Breast cancer incidence in Indonesia: a sex-disaggregated analysis using WHO health equity assessment toolkit data.

Introduction: Breast cancer is the most common cancer among women globally, with notable disparities in incidence between sexes, particularly in low and middle-income countries. Understanding these disparities is essential for tackling health inequities, particularly in Indonesia, where access to screening and treatment is spatially inconsistent. This study examined the trends and disparities in breast cancer incidence in Indonesia from 2000 to 2019, utilizing sex-disaggregated data from the World Health Organization's Health Equity Assessment Toolkit (HEAT).

Methods: Age-standardized breast cancer incidence rates (per 100,000 population) from the WHO HEAT were measured. The HEAT platform sources data from the Institute for Health Metrics and Evaluation (IHME), which compiles data from national cancer registries and health surveys. Four inequality indicators were calculated to assess the absolute and relative differences in breast cancer incidence between males and females: Difference, Ratio, Population Attributable Fraction, and Population Attributable Risk. All estimates were presented with Confidence Intervals (CI).

Results: Between 2000 and 2019, the age-standardized incidence of breast cancer in Indonesia declined from 19.1 to 16.0 per 100,000 population. Nonetheless, considerable sex disparities remained. In 2019, the incidence rate for females was 37.4 (CI: 29.0-48.6), whereas for males it was 0.4 (CI: 0.2-0.5). The absolute difference in incidence between sexes rose from 31.0 in 2000 to 37.1 in 2019. The relative disparity persisted, with females being over 100 times more predisposed to breast cancer than males (ratio = 104.4 in 2019). The population attributable fraction and population attributable risk values continuously demonstrated that almost all breast cancer cases were associated with females. PAF values fluctuated from - 98.6% in 2000 to -98.1% in 2019.

Conclusions: The incidence of breast cancer in Indonesia is declining; yet, sex disparities remain, with females bearing a disproportionately greater burden. These findings underscore the need for targeted public health strategies, including expanded access to breast cancer screening programs, public awareness campaigns to promote early detection, and improved availability of diagnostic and treatment services tailored to women. Future research ought to identify and mitigate female-specific risk factors, such as hormonal and reproductive factors, and lifestyle impacts, to enhance prevention measures, are critical for reducing these disparities and improving health outcomes.