Trends of Colorectal Cancer Incidence in Kazakhstan

BACKGROUND AND OBJECTIVE: Colorectal cancer (CRC) remains one of the most widespread human malignancies. The aim of this study was to study trends of the incidence of CRC in Kazakhstan. MATERIALS AND METHOD: This retrospective study was done using descriptive and analytical methods of oncoepidemiology. RESULTS: During the study period from 2009 to 2018, 28,950 new cases of CRC were recorded, 13,779 (47.6%) cases were allocated to men and 15,171 (52.4%) to women. It was found that the incidence rate of CRC increased from 14.79 (2009) to 17.72 in 2018 and the overall growth was 2.93 cases per 100,000. This increase was due to the age structure – ∑Δ(A)=+1.42, the risk of acquiring illness – ∑Δ(R)=+1.31, and their combined effect – ∑Δ(RA)=+0.20. The component analysis results revealed that the increase in the number of patients with CRC was mainly due to the growth of the population (ΔP=+37.7%), changes in age structure (Δ(A)=+26.6%), and changes associated with the risk of acquiring illness (Δ(R)=+24.6%). The number of patients (both sexes) was increasing in many regions largely due to the influence of the age structure of the population. In addition, it was found that growth in the number of patients in most regions, both men and women, was associated primarily with the risk of acquiring illness. CONCLUSION: The findings of the current study showed increasing trends in the incidence of CRC in all regions of the country. These changes were mainly influenced by demographic factors (population size and age structure), risk of acquiring the disease, and their combined effect.