Abstract
Objective: To conduct a spatial assessment of breast cancer (BC) incidence in Kazakhstan over 2004-2023, quantify inter-regional differences in crude and age-standardized rates, and classify regions by incidence level.Methods. We performed a retrospective, ecological study at the level of administrative regions (regions, plus the cities of Almaty and Astana). Official data on first-ever BC cases among women (ICD-10: C50) and regional female population counts were analyzed. Mapping was used to visualize geographic variation and to classify regions into low, medium, and high incidence levels. Distributional normality was evaluated using Westergaard’s numbers and Pearson’s χ² goodness-of-fit test (α=0.05).Results. Between 2004 and 2023, 80,490 BC cases were registered; the mean age at diagnosis was 57.4±0.2 years. The mean crude incidence was 45,2±1,3 per 100,000 women, and the age-standardized rate (ASR) was 41.8±0,9 per 100,000. Marked geographic heterogeneity was observed: higher incidence levels clustered in northern, central, and highlyurbanized regions, while comparatively lower levels were seen in the south and parts of the west. By ASR, low-incidence regions included Zhambyl, South Kazakstan, Kyzylorda, Mangystau, Almaty (oblast), and Atyrau; high-incidence regions included Karaganda, Pavlodar, and the cities of Almaty and Astana. The distribution of regional indicators was statistically compatible with normality, supporting the use of parametric models.Conclusion. Breast cancer incidence in Kazakhstan exhibits pronounced inter-regional heterogeneity with a discernible north–south gradient. The choropleth maps and incidence-level classification provide an evidence base for region-tailored strategies: maintaining screening quality and coverage in high-incidence areas, and expanding access to diagnostic services in low-incidence areas.Keywords:breast cancer, geographic variability, incidence, Kazakhstan, spatial assessment.