Dr Alasdair Patrick Gastroenterologist

Transcription

1 Dr Alasdair Patrick Gastroenterologist

2 Bowel Cancer screening Dr Alasdair Patrick Gastroenterologist MacMurray Gastroenterology

3 Case- Patient for Screening? 62 year old lady Father diagnosed with advanced bowel cancer at aged 65 and died in 6 months Long history of IBS No alarm symptoms What would you do????

4 Options A Nothing B FOB C CT colon D Colonoscopy E Refer for opinion

5 Overview Epidemiology Current situation in NZ Options for screening Stool tests Radiology Endoscopy Future Directions Summary

6 Epidemiology of Bowel cancer Most common cancer diagnosed in NZ 2890 diagnosed in deaths NZ has 3 rd highest death rate in OECD Maori less likely to be diagnosed and more likely to die Screening proven to reduce death rates

7 Age related risk

8 Age specific CRC risk in NZ population Age next 5 years Risk (%) end 5 years Cumulative risk (%) period

9 Screening- Current situation in NZ If first degree relative under aged 55 or two first degree relatives on same side 10 years earlier a colonoscopy 5 yearly from 50 Stop at age 75 USA, UK, Australia, Italy, France, Canada Have population bowel cancer screening

10 Current situation in NZ May 2008 Minister of Health announces a screening program will be established Likely to be FIT testing Endoscopy services struggling already Predicted about 1/3 increase in colonoscopy demand from screening 65% increase in resources

11 Current situation in NZ May year pilot announced to begin DHBs year olds for 2 yearly ifobt If positive get colonoscopy $24 million

12 Predicted costs of screening Estimated $60m per year Cervical cancer $20m Breast cancer $40m Cost will be Postal ifobt National database Increased endoscopy services

13 Definition of a screening A strategy used in a population to detect a disease in individuals without signs or symptoms of that disease Aim is to detect early disease to enable timely intervention and therefore lower mortality and morbidity

14 83% 65% 35% 100% 3-5%

15 Logic It is logical that we should aim to detect and treat polyps and not cancer!

16 Options for screening! 1 Detect cancer Stool tests Most polyps never bleed 2 Detect pre-cancerous lesions CT colonography Colon capsule Colonoscopy

17 Detecting cancer: Stool samples Fecal occult blood (FOB) 4/100 are equivocal False positive dramatically increase the cost 2/100 are abnormal Sensitivity for cancer less than half Gives false reassurance it is a crap test

18 UK FOB based screening program Results in reduction in CCC mortality of 16% (RR 0.84, CI ) If 10,000 people offered, 2/3 uptake=8.5 deaths prevented in 10 years Cost dramatically increased with false positive requiring colonoscopy

19 Detecting cancer: Stool samples Fecal immunochemical test (ifobt) Detects the globin part of Hb Higher sensitivity (approximately 70%) Less false positives Does not pick up polyps This is what we will get in NZ screening

20 Australia based ifobt Detect 70% of cancers and reduce deaths by 36% Predicted to save lives in NZ per year!

21 Options for screening! 1 Detect cancer Stool tests Most polyps never bleed 2 Detect pre-cancerous lesions CT colonography Colon capsule Colonoscopy

22 Detecting pre-cancer: CT colonography

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24 Examples of CTC

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26 CTC Potential advantages Unsedated Safe no perforation with CO2 100% caecal visualisation, >99% mucosal visualisation Stricture fly-through Potential disadvantages Radiation dose 2-3mSv Radiology also stretched Bowel prep required Extra-intestinal findings

27 CTC history Conflicting publications Pickhardt PJ et al NEJM asymptomatic adults V3D/OC Sensitivity 94% polyps > 8mm, 89% > 6mm One extra Cancer detected on V3D Cotton PB et al JAMA symptomatic adults CTC/OC Sensitivity polyps > 10mm 55%, 39% > 6mm Missed 2/8 cancers

28 CTC Reasons for differences Training, hardware, software Meta-analysis Mulhall et al (2005) Heterogeneity raises concerns about consistency of performance Evidence lags behind current technology

29 CTC now! Very contentious Many vested interests Not recommended by the FDA Concerns regarding radiation exposure But Barack Obama had one in February!

30 Colon capsule 4 images/s for 10 hours Delayed activation Colon capsule NEJM recently 328 patients Advanced adenomas 73% Cancers 14/19

31 Colon capsule Main issue is bowel prep Concerns re cost Disposable cost Reading time Colonoscopy may be needed

32 Endoscopy Colonoscopy The gold standard Safe but small risks (1/1000) Diagnostic and therapeutic If started by age 50 reduce CRC by 90%» NEJM 329: 1993 The only recommended method in USA Expensive on a population basis

33 Future directions

34 Stool DNA testing Ongoing studies of various markers p53 Microsatellite instability APC K-ras None validated yet

35 Future directions Fecal DNA Annals of Internal medicine 2008 Mayo clinic 4482 patients in 22 centers Detected 20% of pre-malignant polyps A newer generation test claims 40%

36 Summary Bowel cancer screening is coming next year It will be ifobt 2 yearly from 55 to?70 NOT PERFECT but a great step for NZ Other options Colonoscopy CTC Colon capsule

37 The only comprehensive digestive disease centre in Auckland Consultations in a team environment 5 Gastroenterologists 1 Hepatologist Upper and Lower GI surgeons Dietician Health Psychologist Clinical nurse specialists The only place with full diagnostic and therapeutic services Full endoscopy services BRAVO Capsule endoscopy ph/impedance High resolution Manometry CT colonography and same day colonoscopy if required