Colorectal Cancer Screening Guidelines

Introduction to Screening Recommendations

The American College of Physicians recommends against using serum screening tests for colorectal cancer due to lack of evidence for mortality benefit 3
Blood-based tests are not recommended for colorectal cancer screening in asymptomatic average-risk adults over 50, as they lack the evidence base that supports mortality reduction 1, 2

For average-risk adults aged 50-75 years, the American family physician recommends offering one of the following evidence-based options: annual fecal immunochemical test (FIT), colonoscopy every 10 years, or high-sensitivity guaiac-based fecal occult blood test (gFOBT) every 2 years, all of which have proven mortality reduction 1, 4
The U.S. Multi-Society Task Force specifically recommends against the Septin9 serum assay for screening due to insufficient evidence 3
Flexible sigmoidoscopy every 10 years plus FIT every 2 years is a combination approach with mortality benefit from randomized trials 1

Begin screening at age 50 for average-risk individuals with strong evidence supporting substantial net benefit, according to the American family physician 1, 2, 4
For ages 76-85 years, individualize the decision based on prior screening history, life expectancy exceeding 10 years, and overall health status, as recommended by the American family physician and Annals of Internal Medicine 1, 2, 6, 7
Stop screening at age 85+ years, as the harms outweigh benefits in this age group regardless of prior screening history, according to Annals of Internal Medicine and Ca-A Cancer Journal for Clinicians 2, 5, 3, 6

All positive stool-based tests require follow-up colonoscopy for diagnostic evaluation, which is non-negotiable, as recommended by the American family physician and Ca-A Cancer Journal for Clinicians 1, 5, 4
Assess life expectancy before initiating screening, and avoid screening if less than 10 years due to comorbidities, as screening is unlikely to provide benefit, according to Annals of Internal Medicine and Praxis Medical Insights 2, 7, 6, 4
The average time to prevent one CRC death is 10.3 years from screening initiation, as reported by Annals of Internal Medicine 2

Do not use blood tests, including Septin9 DNA assay, as they lack evidence for mortality benefit and are not guideline-endorsed, according to Annals of Internal Medicine 3
Do not continue screening past age 75 in patients with adequate prior screening history, as harms increasingly outweigh benefits with advancing age, as recommended by the American family physician, Annals of Internal Medicine, and Praxis Medical Insights 1, 2, 6, 4