Impact of Screening on Breast Cancer Incidence in Kazakhstan: Results of Component Analysis.

OBJECTIVE The study is to conduct a component analysis of the dynamics of the incidence of BC (BC) in Kazakhstan, taking into account regions. METHODS Primary data were for registered patients with BC (ICD 10 - C50) in the whole country during the period of 2009-2018. Evaluation of changes in BC incidence in the population of Kazakhstan was performed using component analysis according to the methodological recommendations. RESULTS The study period, 40,199 new cases of BC were recorded. The incidence rate increased from 39.5 (2009) to 49.6 in 2018 and the overall growth was 2.8 per 100,000 population of female, including due to the age structure - ∑ΔA=+2.99, due to the risk of acquiring illness - ∑ΔR=+6.82 and their combined effect - ∑ΔRA=+0.31. The component analysis revealed that the increase in the number of patients with BC was mainly due to the growth of the population (ΔP=+31.1%), changes in its age structure (ΔA=+18.0%) and changes associated with the risk of acquiring illness (ΔR=+41.0%). The increase in the number of patients in the regions of the republic is associated with the influence of demographic factors and with risk factors for getting sick, including mammographic screening. CONCLUSION Thus, as a result of the component analysis, the role of the influence of demographic factors and the risk of acquiring illness on the formation of the number of patients and the incidence of BC was evaluated, while geographical variability was established. This research was the first epidemiological study of the dynamics of BC in the regional context by the method of component analysis in the population of Kazakhstan. The implementation of the results of this study is recommended in management of anticancer activities for BC.