Colorectal cancer rates are rising sharply among people age 50 and younger, alarming oncologists, public health experts and health systems. Researchers say the causes are likely multifaceted and still under investigation.
Here are 10 key trends:
1. Gastrointestinal cancers are the fastest-growing cancer type in adults under 50.
Gastrointestinal cancers — including colorectal, stomach and pancreatic — are rising more rapidly than any other cancer type in people younger than 50. Colorectal cancer is the most common, with nearly 21,000 U.S. cases in 2022 alone, according to a July 17 study published in JAMA.
2. U.S. CRC cases in people under 50 have risen 2% annually since 2011.
According to data from the American Cancer Society, CRC diagnoses in people under 50 have increased 2% per year over the last decade.
3. Colorectal cancer rates are rising sharply in people under 25.
While routine screening starts at age 45, diagnoses among those ages 10-24 have surged dramatically over the past two decades. Cases in children ages 10-14 increased 500% and rates rose 185% in people ages 20-24, NBC News reported in May 2024.
4. Screening rates in 45- to 49-year-olds remain low, despite updated guidelines.
Even though the U.S. Preventive Services Task Force lowered the recommended screening age to 45 in 2021, uptake is still lagging. Hesitancy around cost and bowel prep remains a major barrier, with 83% of Medicare claims for bowel prep involving cost-sharing, according to a study published in Gastroenterology.
5. Younger patients often face late diagnoses and worse outcomes.
Younger CRC patients often receive diagnoses at later stages and, even when diagnosed early, may experience poorer outcomes than older patients, despite more aggressive treatment. The cancer may be biologically more aggressive in younger populations, according to the JAMA study.
6. Younger colorectal cancer patients show distinct tumor bacteria and more advanced tumors.
A 2024 study published in ScienceDirect comparing tissue from patients under 50 with older patients found unique tumor-related bacteria and a higher likelihood of left-sided, rectal and advanced-stage tumors in younger patients.
7. Lifestyle and early-life exposures may play a role.
Obesity, sedentary lifestyles, diet and adolescent exposure to sugar-sweetened beverages are potential risk factors, according to the JAMA study. The study also points to changes in the gut microbiome, antibiotic use and environmental exposures as likely contributors.
8. Genetic testing is recommended for all CRC patients under 50.
The JAMA study also found that between 15% and 30% of early-onset gastrointestinal cancer cases involve a hereditary genetic mutation, prompting researchers to recommend universal genetic testing for patients under 50.
9. New data supports the effectiveness of screening younger adults.
A study published Oct. 22 in Annals of Internal Medicine found that fecal immunochemical testing was just as effective in adults ages 45-49 as it was in those age 50. Researchers analyzed over 267,000 FITs and found similar completion rates, follow-up colonoscopy rates and colorectal cancer detection across both age groups.
10. Increased awareness drives more young adults to seek colonoscopies.
Gastroenterologists noted a surge in patients aged 45 to 49 requesting colonoscopies, spurred by symptom awareness, family history and influential public figures like Ryan Reynolds promoting screening.
