Which patients should be screened for colorectal cancer?

Colorectal Cancer Screening: Patient Selection

Average-risk adults should begin colorectal cancer screening at age 45 years and continue through age 75 years, with screening decisions for ages 76-85 based on prior screening history, health status, and life expectancy. 1

Average-Risk Population

Age to Begin Screening

• Start screening at age 45 years for all average-risk adults using either high-sensitivity stool-based tests or structural examinations. 1
• The American Cancer Society updated their recommendation from age 50 to 45 years to address rising colorectal cancer incidence in younger adults. 1
• Traditional guidelines recommended age 50 years, but more recent evidence supports earlier initiation. 2

Age to Stop Screening

• Continue regular screening through age 75 years if patients are in good health with life expectancy greater than 10 years. 1
• For ages 76-85 years: Screen only if no prior screening history exists, considering comorbidities and life expectancy. 1
• Discontinue screening after age 85 years or when life expectancy is less than 10 years. 2, 1
• Patients up-to-date with screening who have negative results (particularly colonoscopy) can stop at age 75 years. 2

Definition of Average Risk

Average-risk patients are defined as those who are:

• 50 years or older (or 45 years by newer guidelines) 2, 1
• No personal history of colorectal polyps, colorectal cancer, or inflammatory bowel disease 2
• No family history of colorectal cancer in a first-degree relative diagnosed before age 60, or two first-degree relatives diagnosed at any age 2
• No family history of adenomatous polyps in a first-degree relative diagnosed before age 60 2

High-Risk Populations Requiring Earlier/More Frequent Screening

African Americans

• Begin screening at age 45 years due to higher disease burden and incidence rates. 2, 1
• Some guidelines suggest age 40 years for African Americans. 2

Family History of Colorectal Cancer or Advanced Adenomas

First-degree relative with colorectal cancer or advanced adenoma diagnosed before age 60, OR two first-degree relatives at any age:

• Begin colonoscopy at age 40 years OR 10 years before the youngest affected relative's diagnosis, whichever is earlier. 2, 1
• Repeat colonoscopy every 5 years. 2, 3

Single first-degree relative diagnosed at age 60 or older:

• Begin average-risk screening options at age 40 years. 2, 3
• Can follow standard screening intervals with earlier initiation. 2

Inflammatory Bowel Disease

Ulcerative colitis or Crohn's disease with colonic involvement:

• Begin colonoscopy 8 years after onset of pancolitis or 12-15 years after onset of left-sided colitis. 2, 4
• Repeat colonoscopy every 1-2 years with biopsies for dysplasia surveillance. 2, 4

Hereditary Syndromes

Familial Adenomatous Polyposis (FAP):

• Begin annual flexible sigmoidoscopy at age 10-12 years. 2
• Provide genetic counseling and consider genetic testing. 2

Hereditary Nonpolyposis Colorectal Cancer (HNPCC/Lynch Syndrome):

• Begin colonoscopy at age 20-25 years OR 10 years before the youngest affected relative's diagnosis. 2
• Repeat colonoscopy every 1-2 years. 2, 4
• Genetic counseling and testing should be offered. 2, 4

Peutz-Jeghers Syndrome:

• Begin colonoscopy at age 8 years. 4
• If normal, repeat at age 18 years, then every 3 years. 4

Sessile Serrated Adenomatous Polyposis:

• Begin annual colonoscopy as soon as diagnosis is established. 4

Personal History of Adenomatous Polyps

Advanced adenomas (≥1 cm, villous features, or high-grade dysplasia):

• Repeat colonoscopy within 1-3 years after polypectomy. 2
• If no recurrence, extend interval to 3-5 years. 2

Large or multiple adenomatous polyps:

• Colonoscopy 3 years after initial polypectomy. 2
• Subsequent intervals depend on findings (5 years if normal or single small tubular adenoma). 2

Personal History of Colorectal Cancer

• Patients with resected colorectal cancer require surveillance colonoscopy with intervals determined by clinical judgment and tumor characteristics. 2

Symptomatic Patients Under Age 50

Adults under age 50 with colorectal bleeding symptoms (hematochezia, unexplained iron deficiency anemia, melena with negative upper endoscopy):

• Undergo colonoscopy or sufficient evaluation to determine bleeding cause regardless of screening age recommendations. 2
• This addresses the rising incidence of colorectal cancer in younger adults. 2, 3

Common Pitfalls to Avoid

• Do not delay screening in African Americans—they have higher incidence and should begin at age 45 years (or 40 years by some guidelines). 2, 1
• Do not use average-risk protocols for patients with family history—they require earlier and more frequent colonoscopy. 2
• Do not continue screening indefinitely—overuse of colonoscopy in elderly patients, particularly over age 80, is a documented problem. 2
• Do not ignore symptoms in younger patients—colorectal cancer incidence is rising in those under 50 years. 2, 3
• Ensure positive stool-based tests are followed by colonoscopy—failure to follow up negates screening benefits. 1