In individuals younger than age 50 undergoing a colonoscopy, greater odds for having colorectal cancer were observed among those who presented with rectal bleeding, according to findings from a study presented at the American College of Surgeons (ACS) Clinical Congress 2025 and published in the Journal of the American College of Surgeons.
“Many of the early-onset colorectal cancers that I see have no family history,” said senior author Sandra Kavalukas, MD, FACS, Colorectal Surgeon at the University of Louisville School of Medicine in Louisville, Kentucky. “This research lends support to the question of who does or doesn’t warrant a colonoscopy: if you have a person below the screening age with rectal bleeding, you should seriously consider a colonoscopy.”
Rationale and Study Methods
Researchers sought to understand the multifactorial etiology of early-onset colorectal cancer in individuals under 50 years, a growing issue, to help determine which individuals should be recommended for early screenings.
Currently, U.S. Preventive Services Task Force guidelines recommend colonoscopies among adults beginning at the age of 45 for most individuals without a family history of colorectal cancer.
Jin et al conducted a retrospective cohort analysis of early-onset colorectal cancer cases and non-cases from individuals undergoing colonoscopy for any reason between 2021 and 2023. They also looked at pathology reports, demographics, symptoms, and family history.
Key Study Findings
Of the 443 eligible individuals who underwent a colonoscopy, 195 had early-onset colorectal cancer (44%). Eighty-eight percent of these patients received a colonoscopy because of symptoms compared with 55% of non-cases (P < .001).
Multivariate models showed that cases of colorectal cancer were associated with benign colon indications (adjusted odds ratio [aOR] = 7.64; 95% confidence interval [CI] = 4.12–14.16), rectal bleeding (aOR = 8.56; 95% CI = 4.51–16.24), a family history of colorectal cancer (aOR = 2.05; 95% CI = 1.22–3.43), and a former smoking history (aOR = 1.95; 95% CI = 1.11–3.43).
Thirty-nine percent of all patients who had early-onset colorectal cancer presented with rectal bleeding vs 23% of non-cases.
“If they’re 35 and they come in with rectal pain, they probably don’t need a colonoscopy,” Dr. Kavalukas explained. “But if they come in with a bleeding complaint, they are 8.5 times more likely to have a colorectal cancer.”
Only 13% of colorectal cancer cases were microsatellite-deficient, and 70% did not have a family history of colorectal cancer.
Disclosure: For full disclosures of the study authors, visit journals.lww.com.
