Trends in Stage-Specific Kidney Cancer Incidence in Kazakhstan, 2005-2019

The aim is to analyze the incidence of kidney cancer over a 15-year period, considering factors such as stage, age, sex, and morphological verification in the regional context in Kazakhstan.

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.

Among the meticulously documented 15,277 cases, a conspicuous male predominance was noted, comprising 53.7% of cases compared to 46.3% in females, with peak incidences observed within the 50-69 age cohorts. The average age at diagnosis exhibited a progressive rise over the study period, with discernible variations observed in age-specific incidence rates, particularly pronounced within the 60-84 age brackets. Noteworthy temporal trends indicated a consistent uptick in crude incidence rates, with distinct regional disparities manifesting higher rates in northern regions relative to their southern and western counterparts. Stratification by cancer stage unveiled a significant surge in stages I-II cases alongside a concomitant decrement in stage III incidences, complemented by reductions in stage IV occurrences and instances of unspecified disease stages. Morphological verification rates displayed regional variations, with an overarching ascending trajectory across most regions, albeit exceptions noted, notably in the Kyzylorda region.

Our study identified a rise in kidney cancer incidence in Kazakhstan, likely reflecting global trends driven by increased risk factor exposure and incidental imaging findings. Regional disparities and varied stage distributions highlight the complexity of kidney cancer epidemiology. Despite advancements in early detection, delayed diagnosis persists, necessitating improved surveillance and diagnostic practices.