Can patients at high risk for significant colorectal neoplasms and having normal quantitative faecal occult blood test postpone elective colonoscopy?

Aliment Pharmacol Ther. 2010 Feb 15;31(4):523-33. doi: 10.1111/j.1365-2036.2009.04202.x. Epub 2009 Nov 19.


Background: Common reasons for elective screening and surveillance colonoscopy, at predetermined intervals, are family or personal history of colorectal cancer (CRC) or advanced adenoma (AAP). Quantified, human haemoglobin (Hb)-specific, immunochemical faecal occult blood tests (I-FOBT) detect bleeding.

Aim: To determine I-FOBT sensitivity for CRC or AAP before elective colonoscopy in patients at high-risk of cancer or advanced adenoma.

Methods: Prospective double-blind study of 1000 ambulatory asymptomatic high-risk patients (555 family history of CRC, 445 surveillance for past neoplasm), who prepared three I-FOBTs before elective colonoscopy. I-FOBTs quantified as ngHb/mL of buffer by OC-MICRO instrument and results >or=50 ngHb/mL considered positive.

Results: At colonoscopy, eight patients had CRC, 64 others had AAP. Sensitivity for CRC and/or AAP was the highest, 65.3% (95% CI 54.3, 76.3), when any of the three I-FOBTs was >or=50 ngHb (15.4%), with specificity of 87.5% (95% CI 86.4, 90.5) identifying all CRCs and 62% of AAPs.

Conclusions: All cancers or an AAP were detected every third I-FOBT-positive colonoscopy (47/154), so colonoscopy was potentially not needed at this time in 84.6% (846 patients). I-FOBT screening might provide effective supervision of high-risk patients, delaying unnecessary elective colonoscopies. This favourable evaluation needs confirmation and cost-benefit study by risk-group.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / diagnosis*
  • Colonoscopy / statistics & numerical data*
  • Colorectal Neoplasms / diagnosis*
  • Colorectal Neoplasms / genetics
  • Disease Susceptibility
  • Epidemiologic Methods
  • Female
  • Hemoglobins / analysis*
  • Humans
  • Immunohistochemistry / methods
  • Male
  • Mass Screening / methods
  • Middle Aged
  • Occult Blood*


  • Hemoglobins