Eliminating racial disparities in colorectal cancer testing may reduce the rate of colorectal cancer incidence and mortality among Black patients in the United States, according to a recent study published by Alagoz et al in the Journal of the National Cancer Institute.
Background
Although both the incidence and mortality of colorectal cancer have decreased over time, there are persistent racial disparities among Black patients—who may be 23% and 31% more likely to develop and die from the disease, respectively, compared with White patients. Previous research has shown that screening adherence may be the main driver of racial disparities in colorectal cancer incidence and mortality. A 2005 study using data from the National Health Interview Survey of patients older than 50 years showed that 52% of White patients were up-to-date on their colorectal cancer screenings vs 39% of Black patients. Over the past few years, that gap has narrowed and these rates have improved overall. In 2019, 69.5% of Black patients and 69.8% of White patients adhered to their screenings.
The benefits of colorectal cancer screening programs rely on patients completing a follow-up colonoscopy if physicians first discover an abnormal result in the patients older than 50 years who underwent initial noncolonoscopy tests as part of their normal treatment. The quality of a colonoscopy screening is also particularly important. Existing data demonstrate significantly lower follow-up colonoscopy rates among Black patients. Even if racial disparities in the receipt of colonoscopy screenings are small, disparities in outcomes can still be substantial. For instance, Black patients may be more likely than White patients to receive a low-quality colonoscopy.
Study Methods and Results
In the recent study, the investigators used previously established and validated mathematical cancer models as their analysis platform to assess other racial disparities related to colorectal cancer between Black and White patients. They simulated screening follow-ups and colonoscopy quality rates in Black patients to match those of White patients—with the goal of estimating how colorectal cancer outcomes could change with improvements in care and treatment.
The investigators discovered that eliminating these racial disparities in follow-up colonoscopy rates could reduce colorectal cancer incidence rates by 5.2% and reduce colorectal cancer mortality rates by 9.3%. Further, eliminating the disparities in colonoscopy quality could reduce both colorectal cancer incidence and mortality rates by 9.4%. Additionally, eliminating differences in both follow-up rates and colonoscopy quality could reduce colorectal cancer incidence rates by 14.6% and colorectal cancer mortality rates by 18.7%.
The investigators also found that eliminating differences in both follow-up rates and colonoscopy quality could reduce the colorectal cancer incidence gap between Black and White patients by 49%. Such changes would reduce the racial colorectal cancer mortality gap by 59%.
Conclusions
In this model, the elimination of the racial disparities in colonoscopy quality and follow-up colonoscopy rates would still not improve outcomes among Black patients compared with those of White patients. The investigators indicated that the remaining gap may be the result of racial differences in general health and how patients receive treatment.
“People have long known that racial disparities in cancer exist,” emphasized lead study author Oguzhan Alagoz, PhD, Professor of Industrial and Systems Engineering at the University of Wisconsin–Madison. “Usually, the focus has been on eliminating differences in adherence to screening, which reduces cancer deaths. However, our study shows that it's not enough to just get everyone screened; the quality of care during screening and follow-up must also be similar for Black and White [patients]. To truly close the racial gap in cancer deaths and achieve health equity, we need to find innovative solutions,” he concluded.
Disclosure: For full disclosures of the study authors, visit academic.oup.com.
