Epidemiology of Lung Cancer in Kazakhstan: Trends and Geographic Distribution.

OBJECTIVE: The aim is to study the trends of lung cancer (LC) incidence in the regional context in Kazakhstan. METHODS: The retrospective study was done using descriptive and analytical methods of oncoepidemiology. The extensive, crude and age-specific incidence rates are determined according to the generally accepted methodology used in sanitary statistics. The data were used to calculate the average percentage change (APС) using the Joinpoint regression analysis to determine the trend over the study period. RESULTS: Over the 10 years under study, 36,916 new cases of LC were registered in the country (80.5% - in men and 19.5% - in women). During the studied years the average age of patients was 64.2±0.1 years (95%CI=63.9-64.4). The highest incidence rates per 100,000 in the entire population were found in the age groups 65-69 years (147.6±2.7), 70-74 years (159.3±2.5), and 75-79 years (147.1±3.2). The incidence of LC tended to increase only at the age of 80-84 years (APC=+1.26) and the most pronounced average annual decline rates were observed in the age groups of 45-49 years (APC=-4.09), 50-54 years (APC=-4.20) and 85+ years (APC=-4.07). The average annual standardized incidence rate was 22.2 per 100,000, and in dynamics tended to decrease (APC=-2.04). There is a decrease in incidence in almost all regions, with the exception of the Mangystau region (APC=+1.65). During the compilation of cartograms, incidence rates were determined on the basis of standardized indicators: low - up to 20.6, average - from 20.6 to 25.6, high - above 25.6 per 100,000 for the entire population. CONCLUSION: The incidence of lung cancer in Kazakhstan is decreasing. The incidence among the male population is six times higher than among the female, while the rate of decline is more pronounced. The incidence tends to decrease in almost all regions. High rates were found in the northern and eastern regions.