What are the current colon cancer screening recommendations?

From the Guidelines

Colon cancer screening is recommended to begin at age 45 for average-risk individuals. The preferred screening methods include colonoscopy every 10 years, stool-based FIT (fecal immunochemical test) annually, or stool DNA testing (like Cologuard) every 3 years, as suggested by the US Preventive Services Task Force 1. For colonoscopy preparation, patients typically use bowel cleansing solutions like GoLYTELY, MoviPrep, or SUPREP the day before the procedure, following a clear liquid diet.

Key Considerations

• Screening should continue until age 75, after which the decision to screen should be individualized based on health status and life expectancy, with a general consensus that screening should stop after age 85 years 1.
• People with higher risk factors, such as a family history of colorectal cancer, personal history of inflammatory bowel disease, or certain genetic syndromes, may need to start screening earlier and undergo more frequent testing.
• African Americans also have higher colorectal cancer rates and may benefit from earlier screening, with the US Multi-Society Task Force recommending beginning screening at age 45 years in Black adults (weak recommendation) 1.

Screening Recommendations

• The American College of Gastroenterology suggested screening in average-risk persons aged 45 to 49 years (conditional recommendation) and recommended screening average-risk persons aged 50 to 75 years (strong recommendation) 1.
• The American Cancer Society (ACS) recommended that screening begin at age 45 years in all adults (qualified recommendation) 1.

Importance of Screening

These recommendations aim to detect precancerous polyps or early-stage cancer when treatment is most effective, as colorectal cancer typically develops slowly over years from precancerous growths, making it highly preventable through regular screening 1.

From the Research

Colon Cancer Screening Recommendations

The current recommendations for colon cancer screening are based on various studies and guidelines.

• The American College of Gastroenterology and other organizations recommend that adults aged 50-75 years undergo regular screening for colorectal cancer using one of several tests, including colonoscopy, fecal occult blood tests (FOBT), or stool DNA tests 2, 3, 4, 5, 6.
• The choice of screening test depends on various factors, including the patient's risk factors, medical history, and personal preferences.
• Colonoscopy is considered the gold standard for colon cancer screening, but it is an invasive procedure that requires preparation and sedation.
• FOBT, on the other hand, is a non-invasive test that can be performed at home, but it has a lower sensitivity and specificity compared to colonoscopy.

Fecal Occult Blood Tests (FOBT)

FOBT is a type of screening test that detects blood in the stool, which can be a sign of colon cancer.

• There are two types of FOBT: guaiac-based FOBT (gFOBT) and immunochemical FOBT (iFOBT) 2, 5.
• iFOBT is more sensitive and specific than gFOBT, and it is recommended as the preferred type of FOBT for colon cancer screening 5.
• The sensitivity and specificity of FOBT vary depending on the type of test and the cutoff level used, but it is generally lower than that of colonoscopy 2, 5, 6.

Risk-Graded Screening Strategies

Risk-graded screening strategies involve classifying individuals into different risk categories based on their medical history, family history, and other factors.

• A study published in 2024 found that a risk-graded screening strategy using colonoscopy and iFOBT can improve screening accuracy and early detection rates, while reducing the number of colonoscopies required 4.
• The study found that the graded screening group had a higher detection rate of advanced tumors compared to the FIT group, but not compared to the colonoscopy group.

Quantitative Immunochemical Fecal Occult Blood Test (qFIT)

qFIT is a type of FOBT that measures the level of fecal hemoglobin in the stool.

• A study published in 2019 found that qFIT has an acceptable sensitivity and specificity for detecting advanced colorectal neoplasia, and that the results are associated with the location and size of adenomas as well as the grade of CRC 6.
• The study found that the best cutoff level for qFIT was 400 ng/mL for advanced colorectal neoplasia and 500 ng/mL for CRC.