ACS: Rectal Bleeding Tied to More Than Eightfold Higher Risk for Early-Onset Colorectal Cancer

THURSDAY, Oct. 9, 2025 (HealthDay News) — Adults younger than 50 years of age undergoing colonoscopy have a dramatically higher risk for colorectal cancer (CRC) when the procedure is done for rectal bleeding, according to a study presented at the annual meeting of the American College of Surgeons, held from Oct. 4 to 7 in Chicago.

Allie Jin, from the University of Louisville School of Medicine in Kentucky, and colleagues conducted a retrospective cohort study to examine factors associated with early-onset CRC (EOCRC). Pathology reports, demographics, symptoms, and family history were compared for EOCRC cases and noncases who underwent colonoscopy at a tertiary care center (2021 to 2023) for any reason.

Among 443 patients younger than 50 years (44 percent EOCRC cases), the researchers found that most EOCRC cases (88 percent) underwent colonoscopy due to symptoms compared with 55 percent of noncases. CRC cases were significantly more likely to have a benign colon indication (adjusted odds ratio [aOR], 7.64), bleeding (aOR, 8.56), and a family history of CRC (aOR, 2.05), and were more likely to be former smokers (aOR, 1.95). EOCRC cases were more likely to present with bleeding (39 percent versus 23 percent of noncases). Only 13 percent of EOCRC cases were microsatellite-deficient.

“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,” senior author Sandra Kavalukas, M.D., also from the University of Louisville, said in a statement.

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