Geographic Variability of Gastric Cancer Incidence in Kazakhstan

OBJECTIVE: The article studies the geographical features of the incidence of gastric cancer (GC) in Kazakhstan. METHODS: The retrospective study was done for the period 2009-2018. Descriptive and analytical methods of oncoepidemiology were used. Crude (CR), age-specific (ASIR), age-standardized (ASR), equalized incidence rates and approximation were calculated. The dynamics of indicators was investigated using component analysis according to methodological recommendations. The method of drawing up a cartogram based on the determination of the standard deviation (σ) from the mean (x) was applied. RESULTS: During the study period, 27,467 new cases of GC were registered. The incidence rate increased from 16.80 (2009) to 15.10 in 2018 and the overall decline was 1.70 per 100,000 population, including due to the age structure – ∑Δ(A)=+1.51, due to the risk of acquiring illness – ∑Δ(R)=−2.91 and their combined effect – ∑Δ(RA)=−0.31. The component analysis revealed that the increase in the number of patients with GC was mainly due to the growth of the population (Δ(P)=+651.8%), changes in its age structure (Δ(A)=+433.9%) and changes associated with the risk of acquiring illness (Δ(R)=−832.1%). The cartograms were allocated according to the following criteria: low – up to 14.8(0)/(0000), average – from 14.8 to 19.2(0)/(0000), high – above 19.2(0)/(0000). The results of the spatial assessment showed the highest levels of GC incidence in following regions: Akmola (22.2(0)/(0000)), North Kazakhstan (22.3(0)/(0000)), and Pavlodar (23.2(0)/(0000)). CONCLUSION: Thus, as a result of the epidemiological 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 GC was evaluated, while sex differences and geographical variability were established.