Demographic and temporal trends in stroke-related mortality in women with breast cancer in the United States: A retrospective analysis from 1999 to 2020.

e22537 Background: Breast cancer is the second most common cancer worldwide and the most commonly diagnosed cancer in women. In the United States (US), the estimated mortality rate of breast cancer (BC) in the year 2019 was 27 per 100,000 women. Studies have shown an increased incidence of stroke in patients with BC, in addition to significant geographical variations and racial disparities in BC mortality rates. We aim to assess the temporal trends in stroke-related deaths in women with breast cancer in the US from 1999 to 2020, stratified by race/ethnicity, age groups, census regions, and urbanization. Methods: We used the Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research (CDC WONDER) database for data of all death certificate records with stroke as the underlying and breast cancer as a contributing cause of death. Crude (CRs) and age-adjusted mortality rates (AAMRs) with 95% confidence intervals (CIs) were calculated per 100,000. The temporal trends were analyzed by determining the annual percentage change (APC) and the average APC using Joinpoint regression. Results: From 1999 to 2020, a total of 12,646 stroke-related deaths were recorded in women with BC in the US. The AAMR decreased significantly from 1999 to 2011 (APC: -5.66, 95% CI: -8.52 to -3.42) followed by a period of stability till 2018 (APC: -1.93; 95% CI: -6.30 to 1.01) and an abrupt increase from 2018 to 2020 (APC: 11.92; 95% CI: 0.76 to 18.27). The highest AAMR was exhibited by non-Hispanic (NH) Blacks or African Americans (0.30) and the lowest by Hispanics or Latinos (0.13). The AAMRs decreased sharply from 1999 to 2013 for NH Blacks or African Americans (APC: -4.95, 95% CI: -13.76 to -3.07) followed by a stable trajectory till 2020 (APC: 3.29, 95% CI: -1.92 to 22.18). NH Whites also demonstrated a similar significant decrease in AAMR from 1999 to 2014 with (APC: -5.13, 95% CI: -6.76 to -4.38) and a period of stability thereafter till 2020 (APC: 2.17, 95% CI: -1.53 to 13.61). Older individuals showed much higher CRs, with about thrice the rates in the 85+ years age group (7.82) than the 75 to 84 years age group (2.25). Regional variation in AAMRs was evident (West: 0.32, Midwest: 0.31, South: 0.25, Northeast: 0.24). Greater AAMRs were exhibited by rural areas (0.32) than urban ones (0.27). Conclusions: While the stroke-related deaths in women with breast cancer initially declined in the US, the mortality rates have started to rise in recent years. The highest burden was observed in NH Blacks or African Americans, older individuals, residents of the West, and those living in rural areas. Targeted efforts must be initiated to reduce the disparities in healthcare and curb the burden of stroke in women with BC.