This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Screening (for large bowel cancer using FOB tests)

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

A study published by Kronborg et al (Lancet, 1996) revealed that biennial screening with faecal occult blood testing reduced mortality from colorectal cancer.

The study involved 30, 967 adults who were assigned to biennial screening using a guaiac-based FOBT (in this case Haemoccult-II). Patients using the test were advised to have dietary restrictions before the test (no red meat, fresh fruit, iron preparations, vitamin C, or aspirin or other non-steroidal rheumatic drugs for 3 days before testing).

Two other trials (2,3) have also provided evidence that faecal occult blood testing every two years has the potential to reduce mortality by up to 20%.

A further trial by Mendel et al (4) has shown that both annual and biennial faecal occult blood screening reduced the incidence of colorectal cancer. This trial also showed, for the first time, that faecal occult blood screening can decrease both the rate of cancer and the mortality rate.

Notes:

  • two types of faecal occult blood test are now available: the Guaiaco and the Immunochemical test
    • sensitivity and specificity of the two tests are similar and do not clearly indicate which one is better for screening
    • Guaiaco test recommends three different evacuations, and requires the patient to store the samples, and follow dietary restrictions
    • immunochemical test is recommended on a single evacuation and does not require dietary restrictions
    • the associated discomfort and embarrassment of faecal sampling and the dietary restrictions have been hypothesized to be determinants of noncompliance (5)
  • the dimeric isoenzyme of pyruvate kinase, M2-PK, expressed by tumor cells, has as well been proposed as a screening tool for colorectal cancer
    • however the office-based immunochemical faecal occult blood test was found to have significantly higher specificity, positive predictive value, and positive likelihood ratio as compared with M2-PK (6)

Reference:


Related pages

Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.