Black Americans are about 40% more likely to die from the disease than most other groups of patients. A recent study also found that 26% of Black Americans are diagnosed with CRC that has already metastasized, meaning the cancer has spread to other places in the body.
“The impact of social determinants of health on CRC diagnosis and treatment is clear to me as a practicing [cancer doctor] and person of color,” said Jason Willis, MD, PhD, a clinical investigator in the departments of Gastrointestinal Medical Oncology and Genomic Medicine at the University of Texas MD Anderson Cancer Center, Houston. “At a systemic level, we know that inequalities in health care access disproportionately impact many racial and ethnic minority groups. This is especially important when it comes to accessing preventative care and routine screening for common cancers, like CRC.”
The problem often exists throughout entire neighborhoods or cities.
“It may reflect a lack of access to primary care, inadequate referrals for screening, cultural barriers, and/or community-level factors,” Dr. Willis said. “Evidence has also suggested that some of the differences in CRC risk observed among various racial/ethnic communities may also be driven by differences in the prevalence of its underlying risk factors, such as tobacco use and type 2 diabetes.”
Black patients can also face information roadblocks when it comes to early CRC evaluation, said Christina M. Annunziata, MD, PhD, senior vice president of extramural discovery science at the American Cancer Society.
Other barriers may include a fear of the invasiveness of a colonoscopy, a lack of understanding of the benefits of screening, and lack of understanding of how family history with the disease plays a role, Dr. Annunziata said. “These apply across the U.S. population and are amplified with Black patients.”
Then there are disparities in treatment, which may come from a lack of health care access, including insurance coverage, transportation challenges, and the time required for treatment such as surgery, radiation, and chemotherapy, she said. “In addition, Black patients diagnosed with advanced-stage cancers require more intensive, expensive, and time-consuming treatment regimens that can be unattainable due to social and economic barriers,” she said.
Are there biological reasons Black people are more at risk for colorectal cancer?
Most likely, no. When Black patients received high-quality colonoscopies, there was no difference in the number of precancerous CRC polyps, or CRC tumors, when compared to White patients tested with the same equipment, according to data from Memorial Sloan Kettering Cancer Center. This further shows the importance of Black patients receiving early and effective screening for the disease.
But genetics may be one reason why CRC in Black patients can be difficult to treat. Additional research from Memorial Sloan Kettering found that colon cancer patients of African ancestry may have tumors that don’t respond well to immunotherapy and targeted cancer therapy.
The researchers found that these patients’ tumors were less likely to have the molecular profiles needed for these treatments to work.
But more research is needed. For now, researchers have very few clues as to why, when, and how these molecular and biological differences of CRC exist among various racial/ethnic and ancestral backgrounds, he said.
Black patients are also more likely to be diagnosed under the age of 50 as well. Researchers don’t know why this is exactly yet, but they think that poor diet, unhealthy bacteria in the gut, and inflammation may contribute to the cause. (Healthy eating and more exercise may lower a person’s risk.)