1. Presented by Dr Heather Murray GPEP1 Registrar on behalf of
Does screening for CRC with FOBT reduce overall mortality? OTC FOBT kits – how to advise patients?
Presented by Dr Heather Murray GPEP1 Registrar on behalf of
Dr Prakash Appanna, Dr Vinodha Naidoo, Dr Shadi Gadalla and Dr Heather Murray
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

2. Aims and Methods AIMS 1) Review evidence base for test
2) How to advise patients on OTC Screening Test Kits
3) Effect of FOBT screening on overall mortality
METHODS
Literature review
'Summon' database
Information from Enterix
producers of Insure FOB Test
Visit & phone discussion
pharmacies selling kit
Personal correspondence
labtests chemical pathologist
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

3. Why screen for CRC?
High rates in NZ and rest of world, especially >50 years and males
Earlier detection = better outcomes
FOBT is the method with the most research available on population screening
No screening programme in NZ yet – but pilot study due to start in WDHB soon
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

4. FOBT performance
Immunochemical test shows better performance – but no test = 100% sensitive or specific
Test available in pharmacies for $60 (InSure iFOBT), not through labtests
Recommended for patients >50 years
Concerns about the information presented to the public
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

5. Effect on mortality? FOBT screening can prevent 1 in 6 CRC deaths
No trials demonstrate reduction in overall mortality
Some suggest increased mortality – controversial
Recommend further research into this
Note no trial data for effect on mortality of iFOBT
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

6. What about harms of screening?
Colonoscopy complications - perforation, bleeding, surgery, death
Pilot studies demonstrated low complication rates – under trial conditions in 'expert centres'
False positives and anxiety
Need to consider whether benefit outweighs potential risk – selected populations eg >50yrs
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

7. How to advise patients?
Ensure patients are fully informed – risks and benefits, interpretation of results
Access to colonoscopy – will they qualify if positive?
Bottomline = informed choice
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

8. Key Messages
1) Direct to consumer screening is not the same as an organised national screening programme
- why does the patient want the test?
2) Positive test does not necessarily = CRC or eligibility for public colonoscopy
- false positives + negatives
- Auckland regional colonoscopy guidelines do not include asymptomatic patients <50yrs with no risk factors or family history
3) No evidence of reduction in overall mortality, with potential increase
4) Proposed iFOBT for NZ screening has limited evidence to demonstrate effect on mortality
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

9. References
1) Ballinger et al, “Colorectal Cancer”, BMJ 2007;335:715-8.
2) Shaw et al, “Next steps for a feasibility study for colorectal cancer screening in New Zealand: Report for the Ministry of Health”, Department of Public Health, University of Otago, Wellington, 2008.
3) Zhu et al, “Comparsion of immunochemical and guaiac-based fecal occult blood test in screening and surveillance for advanced colorectal neoplasms: A meta-analysis”, Journal of Digestive Diseases 2010;11;
4) Personal correspondence with Dr Jeffrey Barron, chemical pathologist at LabTests Auckland.
5) Labtests patient instructions
6) Hol et al, “Screening for colorectal cancer: randomised trial comparing guaiac-based and immunochemical faecal occult blood testing and flexible sigmoidoscopy”, Gut 2010;59:62-68.
7) Smith et al, “Comparison of a brush-sampling fecal immunochemical test for hemoglobin with a sensitive guaiac-based fecal occult blood test in detection of colorectal neoplasia”, Cancer 2006;107;9:
8) Towler et al, “A systemic review of the effects of screening for colorectal cancer using the faecal occult blood test, Hemoccult”, BMJ 1998;317:
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ

10. References (contd)‏
9) Rembold, “Number needed to screen: development of a statistic for disease screening”, BMJ 1998;317:
10) BowelScreen Aotearoa health professional information
11) Hewitson et al, “Screening for colorectal cancer using the faecal occult blood test, Hemoccult”, Cochrane Database of Systematic Reviews 2007, Issue 1. Art.No.:CD DOI: / CDO pub2. (2011 update).
12) Moayyedi et al, “Does fecal occult blood testing really reduce mortality? A reanalysis of systematic review data” Am J Gastroenterol 2006;101:380–384.
13) Zappa et al, “Letters to the editor: “Does fecal occult blood testing really reduce mortality? A reanalysis of systematic review data” and author's response”, Am J Gastroenterol 2006;101:
14) Colorectal Cancer Screening Advisory Group, “Report of the Colorectal Cancer Screening Advisory Group”, Ministry of Health 2006;1-160.
15) Lindholm et al, “Worry associated with Screening for Colorectal Carcinomas”, Scand J Gastrocntcrol 1997;32:
16) WHO criteria for screening,
(C) August Onewa Road Doctors Limited presented to the 2011 Conference for General Practice, Auckland, NZ