Thyroid Cancer Incidence in the Republic of Belarus

The accident at the Chernobyl nuclear power plant was the largest radiation-ecological catastrophe, which was accompanied by a massive release of the radioactive isotope of iodine, which was assimilated by a large part of Belorussian people. The aim of this work was to investigate the incidence of thyroid cancer in Belarus and assess the risk of developing this disease in various groups of affected cohorts. The data from the State Register of persons affected by the Chernobyl accident (from 1987 to 2015) and the data of the Belarusian Cancer Registry (from 1978 to 2015) were used in the study. The analysis was conducted using crude rates (CR), age-specific rates (AsR) and age-standardized rates (ASR) and standardized incidence ratio (SIR). It was shown the intensive increase in the incidence rates of thyroid cancer in the Belorussian population after the Chernobyl accident, which finished after 2001 (CR1986=1,5±0,24, CR2001=10,3±0,63, CR2015=12,5±0,71). Thyroid cancer growth was most significant in most contaminated Gomel, Mogilev and Brest areas. It was shown that the maximum increase in incidence was observed in persons aged 0-4 years at the time of the accident. In the affected population, significantly high risk of thyroid cancer was noted in all groups. The risk was highest in the evacuees in 1995-1999 (SIR=13,0 (9,21-17,70)) and was significantly higher than in the liquidators (SIR=4,4 (3,63-5,25)) and in the cohort of living in contaminated areas (SIR=2,4 (1,88-2,98)). The risk was higher in men than in women, for those who were children at the time of the accident and who were in the most contaminated areas. The dose-response relationship was shown for the evacuees (rS=0,9, p=0,037) and for persons living in contaminated areas (rS=1,0, p<0,001). For the group of liquidators, the dose-effect relationship was not noted (rS=-0,48, p=0,329).

авария на ЧАЭС, рак щитовидной железы, радиационный фактор, заболеваемость, риск, пострадавшее население, Chernobyl accident, thyroid cancer, radiation, incidence rates, risk, affected population

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