From the Guidelines
For individuals at average risk for colorectal cancer, screening colonoscopy is recommended to begin at age 45. This recommendation is based on the most recent guidelines from reputable organizations, including the American Cancer Society, the American College of Gastroenterology, and the US Preventive Services Task Force 1. The decision to start screening at age 45 reflects the increasing incidence of colorectal cancer among younger adults in recent decades.
Key Considerations
- The American College of Gastroenterology suggests screening in average-risk persons aged 45 to 49 years (conditional recommendation) and recommends screening average-risk persons aged 50 to 75 years (strong recommendation) 1.
- The US Preventive Services Task Force recommends screening adults between ages 50 and 75 years (Grade A) and beginning screening adults between ages 45 and 49 years (Grade B) 1.
- Colonoscopy is considered the gold standard for screening as it allows for direct visualization of the entire colon and rectum, and importantly, permits removal of precancerous polyps during the same procedure.
Screening Interval
After the initial screening, colonoscopies are typically repeated every 10 years for those with normal results and no polyps found. This interval may vary based on individual risk factors and the findings of the initial screening.
Importance of Screening
Regular screening is crucial because colorectal cancer often develops slowly from precancerous polyps, and when caught early, has excellent treatment outcomes. The preparation for colonoscopy involves a complete bowel cleansing the day before the procedure, typically using prescribed laxatives, and the procedure itself usually takes 30-60 minutes with sedation provided for comfort.
Recent Guidelines
The most recent study from 2023 1 provides a comprehensive update on the risk stratification for colorectal cancer screening and post-polypectomy surveillance, supporting the recommendation to start screening at age 45 for average-risk individuals. This guideline, published in Gastroenterology, synthesizes recommendations from various practice guidelines, including those from the American Cancer Society, the American College of Gastroenterology, and the US Preventive Services Task Force.
From the Research
Screening Age for Colonoscopy
The recommended age for a screening colonoscopy for individuals at average risk for colon cancer is:
- 45 years old, as suggested by the U.S. Multi-Society Task Force on Colorectal Cancer 2
- This recommendation is based on the increasing disease burden among individuals under age 50 and emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59 2
- Most guidelines recommend screening between 45 and 75 years for average-risk individuals 3
Screening Intervals and Modalities
The suggested screening intervals and modalities are:
- Colonoscopy every 10 years for average-risk individuals 3
- FIT (Fecal Immunochemical Test) annually for average-risk individuals 3
- CTC (Computed Tomography Colonography) every five years for all individuals 3
- The decision to start or continue screening for individuals ages 76 to 85 should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference 2
High-Risk Individuals
For high-risk individuals with a positive family history of colorectal cancer or advanced colorectal polyp, screening should begin at: