Colorectal cancer disparities between Black and white adults were eliminated among Kaiser Permanente members in Northern California after it instituted a structured colorectal cancer screening program, new research shows.

“Our study found that organized screening works to improve colorectal cancer outcomes for all of our members,” says the study’s senior author Theodore R. Levin, MD, a research scientist at the Kaiser Permanente Division of Research and a gastroenterologist with The Permanente Medical Group. “I knew our program had helped to reduce disparities, but I was surprised by the magnitude and the rate of improvement. It exceeded my expectations.”

Screening programs create an opportunity to find colorectal cancers when they are small and easier to treat. Screening can also prevent cancers from developing through the removal of precancerous polyps.

Disparities between Black and white adults in colorectal cancer screening, incidence, and death rates have been documented for more than 40 years.

The new study, published in the New England Journal of Medicine, looked at colorectal cancer screening participation, incidence, and death rates for Black and white Kaiser Permanente members in Northern California age 50 to 75 from 2000 through 2019. The 19-year time period spanned 6 years before and 11 years after the colorectal cancer screening program was rolled out in 2006 through 2008.

In 2009, the colorectal cancer death rate was 54.2 for Black members and 32.6 for white members. By 2019, death rates had fallen by more than half among Black members—decreasing to 20.9—compared to 19.3 for white members, essentially eliminating the previous disparity. Colorectal cancer incidence also markedly decreased with similar rates seen between Black and white members.

“It is inspiring that organized screening outreach markedly and rapidly increases screening rates for everyone,” says the study’s co-lead author Douglas A. Corley, MD, PhD, MPH, a research scientist at the Kaiser Permanente Division of Research and a gastroenterologist with The Permanente Medical Group. “This is a powerful message that organization is crucial for knowing when and how to engage members in screening and follow-up.”

The findings highlight the need for health care organizations to address the social and structural barriers that contribute to ongoing health disparities.

“Many people have sought to show that health equity is not just a pipe dream,” says the study’s co-lead author Chyke A. Doubeni, MBBS, MPH, who directs the Mayo Clinic Center for Health Equity and Community Engagement Research. “This study shows how a thoughtful, intentional, coordinated, and sustained approach to delivering care in an equitable manner can eliminate health disparities.”

The colorectal cancer screening program identifies who needs screening and offers a choice of screening tests. Program managers and electronic systems identify all eligible members who are not up to date and automated alerts remind health care providers to offer screening at clinic visits. For members who are not up to date with screening, a fecal immunochemical test (FIT) is mailed annually. These tests are completed at home and returned by mail. Patients can request a colonoscopy, rather than use a FIT kit.

After starting organized screening outreach, the proportions of people up to date with screening rapidly increased, from about 40% among both Black and white Kaiser Permanente members in Northern California in 2009 to 80% among Black members and 83% among white members by 2019.

“Screening doesn’t stop with the delivery of the mailed fecal immunochemical test,” says Levin. “Ensuring people complete the screening and ensuring those who are positive complete a colonoscopy and, if needed, cancer treatment are all important parts of our program. We are also intentional to make sure our screening materials are culturally competent and address issues important to marginalized communities. This includes addressing concerns about trust in the health care system as well as making the connection between screening and being present for your family.”

The research team is already discussing ways to perfect and expand the program.

“We are always looking to improve, to understand why a small proportion of people choose not to be screened, to identify those at highest risk for more intensive screening, and to increase efforts for culturally appropriate care,” says Corley. “Our findings suggest similar organized approaches can play a major role nationally and internationally in decreasing disparities for colorectal cancer and potentially for other diseases.”

The study was funded by the National Cancer Institute.