From the Guidelines
Colorectal cancer screening is recommended for average-risk adults starting at age 45, with colonoscopy every 10 years being the gold standard screening method. This recommendation is based on the most recent and highest quality evidence from the American College of Physicians, which suggests that colonoscopy every 10 years or annual fecal immunochemical test (FIT) are first-tier options for screening average-risk persons for colorectal neoplasia 1. Alternative screening options include stool-based tests such as FIT annually, multi-target stool DNA test (Cologuard) every 3 years, or CT colonography every 5 years.
Key Considerations
- The U.S. Multi-Society Task Force on Colorectal Cancer recommends offering CRC screening beginning at age 50, but suggests that screening begin in African Americans at age 45 years 1.
- Individuals with a family history of colorectal cancer, personal history of inflammatory bowel disease, or genetic syndromes like Lynch syndrome should begin screening earlier and may require more frequent examinations.
- Screening is generally continued until age 75, with individualized decisions for those 76-85 years old based on overall health and prior screening history.
Screening Methods
- Colonoscopy every 10 years: allows for direct visualization of the entire colon and removal of precancerous polyps during the same procedure.
- Fecal immunochemical test (FIT) annually: a stool-based test that detects blood in the stool.
- Multi-target stool DNA test (Cologuard) every 3 years: a stool-based test that detects DNA mutations associated with colorectal cancer.
- CT colonography every 5 years: a radiographic test that visualizes the colon and detects polyps and cancer.
Importance of Screening
Colorectal cancer is highly preventable through regular screening, as the slow progression from polyps to cancer provides an opportunity for early detection and removal of precancerous lesions. Regular screening can reduce the incidence and mortality of colorectal cancer, and improve quality of life for individuals with the disease.
From the Research
Recommended Screening for Colon Exams
The recommended screening for colon exams varies depending on the individual's risk level.
- For average-risk individuals, screening is recommended between 45 and 75 years of age 2.
- For high-risk individuals, such as those with a positive family history of colorectal cancer, screening should begin at age 40 2.
Screening Modalities
Several screening modalities are recommended, including:
- Colonoscopy: every 10 years for average-risk individuals and every 5-10 years for high-risk individuals 2.
- Fecal Immunochemical Test (FIT): annually for average-risk individuals and every 1-2 years for high-risk individuals 2.
- Computed Tomographic Colonography (CTC): every five years for all individuals 2.
Effectiveness of Screening Modalities
Studies have compared the effectiveness of different screening modalities, including:
- Colonoscopy vs. FIT: a randomized controlled trial found that colonoscopy had a higher detection rate of advanced tumors compared to FIT 3.
- Immunochemical FOBTs (iFOBT) vs. guaiac-based FOBTs (gFOBT): a systematic review and meta-analysis found that iFOBTs had a significantly higher diagnostic performance compared to gFOBTs 4.
Risk-Graded Screening Strategies
A risk-graded screening strategy, which combines colonoscopy and FIT, has been found to be effective in colorectal cancer screening 3.
- This strategy involves risk assessment, with high-risk individuals receiving colonoscopy and low-risk individuals receiving FIT.
- The strategy has been found to improve screening accuracy and early detection rates, and can be used as an effective supplement to traditional colonoscopy and FIT screening programs 3.