Abstract B014: Income level associated with death from cardiovascular disease after breast cancer in the Women’s Health Initiative
Authors: Jones Veronica , Wang Yongzhe , Vasbinder Alexi , Simon Noah , Reding Kerryn 
Published: December 2023

Introduction: Breast cancer (BC) treatment has known cardiotoxic effects. While increased risk of death from cardiovascular disease (CVD) after BC has been demonstrated in select racial/ethnic minorities, less is known about the association of social determinants of health (SDH) variables on death from CVD after BC treatment. Methods: Using data from the Women’s Health Initiative, we examined factors associated with increased risk of death from CVD after BC diagnosis among 8,728 women (n=7,433 non-Hispanic White (NHW); n=706 non-Hispanic, Black (NHB); n=288 Hispanic, n=271 non-Hispanic Asian; n=30 missing racial information) . Cox proportional hazard model was used to analyze the relationship between survival outcomes (death due to BC, death due to CVD, and adjudicated CVD after BC) and race/ethnicity and income. Income level was stratified into less than $35,000, $35,000-$74,999, and greater than or equal to $75,000. Results: Income level less than $35,000 was associated with a significantly increased risk of death due to CVD after BC (HR=1.57; 95% CI: 1.34, 1.84) compared to income between $35,000 and $74,999. Income greater than $75,000 was associated with a significantly less risk of death due to CVD after BC (HR=0.56; 95% CI: 0.45, 0.71).  A higher cumulative incidence of death from BC and death from CVD was associated with the lowest income bracket. Furthermore, death from CVD surpassed death from BC around 13 years after BC diagnosis for income levels less than $35,000 and at 20 years after BC diagnosis for those with income levels between $35,000 and $74.999. However, for the highest income bracket of greater than $75,000, death from CVD never surpassed cumulative incidence of death from BC. Hispanic women were less likely to have death due to CVD after BC compared to NHW women (HR=0.10; 95% CI:0.49,0.77). No significant difference in death from CVD was seen between NHW and NHB women. Among NHW women, those with income less than $35,000 had higher likelihood of death from CVD (HR=1.58; 95% CI: 1.34, 1.84), compared to those with income between $35,000 and $74,999. NHW women with greater than $75,000 had a less likely chance of dying compared to those with income between $35,000 and $74,999 (HR=0.61; 95% CI 0.49, 0.77). A difference in death due to CVD across income levels was not observed among NHB women. However, among Hispanic women with less than $35,000 annual income, a 10- fold increased risk of death from CVD was observed compared to Hispanic women with annual income $35,000-$74,999 (HR=10.41; 95% CI 1.43, 75.57). Conclusion: In the WHI, income level was strongly associated with increased risk of death from CVD after BC, especially among NHW and Hispanic women, but not among NHB women. Clinical trials investigating therapies with potential cardiotoxic effects must include patients with diverse income levels to prevent potentially exacerbating BC disparities.

Citation Format: Veronica Jones, Yongzhe Wang, Alexi Vasbinder, Noah Simon, Kerryn Reding. Income level associated with death from cardiovascular disease after breast cancer in the Women’s Health Initiative [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B014.