What are the available options for colon cancer screening?

From the Guidelines

Colon cancer screening is recommended for adults aged 50 years and older, with several effective options available, including colonoscopy every 10 years, annual high-sensitivity guaiac fecal occult blood testing (gFOBT) or fecal immunochemical testing (FIT), stool DNA testing, flexible sigmoidoscopy every 5 years, double-contrast barium enema every 5 years, and CT colonography every 5 years. The available options for colon cancer screening can be categorized into two groups: tests that primarily detect cancer and tests that can detect cancer and advanced adenomas. The tests that primarily detect cancer include guaiac fecal occult blood testing (gFOBT) and fecal immunochemical testing (FIT), as well as testing stool for exfoliated DNA (sDNA) 1. The tests that can detect cancer and advanced adenomas include endoscopic examinations such as flexible sigmoidoscopy (FSIG), colonoscopy, and radiological examinations like double-contrast barium enema (DCBE) and computed tomography colonography (CTC) 1. It is essential to note that while all recommended tests are acceptable options, the prevention of colorectal cancer is the greater priority in screening, and the best screening test is the one that gets done, so patient preference and adherence should guide selection 1. Some key points to consider when choosing a screening option include:

• Individual risk factors, such as a history of adenomatous polyps or a personal history of curative-intent resection of colorectal cancer
• Personal preference and access to screening options
• The sensitivity, specificity, and preparation requirements of each screening method
• The need for follow-up colonoscopy after positive results from non-colonoscopy tests Regular screening is crucial because colon cancer is highly treatable when detected early, with most cases developing from precancerous polyps that can be removed before becoming malignant 1.

From the Research

Available Options for Colon Cancer Screening

The available options for colon cancer screening can be categorized into several tiers based on performance features, costs, and practical considerations.

• First-tier tests include:
  • Colonoscopy every 10 years 2
  • Annual fecal immunochemical test (FIT) 2, 3
• Second-tier tests include:
  • CT colonography every 5 years 2
  • FIT-fecal DNA test every 3 years 2
  • Flexible sigmoidoscopy every 5 to 10 years 2, 4, 5
• Third-tier tests include:
  • Capsule colonoscopy every 5 years 2
• Other screening options include:
  • High-sensitivity guaiac fecal occult blood test (HSgFOBT) 3
  • Multi-target stool DNA (mt-sDNA) test 3
  • Computed tomographic (CT) colonography (virtual colonoscopy) 3
  • Flexible sigmoidoscopy with FIT 3
  • Traditional colonoscopy 3
  • Blood-based screening or "liquid biopsy" (emerging and novel) 3
  • Colon capsule endoscopy (emerging and novel) 3, 6
  • Urinary metabolomics (emerging and novel) 3
  • Stool-based microbiome testing (emerging and novel) 3

Recommendations for Screening

The recommendations for screening vary depending on the individual's risk level and age.

• Average-risk individuals should undergo screening between ages 50 and 75 using colonoscopy, flexible sigmoidoscopy, or fecal occult blood test (FOBT) 4, 5
• Screening should begin at age 45 for African Americans 2
• Individuals with a family history of CRC or a documented advanced adenoma in a first-degree relative should undergo screening by colonoscopy every 5 years, beginning 10 years before the age at diagnosis of the youngest affected relative or age 40, whichever is earlier 2
• Discontinuation of screening should be considered when individuals up to date with screening, who have prior negative screening (particularly colonoscopy), reach age 75 or have <10 years of life expectancy 2