TORONTO, Ontario — Chemotherapy remains one of the most viable treatment options for many cancer patients, despite the litany of unpleasant side-effects associated with this approach to killing cancer cells. Besides the more common side-effects such as hair loss or nausea, chemotherapy can also increase the risk of treatment-related heart damage, such as heart failure and cerebrovascular disease, in many patients. Now, new research out of Canada reports Black individuals in particular, or patients of African ancestry, are 71 percent more at risk of cardiotoxicity following cancer treatment in comparison to Caucasian patients.
Cardiotoxicity refers to any heart damage resulting from cancer treatments or drugs, such as chemotherapy agents and radiation. This condition can eventually lead to numerous heart problems including heart failure, cardiomyopathy, and an irregular heart rhythm. Notably, certain cancer treatments come with a higher risk of inducing cardiotoxicity, including anthracyclines, which doctors typically use to treat leukemias, lymphomas, and various cancers (breast, stomach, uterus, ovary, and lung).
“Unfortunately, we were not surprised [by the findings]. Research shows that Black patients have poorer outcomes for almost every disease,” says lead author Wondewossen Gebeyehu, BSc, a medical student at the University of Toronto, in a media release. “In this case, one could have expected that the differences would be minimal since it is the chemotherapy that is injuring the heart, and we would expect the same chemotherapy to be given to Black and non-Black patients with a given cancer. However, this systematic review indicates that the inequities in health outcomes extends to the odds of cardiotoxicity after cancer treatment.”
Study authors conducted a systematic search of several databases (Medline, Embase, Pubmed, and more) in pursuit of all studies reporting on cardiovascular toxicity in cancer patients of different racial/ethnic backgrounds receiving chemotherapy. Ultimately, after screening 7,057 studies, the team chose a total of 24 studies representing 683,749 participants for the final review. Black race or African ancestry was found to have a connection with a 71-percent increased chance of chemotherapy-associated cardiotoxicity. African ancestry also displayed a link to increased odds of a congestive heart failure diagnosis.
“These results may reflect the direct effects of racism, particularly structural racism, which leads to worse determinants of health for Black patients. It is well-documented that most health care settings are not perceived as safe by Black patients, which may increase their vulnerability to disease and decrease opportunities for preventative care,” Gebeyehu explains. “Furthermore, decreased representation of Black patients in clinical trials may lead to treatments being developed that are not as effective or which may be riskier for Black patients. Importantly, these results should prompt further inquiry into the many possible contributors to disparities observed in Black patients.”
Study authors believe these findings quantify the increased odds of chemotherapy-associated cardiotoxicity among Black cancer patients. This study also highlighted the urgent need for more research focusing on determining the underlying factors contributing to these disparities.
“The most important message for patients is that they should not avoid chemotherapy, as the most important thing is making sure they get the best cancer treatment possible, and studies already show Black patients may get less optimal cancer treatments,” Gebeyehu concludes. “For clinicians, it is important to be aware of these higher odds of cardiotoxicity faced by Black patients. Understanding these disparities will hopefully lead to clinicians having more conversations around reducing cardiovascular risk associated with chemotherapy and targeted efforts to cater to groups at higher risk.”
Study authors presented the research at the American College of Cardiology’s Advancing the Cardiovascular Care of the Oncology Patient 2023 conference.