Research and discussion about the high cancer rates among Black Americans used to be dominated by genetics and the search for biological differences. Now attention has shifted to the social determinants of health.
There’s a cancer problem in the US, say many experts, and dazzling new treatments and brilliant scientific advances are not going to solve it.
The problem is cancer’s disproportionate effect on Black people in the United States, who have the highest death rate and shortest survival periods of any racial or ethnic group in the country. For many of the most common cancers (lung, breast, colon, prostate), the incidence rate among Black people is lower than the rate among white non-Hispanic people, yet the death rate among Black people is higher.
Most of these disparities are nothing new and have long been recognized. What has changed is the thinking (and research) into their causes. For many years, the tip of the cancer research spear was directed at genetic and biological explanations. Researchers and policymakers as well as oncologists are now focusing on societal factors and structural racism as the root cause of much of the disparity.
Anita Johnson, MD, FACS, chief of surgery and leader of the Women’s Cancer Center at Cancer Treatment Centers of America in Atlanta, says the challenges to accessing cancer care for minorities are multifactorial. Many can be traced to the social determinants of health (SDOH) that can put access to quality care, insurance, oncologists and clinical trial enrollment out of reach.
“Other challenges, such as access to healthy food options and environmental circumstances that expose individuals to carcinogens, also play a role,” continues Johnson, who also mentions the cultural barriers created by the lack of minorities in the health care professions. For example, recent research has shown that only 3% of oncologists in the US are African American.
Christina Chapman, MD, an assistant professor of radiation oncology at the University of Michigan Medical School, says the vast majority of the cancer-related issues that minority populations face are due to past or ongoing rules, norms, or laws that maintain societal inequity.
“Downstream problems like a lack of access to high-quality screening and treatment, or to clinical trials, are heavily rooted in societal inequity,” she says. “In the long term, social reform is needed to address inequity in income, wealth and health insurance access. In the short to medium term, health systems and cancer care providers need to recognize how inequity affects their patient populations and use existing resources that do help ensure that everyone has access to current therapies instead of solely focusing on new innovations that will not be accessible to many in the population.”
Social determinants … of cancer
Most cancers are caused by a complicated web of factors. The causal pathway gets even more complex with outcomes such as the five-year survival rate and death because of the many issues that influence access and the use of health care. All this complexity comes under the heading of SDOH, which loom large in the current understanding of the causes of cancer disparities.
“For example,” says Johnson, “regardless of education level, Black women in the US are known to have a higher rate of unemployment than White women. Being gainfully employed frequently provides individuals with benefits like health insurance and paid time off. These are important contributing factors to access screening, which can lead to earlier diagnoses of cancer and subsequently better outcomes, as well as the ability to seek and maintain cancer treatment.”
The incidence of breast cancer among White and Black women is similar, but Black women are 40% more likely to die from the disease. Higher rates of obesity and other health problems may be a factor (they may have upstream SDOH causes). Black women are also more likely to be diagnosed with aggressive types of the disease, such as triple-negative breast cancer and inflammatory breast cancer.
However, much of the mortality disparity can be ascribed to the cancer being diagnosed at a later, less treatable stage.
“Unfortunately, from experience — and now an increasing amount of empirical research — we know that the challenges are numerous and complex,” says David Arons, JD, CEO of the National Brain Tumor Society. “To name just a few challenges, (we have) cost, geography (distance to primary and specialty care because of a paucity of providers in rural underserved areas), cultural competence and unconscious bias, language barriers, mistrust and technological divides.”
For many types of cancer, SDOH heavily influence prevention, early detection and mitigation of disease, adds Arons. For example, he says, easy access to physical exercise including bikeable and walkable places near one’s home and access to nutritious food are associated with reduced chances of childhood obesity, which has been linked to the development of a number of cancers later in life.
