whether the increased risks were due to radiation or to genetic mutations in the Ukrainian population.

Buccal mucosa micronuclei counts in relation to exposure to low dose-rate radiation from the Chornobyl nuclear accident and other medical and occupational radiation exposures.

Background: Ionizing radiation is a well-known carcinogen. Chromosome aberrations, and in particular micronuclei represent an early biological predictor of cancer risk. There are well-documented associations of micronuclei with ionizing radiation dose in some radiation-exposed groups, although not all.

Incidence of multiple myeloma among cleanup workers of the Chornobyl accident and their survival.

Unlabelled: The study presents the updated data on the multiple myeloma (MM) incidence in Ukrainian cleanup workers after the Chornobyl accident and their survival. The epidemiological analysis is based on the extended follow-up period to identify new MM cases for higher statistical power and to collect additional data on the disease course and outcome for the survival analysis. The objective of the study was to analyze the MM incidence and survival in Chornobyl cleanup workers in 1996-2013 in comparison with the national MM statistical data.

Chronic Lymphocytic Leukemia in Chornobyl Cleanup Workers.

This paper describes the chronic lymphocytic leukemia (CLL) incidence in a cohort of 110,645 (enlarged later to 152,520) male Ukrainian cleanup workers of the Chornobyl (Chernobyl) accident who were exposed to a range of radiation doses over the 1986-1990 time period. The standardized incidence rates are presented for a 27-y period after the exposure. For 2007-2012 period, the authors have identified the incident CLL cases in an enlarged cohort of 152,520 persons by linkage of the cohort file with the Ukrainian National Cancer Registry (NCRU).

Clinical characteristics of chronic lymphocytic leukemia occurring in chornobyl cleanup workers.

The recently demonstrated radiation-induction of chronic lymphocytic leukemia (CLL) raises the question as to whether the amount of radiation exposure influences any of the clinical characteristics of the disease. We evaluated the relationship between bone marrow radiation doses and clinical characteristics and survival of 79 CLL cases diagnosed during 1986-2006 in a cohort of 110 645 male workers who participated in the cleanup work of the Chornobyl nuclear accident in Ukraine in 1986. All diagnoses were confirmed by an independent International Hematology Panel.

Experience of study of the incidence of malignant neoplasms population in small areas of Ukraine, which suffered contamination with radionuclides due to the Chornobyl accident.

Goal Of The Study: to evaluate the dynamics of implementation risks of malignant tumors in some small areas of Ukraine in the pre- and post-accident period.

Materials And Methods: The study population group - the population of the Malyn rayon, Zhytomyr region. The period of observation covered 1980-2014.

Dosimetry Support of the Ukrainian-American Case-control Study of Leukemia and Related Disorders Among Chornobyl Cleanup Workers.

This paper describes dose reconstruction for a joint Ukrainian-American case-control study of leukemia that was conducted in a cohort of 110,645 male Ukrainian cleanup workers of the Chornobyl (Chernobyl) accident who were exposed to various radiation doses over the 1986-1990 time period. Individual bone-marrow doses due to external irradiation along with respective uncertainty distributions were calculated for 1,000 study subjects using the RADRUE method, which employed personal cleanup history data collected in the course of an interview with the subject himself if he was alive or with two proxies if he was deceased. The central estimates of the bone-marrow dose distributions range from 3.

Non-radiation risk factors for leukemia: A case-control study among chornobyl cleanup workers in Ukraine.

Background: Occupational and environmental exposure to chemicals such as benzene has been linked to increased risk of leukemia. Cigarette smoking and alcohol consumption have also been found to affect leukemia risk. Previous analyses in a large cohort of Chornobyl clean-up workers in Ukraine found significant radiation-related increased risk for all leukemia types.

Quarter of century since the Chornobyl accident: сancer risks in affected groups of population.

Objective. The goal of this study was to define levels and dynamic trends of cancer incidence at whole and some separate sites in groups of Ukrainian population affected by the Chornobyl accident during a long period of observation. Materials and methods.

Multiple myeloma among Chornobyl accident clean-up workers - state and perspectives of analytical study.

Unlabelled: The objective of the study was to analyze the Multiple Myeloma (MM) incidence in clean-up workers preparing the information background for consequent analytical study with a dose-dependent risk estimates.

Materials And Methods: The Cohort Database was linked to the Ukrainian National Cancer Registry to identify the MM cases in a cohort of 152 520 male clean-up workers.

Results: The 64 MM cases were identified in the studied Cohort for the 1987-2012 period.

Age and gender patterns of thyroid cancer incidence in Ukraine depending on thyroid radiation doses from radioactive iodine exposure after the Chornobyl NPP accident.

Unlabelled: The objective of this study was to investigate the thyroid cancer incidence in a whole territory of Ukraine and to clear up its age and gender patterns depending on average regional (oblast) thyroid doses from radioactive iodine due to the Chornobyl accident. MATERIALS AND METHODS. On the basis of average accumulated thyroid doses from radioactive iodine the geographical regions of Ukraine with low and high average thyroid doses were identified for a comparative analysis performance.