Loading ...

SAN DIEGO — A 20-year initiative by Kaiser Permanente Northern California that assessed colorectal cancer (CRC) screening status and offered flexible options for screening has made a huge difference in CRC incidence, deaths, and racial disparities, an analysis showed.

“The program promptly doubled the proportion of people up to date with screening,” reported lead investigator Douglas A. Corley, MD, PhD, a research scientist with Kaiser’s Division of Research, at a press briefing held on April 24, ahead of a presentation at the Digestive Disease Week (DDW) 2025.

Additionally, within about 10 years, cancer rates were cut by a third, deaths were halved for the second most common cause of cancer deaths in the United States, and the differences that had previously been seen by race or ethnicity were largely eliminated, he said.

“Ten years ago, there were big gaps in cancer risk and death, especially among our Black patients. Now, those differences are nearly gone,” Corley said.

Closing the Gap

A systematic CRC screening program was implemented across Kaiser Permanente Northern California. The program included proactive outreach to members who were overdue for screening and mailing them fecal immunochemical test (FIT) kits for at-home use.

Corley and colleagues tracked screening status and CRC incidence and mortality annually from 2000 to 2019 among about 1.1 million members aged 50-75 years across 22 medical centers of the integrated healthcare system. The cohort included American Indian or Alaska Native, Asian, Black, Hispanic, Native Hawaiian or Pacific Islander, and White members.

Screening rates via FIT, colonoscopy, or sigmoidoscopy more than doubled after starting the program, from about 37% in the early years to about 80% within a few years, and it stayed that high through 2019, Corley reported. 

“Importantly, these large increases occurred across the whole population with only small differences,” he said. 

For example, about 76% of Hispanic members, 77% of Black members, 82% of White members, and 83% of Asian members were up to date in the later years and through 2019.

“This shows that systematic, comparable outreach can provide a level playing field for completion of preventive care,” Corley said.

After an expected early uptick in CRC incidence due to early detection, incidence later declined and by 2019 had dropped approximately 30% across the groups.

Long-Standing Disparities Erased

CRC deaths also fell by about 50% across all groups, with the largest decline among Black members, Corley noted.

Racial and ethnic disparities in both CRC incidence and mortality have long existed, with Black patients in particular experiencing higher risks and worse outcomes, likely from a mixture of risk factors and healthcare utilization, Corley said.

Offering outreach and equal access to screening in the Kaiser program erased those long-standing disparities.

“It’s remarkable that some of these large differences in mortality by race and ethnicity that we saw two decades ago, and which are found throughout the United States, are now similar to small chance variation in the population,” Corley said.

Flexibility was key to getting more people screened, he noted. “It’s about reaching people at their homes and offering a choice to patients. It’s an astonishingly simple concept.”

It’s important to note that these findings stem from a large, integrated healthcare system, which may differ from other settings, although similar outreach strategies have succeeded in safety net clinics and smaller practices, Corley added.

By boosting screening rates to 80%, the health system reached the level that’s essentially been defined in the past as our goal of screening programs, said Loren Laine, MD, professor of medicine (digestive diseases) at Yale School of Medicine, New Haven, Connecticut, and chair of this year’s DDW. 

“It shows that if health systems institute programmatic screening for all their covered individuals, they could markedly increase screening, said Laine, who also served as moderator of the press briefing.

“Most importantly, of course, [screening] was associated with a reduction in colorectal cancer incidence and deaths,” he said.

The study had no commercial funding. Corley reported having no relevant conflicts of interest.

Laine’s disclosures included consulting and/or relationships with Medtronic, Phathom Pharmaceuticals, Biohaven, Celgene, Intercept, Merck, and Pfizer.