Rising CRC in Younger Adults Signals Urgent Need for Awareness, Action: Rebecca L. Siegel, MPH

Overall colorectal cancer (CRC) incidence and mortality have declined in the US, but rates are rising among individuals younger than 65, according to findings from the “Colorectal Cancer Statistics, 2026” report published yesterday in CA: A Cancer Journal for Clinicians.¹

The report’s release at the start of National CRC Awareness Month, recognized each March, further underscores the need to educate the public about the disease and encourage screening.

The American Journal of Managed Care^® (AJMC^®) recently spoke with Rebecca L. Siegel, MPH, senior scientific director of surveillance research at the American Cancer Society and lead author of the report, to discuss these findings in greater detail. In part 1 of the interview, she outlined how trends have shifted since the 2023 update and the factors driving the rise in CRC incidence and mortality among younger adults.

Learn more about the report’s findings here.

This transcript has been lightly edited for clarity.

AJMC: To start, based on findings from the “Colorectal Cancer Statistics, 2026” report, how have trends shifted since the 2023 update?

Siegel: We have a few novel findings this year. One of the major new findings is that rectal cancer incidence rates are increasing in all age groups combined. This is on the heels of decades of decline in rectal cancer, so this was surprising and a new finding. The reason that this is happening is because of the increase in incidence rates in people aged under 65, really driven by tumors in the distal colon and rectum.

Now, even in older adults, although incidence rates are still declining for rectal cancer, they're not declining as swiftly as for other sub-sites. So, there is, even in that older group, a preponderance of rectal cancer.

Now, we're seeing an increase in the overall incidence of rectal cancer, as well as an increase in both incidence and mortality for CRC in people younger than 65. The increase in mortality in middle-aged people aged 50 to 64 is also a new finding.

AJMC: The report shows CRC incidence rising in younger adults while continuing to decline in older adults. What factors may be driving this generational divergence?

Siegel: The CRC declines in the older adults are because of the lifetime accumulation of exposures, like the decline in smoking and increased use of anti-inflammatory drugs like aspirin and ibuprofen, as well as increased screening that really began with colonoscopy in the 2000s and accelerated the declines. Additionally, for mortality rates, there's been the contribution of improvements in treatments.

All of these things are also acting on younger adults, but there is something that's happening among people born in the middle of the 20th century, so people who are born after the 1950s, that is, elevating the risk of CRC. It's called a birth-cohort effect, and it means that when you were born is really what determines your risk at every age. Every generation born after 1950 has a little bit higher risk than the generation born before. Some exposure or behavioral factors changed around the 1950s, which are increasing our risk of CRC, particularly our risk of distal colon and rectal cancer, which are what's driving it. That's why you're seeing this divergence in trends.

Before incidence rates began increasing in people under 50, they were decreasing, and likewise for people aged 50 to 64. The trend was decreasing across all age groups until this unknown exposure that started increasing risk, and that's where you see contemporary exposures. You first see the influence in younger adults, and that's why trends in younger adults are so important for assessing progress against cancer.

AJMC: CRC is now the leading cause of cancer-related death in adults under 50, with 3 in 4 cases in the 45 to 49 age group diagnosed at an advanced stage. What factors may be contributing to these trends?

Siegel: It's actually 2 different points: the fact that there are a lot of advanced-stage diagnoses is contributing to the increasing mortality in people under 50. That finding is from a paper that we published about a month ago in JAMA, showing that among the 5 leading causes of cancer death in people under 50, the only cancer type that's increasing is CRC²; it's now become the leading cause of cancer death in that age group.

The reason CRC in people younger than 50 is diagnosed at an advanced stage is that they have only recently become eligible for screening.¹ Now, people aged 45 to 49 are eligible. Screening should begin at age 45 for people who are at average risk. A lot of people should be screened before 45, so everyone should talk to their family about their family history, not just for CRC but for polyps or adenomas during a colonoscopy.

Even if you had a benign adenoma or polyp, it means your family is at higher risk for CRC and should start screening earlier. So, it's about understanding your family history, communicating that with your doctor, and then, for people who do not have any of that family history, starting to screen at 45 will help facilitate earlier diagnosis.

For people who are at average risk and who are younger than 45, just understanding the symptoms of CRC. There are red flag symptoms for people under 50. More than 40% of cancers diagnosed before 50 have symptoms like bleeding from the rectum or blood in the stool. Also, abdominal pain is a common symptom, as is anemia.

So, just being aware of these symptoms, and if you have these symptoms, follow up with your doctor. Part of increasing awareness is normalizing this conversation because young adults, especially, don't want to talk about these types of issues, such as blood in the stool. If they're having that, they might be embarrassed, so talking about it more, normalizing it, and reducing the stigma will also help get earlier diagnoses for people, especially those who are younger than the screening age.

References

1. Siegel RL, Wagle NS, Star J, Kratzer TB, Smith RA, Jemal A. Colorectal cancer statistics, 2026. CA Cancer J Clin. 2026;e70067. doi:10.3322/caac.70067
2. McCormick B. CRC becomes leading cause of cancer-related death in younger adults, highlighting prevention gaps. AJMC. January 26, 2026. Accessed March 5, 2026. https://www.ajmc.com/view/crc-becomes-leading-cause-of-cancer-related-death-in-younger-adults-highlighting-prevention-gaps