Doctors were significantly less likely to order colorectal cancer screening with the at-home test Cologuard (Exact Sciences) for Black patients and were more likely to order the test for Asian patients, new evidence reveals.
Investigators retrospectively studied 557,156 patients in the Mayo Clinic health system from 2012 to 2022. They found that Cologuard was ordered for 8.7% of Black patients, compared to 11.9% of White patients and 13.1% of Asian patients.
Both minority groups were less likely than White patients to undergo a follow-up colonoscopy within 1 year of Cologuard testing. Cologuard tests the stool for blood and DNA markers associated with colorectal cancer.
Although the researchers did not examine the reasons driving the disparities, lead investigator Ahmed Ouni, MD, told this news organization that “it could be patient preferences ... or there could be some bias as providers ourselves in how we present the data to patients.”
Dr. Ouni presented the findings on May 22 at the annual Digestive Disease Week® (DDW), held in person in San Diego and virtually.
Breakdown by physician specialty
“We looked at the specialty of physicians ordering these because we wanted to see where the disparity was coming from, if there was a disparity,” said Dr. Ouni, a gastroenterologist at Mayo Clinic, Jacksonville, Florida.
Just over half (51%) of the patients received care from family medicine physicians, 27% received care from internists, and 22% were seen by gastroenterologists.
Family physicians ordered Cologuard testing for 8.7% of Black patients, compared with 16.1% of White patients, a significant difference (P < .001). Internists ordered the test for 10.5% of Black patients and 11.1% of White patients (P < .001). Gastroenterologists ordered Cologuard screening for 2.4% of Black patients and 3.2% of White patients (P = .009).
Gastroenterologists were 47% more likely to order Cologuard for Asian patients, and internists were 16% more likely to order it for this population than for White patients. However, the findings were not statistically significant for the overall cohort of Asian patients when the researchers adjusted for age and sex (P = 0.52).
Black patients were 25% less likely to have a follow-up colonoscopy within 1 year of undergoing a Cologuard test (odds ratio, 0.75; 95% confidence interval, 0.60-0.94), and Asian patients were 35% less likely (OR, 0.65; 95% CI, 0.52-0.82).
Ongoing and future research
Of the total study population, only 2.9% self-identified as Black; according to the 2020 U.S. Census, 12.4% of the population of the United States are Black persons.
When asked about the relatively low proportion of Black persons in the study, Dr. Ouni replied that the investigators are partnering with a Black physician group in the Jacksonville, Fla., area to expand the study to a more diverse population.
Additional plans include assessing how many positive Cologuard test results led to follow-up colonoscopies.
The investigators are also working with family physicians at the Mayo Clinic to examine how physicians explain colorectal cancer screening options to patients and are studying patient preferences regarding screening options, which include Cologuard, fecal immunochemical test (FIT)/fecal occult blood testing, CT colonography, and colonoscopy.
“We’re analyzing the data by ZIP code to see if this could be related to finances,” Dr. Ouni added. “So, if you’re Black or White and more financially impoverished, how does that affect how you view Cologuard and colorectal cancer screening?”
