Analysis of the Incidence of Solid Malignant Neoplasms in the Urals Cohort of Exposed Population Offspring

Purpose: The study of regularities in the incidence of solid cancer in the Urals Cohort of the Exposed Population Offspring over a 65-year follow-up period. Material and methods: The study was conducted by cohort method. The cohort under study is the Urals Cohort of the Exposed Population Offspring. It includes offspring of the population exposed in the period from 1950 to 1960 in the Southern Urals (on the Techa River and at the East Urals radioactive trace). The catchment area includes 5 districts of the Chelyabinsk region, as well as the city of Chelyabinsk and the city of Ozyorsk. The follow-up period was 65 years, from 01.01.1956 to 31.12.2020, the number of the analytical cohort for 2024 is 24952 people, the number of person-years under follow-up is 850698. Calculation of cases, incidence rates, person-years and statistical processing of data were performed by standard methods using the DATAB program module of the Epicure statistical package. Results: During the 65-year period, 569 cases of solid cancers were registered in the catchment area. In women the most frequent cases were neoplasms of female reproductive organs, breast, thyroid gland, whole intestine and upper digestive tract organs; in men - respiratory organs, upper digestive tract and whole intestine. A significant increase in the incidence rates was found in women in age groups older than 20 years and in men in groups older than 30 years. Statistically significant sex-depended differences were observed only in the age groups between 30 and 50 years. No significant differences in the incidence rates among offspring of different ethnic groups were found. An assessment of incidence rates by calendar periods was carried out: in women, a significant increase in incidence rates began in 1990, in men in 2005 and significant differences by sex were observed only in the period from 2005 to 2020. Conclusion: The study revealed patterns in the incidence of solid malignant neoplasms within the offspring cohort by sex, age and depending on the calendar period. These patterns will be taken into account in future studies when assessing the dependence of the incidence of solid malignant neoplasms in offspring on parental gonadal dose.