Download USE AND CHOICE OF FAECAL OCCULT BLOOD TEST (FOBT)

Use and Choice of Faecal Occult Blood Tests (FOBT)
The purpose of this document is to give a succinct overview of the use and choice of faecal
occult blood tests for screening of colorectal cancer. These points may not apply to other
settings, e.g. patients with iron deficiency.
1.
RECOMMENDATIONS:
1)
2)
Request screening FOBT, preferably an immunochemical test (FIT, see notes).
Encourage the screenee:to follow the test instructions on sampling and on dietary
restrictions (if a guaiac test) –these will come from with the test kit.
Notes:
 Ideally, the pathology laboratory will use a reliable guaiac test (eg. Hemoccult
SENSA) or an established faecal immunochemical test (FIT). You cannot easily
control which they choose. If they provide both, it is acceptable to act on the basis of
the immunochemical test only when screening.
 A Medicare rebate might not apply if the laboratory reports only the FIT..
 Tests can be purchased. Detectacol is available through chemists, Insure (Enterix)
and Eiken Bowel Check are available from general practices and/or online .
2.
RATIONALE
2.1
Types of FOBT - There are two types:
Chemical tests (gFOBT)- Only those based on guaiac are reliable and by far the best
evaluated type are the readily available Hemoccult tests (Hemoccult II and
Hemoccult SENSA).
Immunochemical tests (FIT, iFOBT). These are sometimes referred to as faecal
human haemoglobin (FHH) tests. Examples include Eiken Bowel Check,
Hemeselect, HemSP, Detectacol, Hemoccult ICT, InSure and Hemolex.
Availability of these varies greatly.
Please note: When using an FOBT for screening, only one should be used even though the
Medicare rebate only reimburses Using two for screening causes problems of specificity and
causes too many “false positives”.
2.2
Key Points on FOBT Types
Guaiac tests (FOBT, detect haem or peroxidase in faeces).
Site of bleeding – can detect bleeding from stomach/small intestine as well as
from colon/rectum but are more sensitive for bleeding from the latter.
Diet/Drug interference – high dietary levels of plant peroxidases and red meat
(haem therein) can cause false positives, and high dose vitamin C can cause
false negatives.
Immunochemical tests (FIT, detect human haemoglobin using antibody
technology).
Site of bleeding – will only detect occult bleeding from the colon/rectum (nonhuman haemoglobin is not detected, haemoglobin from upper GI is degraded)
Diet/Drug interference – none.
Conclusion: FITs are unaffected by diet and are more selective for colorectal bleeding.
Research also indicates that screenees are more willing to do them than guaiac tests.
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Use and Choice of Faecal Occult Blood Tests (FOBT)
2.3
2.4
FOBT Type Availability (and problems)

The guaiac-based Hemoccult tests are easily available and cheap (a few
dollars). Hemoccult SENSA is more sensitive and more easily read than
Hemoccult II.

FITs vary in availability, usage by pathology laboratories, cost and quality of
clinical data supporting their use. InSure is easily available from many general
practices or direct from Enterix Australia (phone or web site) for around $30
and there is a growing body of published clinical performance data for InSure.
Eiken Bowel Check is available online. Of tests available, through pathology
laboratories in Australia, the most used seem to be Hemolex and Detectacol.
Clinical data supporting these tests are not strong at an international level but
Detectacol in SA appears to perform fairly well. Other FITs with strong
international clinical data (eg HemSp, Hemoccult ICT) remain somewhat
expensive and are quite difficult to get.
FOBT Usage
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3.
Ideally test by just one type of FOBT.
Always sample at least two separate stool motions (not necessarily
sequential).
The screenee should do the sampling at home according to instructions (do not
take samples at rectal examination).
For guaiac tests, dietary restrictions should be followed and commenced 72h
prior to sampling.
PROBLEM HOTLINE
SCOOP Program FMC: Karen Saxty 8204 8902 (Tel); 8204 8971 (Fax)
SCOOP Program RGH: Kalindra Simpson/Michelle Coats, 8275 1745 (Tel); 8275 1083 (Fax)
RGH Bowel Health Service: Mr Steve Cole, 8275 1838 (Tel); 8275 1756 (Fax)
Prof Robert Fraser
Regional Head of Gastroenterology & Hepatology
Medicare: To receive your rebate from Medicare you must return the pathology form given to you by your GP with
the test card. The pathology lab will lodge the Medicare rebate with Medicare Australia on your behalf and you will
receive a cheque in the mail.
Please note: there is an additional $15.40 pathology fee which is payable to the pathology lab when returning your
sample test card. This is the portion that may be claimable on Medicare.
From http://www.pharmacyonline.com.au/bowelscreen-australia-bowel-cancer-screening-test-customers-inaustralia-only/
The Minister has directed that Medicare benefits be paid for the following categories of health
screening:
a medical examination or test on a symptomless patient by that patient's own medical
practitioner in the course of normal medical practice, to ensure the patient receives any
medical advice or treatment necessary to maintain their state of health. Benefits would
be payable for the attendance and tests which are considered reasonably necessary
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Use and Choice of Faecal Occult Blood Tests (FOBT)
according to patients individual circumstances (such as age, physical condition, past
personal and family history).
From
http://www9.health.gov.au/mbs/fullDisplay.cfm?type=note&q=G13.1&qt=noteID&crit
eria=bowel%20cancer%20screening
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