What are the current recommendations for colon cancer screening, prevention, and treatment?

Colorectal Cancer Screening Recommendations

Average-risk adults should begin colorectal cancer screening at age 45 years with either colonoscopy every 10 years or annual fecal immunochemical testing (FIT) as first-line options, continuing through age 75 years. 1, 2

Screening Initiation by Risk Category

Average-Risk Adults

• Begin screening at age 45 years for all average-risk individuals, though this is a qualified recommendation with stronger evidence supporting screening from age 50 years onward 1, 2
• The American Cancer Society lowered the starting age from 50 to 45 years in 2018 based on rising colorectal cancer incidence in younger adults 1
• Average-risk is defined as: no personal history of polyps, colorectal cancer, or inflammatory bowel disease; no family history of colorectal cancer in first-degree relatives diagnosed before age 60; and no hereditary cancer syndromes 1

High-Risk Adults

• Begin screening at age 40 years OR 10 years younger than the age of diagnosis of the youngest affected relative, whichever comes first, for individuals with:
  • One first-degree relative with colorectal cancer or advanced adenoma diagnosed before age 60 1, 2
  • Two or more first-degree relatives with colorectal cancer at any age 1
• Use colonoscopy every 5 years as the only recommended screening method for high-risk individuals 1

Special Populations

• African Americans should begin screening at age 45 years due to higher incidence rates 1
• Individuals with Lynch Syndrome should begin colonoscopy 10 years before the age at diagnosis of the youngest affected relative 2
• Inflammatory bowel disease patients require colonoscopy every 1-2 years starting 8 years after onset of pancolitis or 12-15 years after onset of left-sided colitis 1

First-Tier Screening Options

Colonoscopy every 10 years and annual FIT are the cornerstone first-tier screening tests that should be offered first to all average-risk patients 1, 3

Colonoscopy

• Perform every 10 years for average-risk adults 1
• Perform every 5 years for high-risk adults 1
• Unique advantage: detects AND removes precancerous polyps, providing both screening and prevention 1
• Physicians performing screening colonoscopy must measure quality metrics, particularly adenoma detection rate 1

Fecal Immunochemical Test (FIT)

• Perform annually for average-risk adults 1
• Requires commitment to annual at-home testing with strict adherence to manufacturer's instructions 1
• Must be followed by timely colonoscopy if positive 1
• More sensitive than older guaiac-based tests 1

Second-Tier Screening Options

For patients who decline both colonoscopy and FIT, offer these alternatives in sequential fashion 1:

• CT colonography every 5 years 1
• Multitarget stool DNA (FIT-DNA) every 3 years 1
• Flexible sigmoidoscopy every 5-10 years, optionally combined with annual FIT 1

These tests are acceptable but have disadvantages compared to first-tier options, including incomplete colon visualization (sigmoidoscopy), higher cost (stool DNA), or radiation exposure (CT colonography) 1

When to Stop Screening

Age 75 Years

• Continue screening through age 75 years for adults in good health with life expectancy greater than 10 years 1, 2
• This is a qualified recommendation for those who have been regularly screened 1

Ages 76-85 Years

• Consider stopping screening for individuals who are up-to-date with prior negative screening tests, particularly if they had high-quality colonoscopy 2
• For those without prior screening, decisions should be individualized based on overall health status and life expectancy, but screening may still be appropriate 1, 2

Age 85 Years and Older

• Discontinue screening as harms outweigh benefits 1, 2

Critical Implementation Points

Shared Decision-Making

• Present colonoscopy and FIT as first-line options when discussing screening with patients 1
• The "best screening test is the one that gets done" - patient preference matters for adherence 1
• Discuss benefits, harms, costs, availability, and frequency of each test 1, 4

Quality Monitoring

• Colonoscopy programs must track adenoma detection rates as a quality metric 1
• FIT programs must monitor quality including completion rates and timely follow-up of positive results 1

Follow-Up Requirements

• All positive non-colonoscopy screening tests require timely diagnostic colonoscopy 1
• Single-panel guaiac fecal occult blood test performed in the office during digital rectal examination is NOT recommended due to very low sensitivity 1

Common Pitfalls to Avoid

• Do not delay evaluation of symptomatic individuals regardless of age, especially those with bleeding symptoms - these patients need diagnostic evaluation, not screening 2
• Do not use older, low-sensitivity guaiac tests (like Hemoccult II) - use high-sensitivity versions or FIT instead 1
• Do not continue screening beyond age 85 when evidence shows harms outweigh benefits 2
• Do not offer barium enema as a screening option - more sensitive tests are available 1
• Do not use serum Septin9 assay for screening due to insufficient evidence 1

Treatment Considerations

For patients diagnosed with colorectal cancer requiring adjuvant chemotherapy, oxaliplatin 85 mg/m² combined with fluorouracil and leucovorin every 2 weeks is the standard regimen, continuing for up to 12 cycles or until unacceptable toxicity in the adjuvant setting 5. Dose modifications are required for peripheral neuropathy (reduce to 75 mg/m² for persistent Grade 2, discontinue for Grade 3-4) and myelosuppression 5.