New study shows Black cancer survivors face increased mortality from heart disease

A new study from researchers at the American Cancer Society (ACS) found that Black cancer survivors in the United States experience a higher risk of dying from cardiovascular disease (CVD) compared with white cancer survivors.

The research showed Black cancer survivors carry from 30% up to a three-fold higher mortality risk from CVD, depending on the type of cancer that was diagnosed. Differences in neighborhood socioeconomic status and health insurance between Black and white cancer survivors explained the disparities in cardiovascular death rates between populations, according to the study authors. The paper was published in the International Journal of Epidemiology.

"These findings underscore the importance of neighborhood-level interventions and equitable access to care to mitigate the racial inequities in CVD mortality among cancer survivors," said Dr. Hyuna Sung, lead author of the study and senior principal scientist of cancer surveillance research at the American Cancer Society. "We need to identify and support neighborhoods where targeted efforts for health promotion and cancer survivorship can have the greatest impact."

Generally, all cancer survivors have an increased risk for CVD because of the cardiotoxicities of cancer treatments and possible shared risk factors that impact cancer and cardiovascular disease. For this study, researchers examined population-based data from 17 different surveillance, epidemiology, and end result registries, including more than 900,000 cancer survivors of working age (20–64 years) in the U.S.

Researchers analyzed data to see the impact of census tract-level neighborhood socioeconomic factors such as education level, percent working class, percent unemployment, median household income, median house value, median rent, and poverty level while also looking at clinical factors for differences in mortality.

The results showed among survivors surveyed, 10,701 CVD deaths occurred during 43 months of median follow-up. Black survivors were more likely than white survivors to die from CVD with the racial differences in relative terms across 18 cancer types, ranging from 1.3-fold for lung cancer to 4.0-fold for brain cancer.

Results based on mediation analyses suggest that substantial proportions (25% to 64%) of the excess cardiovascular death among Black survivors of 14 cancer types are accounted for by racial differences in neighborhood socioeconomic status. For example, approximately 64% of the excess cardiovascular death among Black versus white lung cancer survivors was mediated by socioeconomic disparities in neighborhoods where Black and white cancer survivors reside.

Racial disparities in health insurance status also appeared to be important contributing factors, explaining 12% to 31% of the excess cardiovascular death among Black versus White survivors.

While the study identified a link between neighborhood-level socioeconomic status and CVD mortality after a cancer diagnosis, it was not designed to determine which specific attributes captured with the neighborhood measure are most influential.

"Where you live shouldn't determine if you live, but unfortunately that's the reality for far too many people," said Lisa A. Lacasse, president of the American Cancer Society Cancer Action Network, ACS' advocacy affiliate.

"Successfully fighting cancer depends on access to timely, high-quality, affordable health care coverage and treatment. This study underscores the importance of ensuring that everyone has equitable access to high-quality affordable health care, which includes expanding Medicaid in the 10 remaining states that have not done so. This would cover more than two million uninsured people who fall into Medicaid coverage gap—nearly 30% of whom are Black."

"The findings have implications for clinical guidelines for evaluating cardiovascular risk and prognosis among individuals with a history of cancer," added Sung.

"Although it is well established that incorporating social determinants of health into screening and interventions for cardiovascular care significantly improves patient outcomes, current guidelines concerning cardiovascular health and risk management among cancer survivors mostly omit social determinants of health-informed approaches. These guidelines can be updated to incorporate social determinants of health-informed practices and to help providers identify and address their patient's social needs."

Other ACS authors participating in this study include: Noorie Hyun, Rachel E. Ohman, Eric H. Yang, Rebecca L. Siegel, and Dr. Ahmedin Jemal.