PurposeDespite a nationwide breast cancer screening program in Korea, spatial disparities in stage at diagnosis persist.This study aimed to examine disparities in breast cancer incidence by stage and their association with area-level risk factors. Materials and MethodsWe conducted a population-based ecological study using data from the Korea National Cancer Incidence Database (2005Database ( -2018)).Among 230,214 women diagnosed with breast cancer, 215,803 with known stage were included.Stage-specific incidence across 250 municipalities was estimated for three periods (2005-2008, 2009-2013, and 2014-2018).For 2014-2018, associations with the area deprivation index (ADI), obesity rate, alcohol consumption rate, cancer screening rate, and mammography unit availability were assessed using Bayesian hierarchical models. ResultsOf 215,803 patients, 59.0% had localized-stage, 35.5% regional-stage, and 5.5% distant-stage.Localized-stage incidence was higher in affluent areas, whereas distant-stage incidence was higher in deprived areas.In multivariable models, lower ADI (β = -0.058;95% credible interval CrI: -0.098, -0.019), lower obesity rate (β=-0.066;95% CrI: -0.091, -0.041), and higher mammography availability (β=0.014;95% CrI: 0.001, 0.027) were significantly associated with higher localized-stage incidence.Conversely, higher ADI (β=0.103;95% CrI: 0.017, 0.188) and higher alcohol consumption (β=0.227;95% CrI: 0.115, 0.338) were significantly associated with increased distant-stage incidence. ConclusionSpatial disparities in stage-specific breast cancer incidence in Korea were associated with area-
Park et al. (Mon,) studied this question.