Cardiovascular disease and breast cancer (BC) account for the most prevalent diseases and leading causes of death in the general population.1 The association between them is even more important in the context of their shared risk factors and the potential cardiotoxicity of many BC treatments. Hence, identifying external potentially modifiable factors affecting cardiovascular risk is key to improving outcomes for patients with BC. Racial disparities impact BC outcomes and may partially explain existing international differences: 5-year BC-specific survival is close to 90% in both the United States and Australia versus 40% in South Africa.2 However, socioeconomic deprivation also correlates with a greater prevalence of cardiovascular disease in patients diagnosed with BC.3
In this issue, Stabellini et al4 report the first study to demonstrate the association between social determinants of health (SDOH) and the risk of major adverse cardiovascular events for patients diagnosed with BC using race-agnostic and race-specific machine learning models. This study shows that SDOH may explain the racial differences noted in cardiovascular disease outcomes in women with BC, with neighborhood and built-environment variables representing the most important SDOH to predict a 2-year major adverse cardiovascular event. This underlines the importance of social constructs over ethnicity and represents a key direction for cancer policy work at the global level.
Nevertheless, this work has a few limits.
First, the study population may not be representative of the United States population. Importantly, non-Hispanic Black patients have a higher incidence of triple-negative BC and cardiomyopathy,4,5 two conditions that may correlate with genetic predisposition. Furthermore, triple-negative BC is more frequently treated with chemotherapy, which may lead to major adverse cardiovascular events in patients with a medium-high cardiovascular risk.6 Genome-sequencing studies identified variation in alleles associated with racial differences in incident heart failure. Specifically, Black individuals have an approximately 3-fold increased risk for developing dilated cardiomyopathy, and an approximately 2-fold increased risk of death after diagnosis not explained by socioeconomic status and cardiovascular risk factors.7 Thus, the worse cardiovascular outcomes in non-Hispanic Black patients may be the result of the interplay of biologic determinants and SDOH, further enhancing racial differences in heart failure outcomes. Therefore, the impact of specific genetic factors should be considered in the context of holistic and complex patient assessment and care.
Second, these findings may not be applicable to the global population of patients with cancer. The diversity of the ethnic composition and sociocultural differences across and within every country warrants similar research in different geographic areas. Access to healthcare is also a key consideration that may have influenced the findings of this study, due to the unique scenario of the US healthcare system.8
Importantly, social deprivation and disparities in access to healthcare may also affect the representation of patients in clinical trials. Therefore, greater efforts should be made to make research more inclusive, and SDOH should be taken into account to ensure that study results are applicable to broader patient groups.
The study by Stabellini et al4 highlights the importance of closer collaborations at 2 levels: first, in clinical care, between oncologists and cardiologists to safely and effectively treat cancer in the context of the individual cardiovascular risk; second, at the policy level, among the cancer workforce, the cardiology workforce, and policymakers to raise awareness around the importance of SDOH and adapt clinical care pathways and services and healthcare systems based on the diverse social and cultural background and needs of cancer populations.9
Finally, we hope that this work will lay the foundation for further research in more diverse populations and including additional SDOH defined by the WHO,10 such as urbanization policies and governance, climate change, and macroeconomics, that may also impact cardiovascular risk for patients with cancer. Such work would provide key insight to inform policy work to further improve outcomes for patients with BC.
References
- 1.↑
CDC. National Center for Health Statistics. Leading causes of death – females – all races and origins – United States, 2017. Accessed May 20, 2023. Available at: https://www.cdc.gov/women/lcod/2017/all-races-origins/index.html
- 2.↑
Allemani C, Matsuda T, Di Carlo V, et al. Global surveillance of trends in cancer survival 2000-14 (CONCORD-3): analysis of individual records for 37 513 025 patients diagnosed with one of 18 cancers from 322 population-based registries in 71 countries. Lancet 2018;391:1023–1075.
- 3.↑
Battisti NML, Welch CA, Sweeting M, et al. Prevalence of cardiovascular disease in patients with potentially curable malignancies: a National Registry Dataset Analysis. JACC CardioOncol 2022;4:238–253.
- 4.↑
Stabellini N, Dmukauskas M, Bittencourt MS, et al. Social determinants of health and racial disparities in cardiac events in breast cancer. J Natl Compr Canc Netw 2023;21:705–714.e17.
- 5.↑
Akinyemiju T, Moore JX, Ojesina AI, et al. Racial disparities in individual breast cancer outcomes by hormone-receptor subtype, area-level socio-economic status and healthcare resources. Breast Cancer Res Treat 2016;157:575–586.
- 6.↑
Lyon AR, López-Fernández T, Couch LS, et al. 2022 ESC Guidelines on cardio-oncology developed in collaboration with the European Hematology Association (EHA), the European Society for Therapeutic Radiology and Oncology (ESTRO) and the International Cardio-Oncology Society (IC-OS). Eur Heart J 2022;43:4229–4361.
- 7.↑
Nayak A, Hicks AJ, Morris AA. Understanding the complexity of heart failure risk and treatment in Black patients. Circ Heart Fail. Published online August 13, 2020. doi:10.1161/CIRCHEARTFAILURE.120.007264
- 9.↑
Van Poppel H, Battisti NML, Lawler M, et al. European Cancer Organisation's Inequalities Network: putting cancer inequalities on the European policy map. JCO Glob Oncol. Published online October 8, 2022. doi:10.1200/GO.22.00233
- 10.↑
World Health Organization. Social determinants of health. Accessed May 20, 2023. Available at: https://www.who.int/health-topics/social-determinants-of-health#tab=tab_2
MATILDE CORIANÒ, MD
Matilde Corianò, MD, is a final year Medical Oncology Resident at the University of Parma, Italy. She is also a Clinical Research Fellow at The Royal Marsden Hospital, London, UK.
MATTEO ARMILLOTTA, MD
Matteo Armillotta, MD, is a final year Cardiology Resident at the University of Bologna, Italy. He is also a Visiting Fellow at the Centre for Advanced Cardiovascular Imaging, St Bartholomew’s Hospital, London, UK.
NICOLÒ MATTEO LUCA BATTISTI, MD
Nicolò Matteo Luca Battisti, MD, MD(Res), is a Consultant Medical Oncologist in the Breast Unit of The Royal Marsden Hospital, London, UK. His focuses of clinical and research interest are breast oncology, geriatric oncology and inequalities in cancer care. He is President of the International Society of Geriatric Oncology (SIOG), member of the Clinical Implementation Core of the Cancer and Aging Research Group (CARG), member of the Oncology Section of the Royal Society of Medicine, and Co-Chair of the Inequalities Focused Topic Network of the European Cancer Organisation.