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Pathology in the UK Bowel Cancer Screening Programmes. Frank Carey (Dundee). Screening for Large Bowel Cancer. Faecal occult blood (FOB) Guaiac Immunological Sigmoidoscopy Colonoscopy CT Colography. FOB Screening for colorectal Cancer. The research The pilot The programmes Pathology .
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Pathology in the UK Bowel Cancer Screening Programmes Frank Carey (Dundee)
Screening for Large Bowel Cancer • Faecal occult blood (FOB) • Guaiac • Immunological • Sigmoidoscopy • Colonoscopy • CT Colography
FOB Screening for colorectal Cancer • The research • The pilot • The programmes • Pathology
The Research • Population screening with FOB + colonoscopy reduces disease-specific mortality from colorectal cancer • Mandel et al N Engl J Med 1993 • Kronborg et al Lancet 1996 • Hardcastle et al Lancet 1996
Meta-Analysis of FOBT Trials • Overall relative risk of death • 0.84 (CI 0.77 - 0.93) • 16% reduction in deaths • Adjusted for uptake • 0.77 (CI 0.57 - 0.89) • 23% reduction in deaths (Towler et al 1998)
Effect of Screening on Colorectal Cancer Incidence Control group Screened groups
UK Pilots (2000 onwards) • Aim: to test feasibility of screening in “real life” NHS • Coventry and Warwickshire • Fife, Grampian and Tayside (each with approx. 1m pop.)
Operation of Pilots • Central call/recall, administration, helpline • Postal delivery of FOB kits • Analysis in newly constructed labs (run by Biochemistry) • Minimum primary care involvement • Screening Group (lead clinician, surgery, pathology, biochemistry, nursing, public health, radiology)
Screening Pilot Start date: 29 March 2000 • Postal delivery of test kit from Centre • One reminder test kit • Dietary restriction for weak positive • Nurse interview • Colonoscopy
UK First Round Screening Algorithm Guaiac FOBT WP [1-4 spots positive] P [5-6 spots positive] Retest WPN WPP [any spot P] Retest Investigation WPNP [any spot P] WPNN Repeat tests had dietary restriction
Key Performance Indicators (KPIs) • Uptake • overall • by deprivation category • response rate to first invitation • response rate to reminders • Time to colonoscopy • Proportion of +ves undergoing colonoscopy • Colonoscopy completion rate • Colonoscopy complication rate • admissions • perforations • bleeding • deaths • Positivity rate • Cancer Detection Rate • Stage at diagnosis (incl. polyp cancers) • Adenoma detection rate • overall • high risk • PPV • for cancer • for adenoma • for high risk adenoma • for any neoplasia
Age and Sex Uptake, % Age range
Deprivation Category Uptake, % SIMD
KPI 3(Proportion of FOBT positive individuals undergoing colonoscopy) (provisional)
KPI 4(Colonoscopy completionrate) (provisional)
KPI 6(FOB positivity) (provisional)
KPI 7(Cancer detection rate /1000 screened) (provisional)
Stage Distribution of Symptomatic Colorectal Cancer A 8% D 25% B 33% C 34%
Stage Distribution of Screen -Detected Cancers D 1% True A 26% C 26% 48% B 25% Polyp Cancers 22%
Meaning of FOBT + • Initial positivity 2%. Of these; • 40% have neoplasia (30% adenoma 10% cancer) • 10% have something else (eg inflammatory bowel disease)
Colonoscopy Activity at Ninewells Hospital (by quarter) Start of screening
Workload change in Ninewells pathology *Overall effect on colorectal specimen number is not large
First NHS screening colonoscopy • Asymptomatic solitary sigmoid polyp (11mm) • Complete excision of moderately differentiated adenocarcinoma (no lymphatic/vascular invasion)
All Cancers – Screened Health Boards P<0.01 54% 48% 42% 37% * Screening will save 150 lives per year in Scotland
Cancers in a screened population • Screen detected • Interval cancers (about half of all cancers in screened population in Nottingham) • After negative FOB • After positive FOB/negative colonoscopy • Cancers in those refusing FOB screening
Polyps bleed…….. • About 2900 polyps were removed in the Scottish Pilot 1st round • Vast majority hyperplastic polyps or adenomas
Adenomas in Screening • Adenomas much more common than cancers • Adenomas are the precursors of most cancers • Adenomas (even when removed) are a marker of cancer risk • The programme is almost as much about adenomas as cancer
Interval Cancers(All cancers diagnosed in the population who responded to the 1st round screening invitation within 2 years of their FOBT result)
Adenoma Follow-up Scheme Low risk 1 or 2 small adenomas <10mm Intermediate risk 3 or 4 adenomas or, at least one >10mm High risk (1) 5 or more adenomas or, At least three >10mm High risk (2) Large sessile adenoma removed piecemeal A B C D Colonoscopy at 3 years Colonoscopy at 1 year Check eradication at three months ?re-treat D ? needs surgery Surveillance by FOBt * (or exceptionally colonoscopy at 5 years) • Findings at follow up: • No adenomas B • No adenomas x 2 cease follow up • Intermediate or high risk B or C • Findings at follow up: • No adenomas B • Intermediate or low risk B • High risk C • Inspect at 1 year • No adenoma B Notes: Low risk adenomas: Patients in whom one or two small tubular adenomas are removed are at no significant additional risk of developing colonic cancer, and may have a reduced risk of developing rectal cancer, when compared with the unexamined population. Surveillance by FOB testing within the screening programme is recommended. Polyp cancers- Histology should be reviewed and further management discussed at an appropriate Multi-Disciplinary Team meeting. If surgical resection is not indicated then the patient should be followed in the high risk category
Bowel Screening Programmes • England – initially 60-69 years (pilot was 50-69) • Scotland – 50-74 years* • Wales – in planning stages • N. Ireland – no immediate plans *Peak incidence is approximately 72 years
Programme Organisation • England: • Screening hubs provide call/recall, FOB laboratory, facilitate polyp surveillance • Screening centres provide nurse clinics, colonoscopy, pathology, cancer treatment • Scotland: • Central FOB laboratory, call/recall centre in Dundee. All other activity devolved to local NHS Boards
Funding • New funding available in England (including allocation for pathology) • Funding contingent on gathering of agreed datasets • No additional funding in Scotland
Pathology • Make a diagnosis • Plan treatment and follow up • Collect accurate data • Audit of service development • Facilitate high quality research
Applied research • Effect of programme on mortality • Diagnostic accuracy in early cancers • Prognosis in screen detected early stage cancer • Polyp cancers • Interval cancers • Cancers in those declining screening • Follow-up of adenomas • Does adenoma removal reduce the incidence of cancer Resource includes data andtissue (for molecular and immunohistochemical study)
UK Bowel Screening Programs • Probably the best database on adenoma and early colorectal cancer in the world • A major opportunity
FOBtTechnology • Traditional guaiac tests • Hemoccult, Hema-screen, ColoScreen • Sensitive guaiactests • Hemoccult Sensa, ColoScreen ES • Immunochemical tests • InstantView, immunoCARE, Hemosure,Inform, Confirm, Hemascreen Specific