From the Guidelines
The recommended age to start colonoscopy screening for average-risk individuals is 45 years old. This is based on the most recent and highest quality study from the US Multi-Society Task Force on Colorectal Cancer, published in 2022 1. The study suggests that average-risk CRC screening begin at age 45, due to increasing CRC incidence and mortality in younger adults.
Key Considerations
- The age recommendation was lowered from 50 to 45 in recent years due to increasing rates of colorectal cancer in younger adults, as supported by the American Cancer Society, 2018, and the National Comprehensive Cancer Network, 2022 2.
- For those with a family history of colorectal cancer or advanced polyps in a first-degree relative, screening should begin either at age 40 or 10 years before the age at which the relative was diagnosed, whichever comes first, as recommended by the US Multi-Society Task Force on Colorectal Cancer, 2022 1.
- People with certain genetic syndromes (like Lynch syndrome), inflammatory bowel disease, or a personal history of colorectal cancer or certain types of polyps may need to start screening earlier and have more frequent examinations.
- African Americans have historically had higher rates of colorectal cancer and may benefit from discussing earlier screening with their healthcare provider.
Screening Frequency and Duration
- Screening should continue periodically until age 75, with most people needing a colonoscopy every 10 years if results are normal, as recommended by the US Preventive Services Task Force, 2021 2.
- The decision to initiate or continue screening after age 75 should involve a shared decision-making process between a patient and provider that considers prior screening history, life expectancy, CRC risk, and patient preferences, as suggested by the US Multi-Society Task Force on Colorectal Cancer, 2022 1.
- Individuals ages 86 and older should not be offered CRC screening, as the overall mortality risk and risk of adverse events associated with colonoscopy outweigh the life expectancy benefits, as stated by the US Multi-Society Task Force on Colorectal Cancer, 2022 1.
From the Research
Age to Start Colonoscopy
- The age to start colonoscopy varies depending on the individual's risk level, with most guidelines recommending screening between 45 and 75 years for average-risk individuals 3.
- For high-risk individuals with a positive family history of colorectal cancer or advanced colorectal polyp, screening should begin at age 40 3.
- There is no direct evidence in the provided studies to suggest a specific age to start colonoscopy for all individuals, but the studies suggest that colonoscopy is an effective screening method for detecting colorectal cancer and advanced neoplasms 4, 5, 6, 7.
Screening Modalities and Intervals
- Several screening modalities are suggested, including colonoscopy, fecal occult blood test (FOBT), and computed tomographic colonography (CTC) 3, 4, 5, 6, 7.
- The recommended screening intervals vary, with colonoscopy every 10 years for average-risk individuals and every 5-10 years for high-risk individuals, FOBT annually for average-risk individuals and every 1-2 years for high-risk individuals, and CTC every five years for all individuals 3.
Effectiveness of Screening Methods
- Studies have shown that colonoscopy, FOBT, and flexible sigmoidoscopy are effective in reducing colorectal cancer mortality 4, 5, 6, 7.
- The comparative effectiveness of these tests on colorectal cancer mortality has been evaluated, with flexible sigmoidoscopy and FOBT showing a reduction in mortality, but the evidence is indirect and of low quality 7.