BETHESDA, MD. (April 25, 2025) — A 20-year initiative that offered flexible options for colorectal cancer screening at a major integrated health system doubled colorectal cancer screening rates, cut cancer incidence by a third, halved deaths, and brought racial differences in outcomes to nearly zero, according to a study to be presented at Digestive Disease Week® (DDW) 2025 .
"By offering an effective screening approach equally to everyone, we were able to eliminate much of the disparity," said lead researcher Douglas Corley, MD, PhD, from the Kaiser Permanente Division of Research in Northern California. "Ten years ago, there were big gaps in cancer risk and death, especially among our Black patients. Now, those differences are nearly gone."
Kaiser Permanente Northern California researchers analyzed data from 1.1 million adults aged 50 to 75 across their 22 medical centers from 2000 to 2019. They evaluated outcomes of a systematic outreach, starting in 2007, that included reminding patients who were overdue for screening and sending them fecal immunochemical testing (FIT) kits for at-home tests.
Screening rates via colonoscopy, sigmoidoscopy, or FIT more than doubled — from 37.4% in 2000 to 79.8% in 2019 — across all racial and ethnic groups. Colorectal cancer diagnoses initially rose due to early detection but later declined, with incidence dropping systemwide by about 30%. Deaths from colorectal cancer decreased by about 50%, with the largest reductions seen in Black patients, whose deaths declined from 52.2 per 100,000 to 23.5 per 100,000.
Black patients in the United States have long had worse outcomes from colorectal cancer, likely from a mixture of risk factors and health care utilization. In this study, offering equal access to screening sharply reduced those disparities.
"We're not treating the root causes — we don't know if it's diet, exposures, or something else — but by making screening available to everyone, we were able to level the playing field," Dr. Corley said.
Dr. Corley added that flexibility was key to the dramatic increase in screening.
"If you offer people more than one option for screening — such as colonoscopy or FIT — they're more likely to get screened than if you offer either option by itself," he said. "To get above an 80% screening rate, you almost always have to offer people multiple options."
While Kaiser Permanente is a large, integrated system, Dr. Corley said the outreach model could work for other conditions that benefit from early interventions, such as high blood pressure and kidney disease, even in less-resourced settings. "We've seen safety-net systems and smaller clinics adopt similar mailing and follow-up strategies," he said. "It doesn't require high-tech tools, just organization and the will to reach people where they are."
