U.S. Colorectal Cancer Rate Rose in 2023 for the First Time in 20 Years

U.S. colorectal cancer incidence fell for more than two decades. In 2023 it rose. The age-adjusted rate was 38.3 new cases per 100,000 people, up from 36.7 in 2022, according to an analysis in NEJM Evidence led by Caitlin Murphy, a professor of public health sciences at the University of Chicago. It drew on National Cancer Institute registry data from 2000 to 2023.

What the registry numbers show

Murphy called the 2023 figure the first rise in the overall rate in more than 20 years. The jump is small. The 2023 rate is still about 30 percent below the 2000 rate, and it comes from a single year of data. The authors call for continued monitoring because registry data are updated annually.

That 45-to-49 jump has a partial explanation. National guidelines lowered the recommended starting age for screening from 50 to 45, and more screening finds more cancers. Murphy framed it as the system working: screening, she said, is catching cancer earlier.

Why the older groups are harder to explain

Screening does not account for the rest. Rates are also climbing at ages 50 through 69, and the 70-to-74 group has stopped declining. The University of Chicago release says people in the 65-to-74 range are about 80 percent up to date on screening, so a rise there cuts against the idea that missed colonoscopies are the driver.

The authors point to a birth cohort effect, meaning people born in the 1960s and later carry higher risk as they age. They also tested the pandemic explanation. Dropping 2020 and 2021 from the analysis did not remove the increase, and screening had returned to prepandemic levels by January 2021. Murphy's own summary of the puzzle: whatever is raising risk in younger adults now appears to be raising it in older adults too.

Where the evidence conflicts

The American Cancer Society reported something different in March. Its Colorectal Cancer Statistics, 2026 report, led by Rebecca Siegel, found incidence rising 3 percent a year in ages 20 to 49 and 0.4 percent a year in ages 50 to 64. For ages 65 and older it found incidence falling by more than 2 percent a year, using data through 2022.

The two reports do not match for the oldest group. One plausible difference is the data window, since the NEJM Evidence analysis runs through 2023. The sources available for this story do not say whether that explains it, and the NEJM Evidence paper itself returned an access error, so this article relies on the university's release, which Medical Xpress also carries, rather than the full text. The release does not report the study's sample size. It has not been replicated.

What is being tested next

Nothing here identifies a cause. Murphy and Xin Hu at Emory University plan to measure thousands of chemical exposures in small blood samples. Sonia Kupfer, who directs the GI Cancer Risk and Prevention Clinic at UChicago Medicine, will then test the most promising chemicals in lab-grown colon tissue called organoids. Those are plans, not results.

The stakes are practical. Colorectal cancer is the second leading cause of U.S. cancer deaths overall and the leading cause among adults under 50. The American Cancer Society projects 158,850 new cases and 55,230 deaths for 2026, and it puts screening prevalence in the 45-to-49 group at only 37 percent. Murphy also warned that more diagnoses in an aging population could strain treatment and survivorship care.

Current U.S. guidance, as the release summarizes it, covers screening for average-risk adults from 45 through 75, with individualized decisions outside that range. The bottom line: the long decline has paused for at least one year, the reason is unknown, and the oldest age groups are where the explanation is thinnest.