Colorectal cancer is striking younger Americans at rates doctors haven’t seen in decades, even as the disease keeps fading among older adults.
Quick Take
- Federal data show 155,662 new colorectal cancer cases reported in the United States in 2023.
- Cases are rising 1.2% to 3.8% a year in adults under 65, while falling among people 65 and older.
- Colorectal cancer is now the top cancer killer of men under 50 and the second-leading killer of women that age.
- Doctors still don’t know exactly why younger adults are getting sick more often.
The Numbers Behind A Troubling Shift
The Centers for Disease Control and Prevention counted 155,662 new colorectal cancer cases across the country in 2023. That number alone doesn’t prove rates are climbing nationwide. But when researchers break the data down by age, a clear pattern shows up. Younger adults are getting diagnosed more often, while older adults are getting diagnosed less often than they used to.
The National Cancer Institute tracked this split closely between 2012 and 2021. Incidence climbed 3.8% every year among people ages 15 to 39. It rose another 1.2% annually among those 40 to 64. Meanwhile, cases dropped 2.2% a year among people 65 to 74, and fell even faster, 2.7% a year, among those 75 and older.
Younger Adults Now Carry A Heavier Burden
This shift has changed who colorectal cancer kills. Twenty years ago, it ranked fourth among cancer deaths in adults under 50. Today it’s the leading cause of cancer death in young men and the second-leading cause in young women. That’s a dramatic jump for a disease most people still associate with retirement age.
The American Cancer Society’s broader numbers back this up. Overall colorectal cancer rates fell about 1% a year from 2011 to 2019. But among people younger than 55, rates have climbed 1% to 2% every year since the mid-1990s. Rates in the 55 to 64 group have simply leveled off, neither rising nor falling much.
Decades Of Decline Among Older Americans Continue
Older adults tell a very different story. Federal cancer registry data covering 2019 through 2023 put the overall age-adjusted rate at roughly 36.2 cases per 100,000 people, with rates still falling by an average of 0.5% a year from 2014 to 2023. Decades of widespread colonoscopy screening among people over 50 helped catch and remove precancerous polyps before they turned into tumors, driving down cases in that population.
That long success story is exactly why the youth trend stands out so sharply. The disease isn’t spreading evenly across all ages. It’s retreating where screening has worked for decades and advancing where it hasn’t been standard practice until recently. That contrast is reshaping how doctors think about who needs to worry.
Why This Is Happening Remains An Open Question
Here’s the honest gap in the research: nobody has pinned down why younger adults are getting diagnosed more often. The National Cancer Institute states plainly that the reasons behind the increase in younger people are not known, though changing patterns in diet, obesity, alcohol use, and other lifestyle factors may play some role.
Scientists studying this pattern internationally have noticed it tracks closely with when people were born rather than just their current age. Research following U.S. cancer registries from 1974 to 2013 found that risk has been climbing in each successive generation, with people born more recently facing higher odds at the same age than their parents did. Similar birth-year patterns have shown up in France, Taiwan, and other countries, suggesting something shared across generations, not a single American cause, is driving the trend.
Screening Rules Have Already Started To Change
Health officials responded to this data by lowering the recommended age to start routine colorectal cancer screening from 50 to 45. That change means more younger adults are now getting checked, which could itself affect how many cases get caught and counted. Separating true increases in disease from increases in detection is one of the trickiest parts of reading these numbers correctly.
For now, the clearest fact is this: colorectal cancer has stopped being an old person’s disease in the public imagination. Families, doctors, and screening guidelines are all adjusting to a reality where a diagnosis in your 30s or 40s is no longer rare enough to ignore. Figuring out exactly why will take years of further research into diet, genetics, and the body’s own biology.
Sources:
mindbodygreen.com, cdc.gov, pressroom.cancer.org, cancer.org