Arons lists some other risk factors for cancer that are rooted in SDOH. Lack of education, combined with the marketing efforts of
tobacco companies, leads to higher rates of smoking, which is a major risk factor for lung and other cancers. Living in neighborhoods with high levels of air or water pollution puts people at risk.
Interestingly, Arons says the SDOH that shape the contours of risk and mortality for many cancers in the US do not appear to affect brain cancer rates. In fact, incidence rates are actually higher in highly educated White populations.
Niraj Mehta, MD, a radiation oncologist at GenesisCare, an Australian cancer care company that has expanded to the US, says that the biggest challenges for people living in poorer neighborhoods is access to care and removing the impediments to getting that care. These include lack of transportation and childcare and limited or no time off for their treatments.
“Such patients often present at a later stage of diagnosis and are often afflicted with comorbidities such as poor nutrition and obesity,” he says. “Meaningful education needs to go well beyond typical ‘awareness’ efforts. Many for-profit private equity organizations and hospitals likely have minimal impact in these communities. Bottom-line organizations typically do not explore these communities in depth to understand their needs on cancer and health in general.” In Mehta’s opinion, one of the first steps to redressing disadvantageous SDOH is funding outreach efforts by local physicians who have the cultural and sociodemographic sensitivities needed to work with patients in those poor neighborhoods.
Disparity in clinical trials
One area of disparity that has received a good deal of attention lately is enrollment in clinical trials. African Americans make up approximately 13% of the US population, yet less than 2% to 3% of patients enrolled in cancer clinical trials are Black. Breastcancer.org, a nonprofit website for information about breast cancer, reported that between 2% and 9% of the participants in the trials that led to FDA approvals of four new breast cancer treatments in 2020 were Black. The proportion of Latin Americans was similarly small.
“This is one specific example, but it reflects the trend that we see of inadequate representation of minorities in clinical trials,” says Johnson of Cancer Treatment Centers of America in Atlanta.
In May 2021, JCO Oncology Practice, an American Society of Clinical Oncology journal, published a special package of 16 articles and editorials about cancer disparities. A number of them focused on the low enrollment of Black patients with cancer in clinical trials. A study of clinical trials that led to FDA approval of an oral cancer drug showed that just 889 of 35,933 (2.47%) patients in the trials were Black.
Vonetta M. Williams, MD, Ph.D., a radiation oncologist at Memorial Sloan Kettering Cancer Center in New York, New York, says those numbers are very concerning because research has shown an association between clinical trial enrollment and improved outcomes. Williams says it is misguided to point to the attitudes of Black Americans as the reason for the low enrollment. “Many studies have cited mistrust (on the part) of Black Americans as a significant factor despite evidence showing that when offered enrollment, Black Americans consent to trial enrollment at similar rates to (those of) other groups,” she notes.
Ideas about how to increase enrollment of Black Americans in cancer clinical trials have proliferated. Williams says among the most promising are assessing trials’ inclusion and exclusion criteria to determine whether they are unnecessarily restrictive for certain populations. For example, many trials have cutoff points for the glomerular filtration rate, a measure of kidney function, that has led to the exclusion of Black Americans. Transportation and housing can also loom large as obstacles for some potential volunteers, Williams notes.
Lack of Medicaid coverage of the costs associated with participating in a trial has been another barrier for many Black patients. But at the beginning of 2022, the Clinical Treatment Act went into effect. It requires Medicaid to cover the routine costs of clinical trial participation for Medicaid enrollments with a life-threatening condition, including cancer.
Johnson says communication and connection between providers and minorities can help combat distrust of the health care system and improve health literacy.
Arons notes that the National Brain Tumor Society continues to argue for a policy that would include all National Cancer Institute-designated cancer centers as essential community providers in all marketplace health plans sold on the ACA exchanges. Lower-income individuals can sometimes end up in heath plans with slimmed-down provider networks that exclude the cancer centers, he says.
Keith Loria is a writer in the Washington, DC, area who covers healthcare.