Liver Cancer Incidence in Kazakhstan: Fifteen-Year Retrospective Study.

OBJECTIVE

The aim is to study the trends of liver 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

Between 2005 and 2019, 13,510 cases of LC were documented, comprising 59.3% males and 40.7% females. Most diagnoses were seen in age groups 55-59 years (13.3%) to 75-79 years (11.7%). LC patients' average age increased from 63.6 to 64.5 years. Incidence rates per 100,000 peaked at ages 65-69 years (35.1±1.0) and 70-74 years (43.3±1.0). LC incidence notably rose in the 70-74 years age group (APC=+0.89), contrasting with declining trends in younger age groups. Regional incidence variations revealed diverse patterns, mostly demonstrating unimodal increases, and some regions displaying bimodal growth. The age-standardized incidence rate was 5.7±0.1 per 100,000, declining from 2005 to 2012 (APC: -3.93), then rising until 2019 (APC: +1.13). Gender-specific standardized rates showed varied trends. Analyses of standardized indicators indicated declining trends in most regions but increased values in specific areas. Thematic maps classified incidence rates based on standardized indicators: low (up to 5.22), average (5.22 to 7.11), high (above 7.11 per 100,000 for the entire population).

CONCLUSION

The study on liver cancer in Kazakhstan reveals marked gender and age differences. The standardized incidence rate among men was twofold greater than that among women. A distinct rise in cases was noted among individuals aged 70-74 years. Regional variations in incidence were evident. These findings emphasize the necessity for focused research to comprehend the causes behind these differences, enabling customized interventions for Kazakhstan's population.