ppt
TRANSCRIPT
Bangkok,
Thailand
CanalAVIST Medical Forum
19 September 2008
Title : Colorectal cancer screening, an Asian perspective
Speaker : Dr Taya Kitiyakara Department of
Gastroenterology Faculty of
Medicine Ramathibodi
Hospital, Mahidol
University
Time : 09:00 (TH)
Bangk
ok, Thaila
ndDr Taya Kitiyakara graduated from St Mary’s Hospital,
Imperial College, London 1996 after attending Cambridge University for BA in Medical sciences. He was at
King’s college Hospital, London for his Senior House Officer (residency)
Medical rotation up to 2000.
He trained in Gastroenterology in Oxford, 2000-2007, with one year of liver transplantation at the Royal Prince Alfred Hospital,
Sydney, Australia in 2004.
He has recently started as consultant Gastroenterologist at Ramathibodi Hospital, Mahidol
University, Bangkok, Thailand.CanalAVIST Medical Forum
19 September 2008
Colorectal cancer screening, an Asian perspective
Dr Taya Kitiyakara Dept of gastroenterology
Faculty of medicineRamathibodi hospital
Mahidol University
Content
Incidence Investigations/ screening tests Implementation/ strategies Improvements
Incidence
Incidence of colorectal cancer is high
Second leading cause of cancer death in the West.
Estimated 49,960 deaths in USA, 2008 Jemal et al Cancer J Clin 2008
Incidence of colorectal cancer in Asia
Sung et al Lancet 2005
Increasing incidence of colorectal cancer in Asia
Increasing incidence of colorectal cancer in Asia
– ‘Westernisation’ of diet and lifestyle– Increasing life expectancy
H Sriplung et al 2006
J Ferlay et al 2004KS Chia et al 1995L Yang et al 2004
Increasing mortality from colorectal cancer in Asia
Decreasing mortality in western world
Increasing mortality in Asia
Sung et al Lancet 2005
Mortality rates: men
Mortality rates: women
Screening is appropriate colorectal cancer
Natural history Early detection Treatment available and acceptable Change in outcome
R Rerknimitr et al 2006
Evidence for efficacy of screening
Author type Initial test/ 2nd line
n= f/u (mean)
% CRC reduction
Mandel 1993
RCT FOB/
Colonoscopy46,551 13 yrs 33%
Hardcastle 1996
RCT FOB/
Colonoscopy152,850 7.8yrs 15%
Kronborg 1996
RCT FOB/
Colonoscopy61,833 10 yrs 18%
Winawer et al 1993
Historical controls
Colonoscopy 1418 5.9 yrs 90-76%
EFFICACY OF SCREENING- colonoscopy
Colonoscopy used in all other screening modalities to remove polyps and confirm CRC
Gupta et al 2005
Asia Pacific consensus recommendations
GUT 2008
Investigations and screening tests
Understanding screening
National screening Individual screening
High risk vs. average risk screening
asymptomatic
Tests available for screening
Stool tests– Faecal occult blood (guaiac based)– Faecal occult blood (immunobased)– Stool DNA testing
Imaging tests– Barium tests– CT colonography
Endoscopy tests– Flexible sigmoidoscopy– Colonoscopy
Understanding tests
Tests for (mainly) early cancer– Stool tests
Tests for polyps and cancer– Colonoscopy,– CT colonography,– DCBE
Joint Guideline , US Multi-society task force on colorectal cancer 2008
Stool tests: FOB tests
FOBT sensitivity variable depending on type (high with Hemoccult SENSA)
Higher sensitivity = lower specificity Requires annual/biennial testing Further colonoscopy needed if positive Acceptable test to initiate screening
Detects Collection Cost One-time SENS/SPEC for CRC
gFOB pseudoperoxidase complicated cheap (37-79%) / (87-98%)
FIT Human globin easier More expensive
(65-94%) / (87-97%)
FOB in screening studiesFOB typeN=screened
uptake positive +predictive value
Hardcastle et al, lancet 96
Hemoccultn= 152,850
59.6-38% 2.1% 12% CRC46% neoplasia
Kronborg et alLancet 96
Hemoccult IIn=61,833
67% 1.0% 11% CRC27% adenoma >1cm
Mandel et alNEMJ 93
HemoccultN=46,551
90.2-46% 2.4% 5.6% for CRC
Uk 1st round screen
Hema-screenN=478,000
56.8% 1.9% 10.9% cancer 35% adenoma
Sung et al Gastroent 03
Hemoccult IIN=505
all 20% 8.9% advanced lesions 28.7% neoplasia
Sumetchotimaytha et al 2007
Hema-screen n=20,377
all 12.6% 0.8% CRC3.4% polyps
Li et al Chin Med J 2003
FOBTN= 26,827
74% 35.6% 0.2% CRC0.59% Adenoma
Immunochemical FOB may be better in Asia
FOB+ FIT+ SENS FOB
SENS FIT
SPEC FOB
SPEC FIT
+ predict value FOB
+predict value FIT
Sumetchotimaytha et al 2007
12.6%Hemascreen
12.8% Occultech
0.8% CRC3.4% polyps
1.1% CRC8.9% polyps
Li et al 2003 35.6% 5.6% 0.2% CRC0.6% adenomas
Not specified(at best 1.3% CRC3.7% adenomas)
Wong et al 2007
41% 14% 100% 89% 70% 94% 16% CRC 42% CRC
Cost-effectiveness: Cost of tests + false positive test
Dietary manipulation is thought difficult in many Asian countries
Understanding sensitivity
Per Test sensitivity
(screening) programme sensitivity for test– Repeated chance of detecting lesion– May be better at detecting rapidly growing
cancer compared to an infrequent test
Ransohoff Gastroenterology 2005
Imaging- double contrast barium enema
No RCT/ major trials showing reduction in CRC mortality
Interval not determined
Decreasing use Labour intensive Training issues
Radiation
Superceded by CT colonography
CT colonography
Imaging tests- CT colonography
CT colonography not in Asia Pacific recommendations.
Increasing use/availability More acceptable than
colonoscopy
Extra-luminal imaging
Costly Radiation Flat/ depressed lesions
difficult to image
Criteria needed for best sensitivity:– Excellent bowel prep– Fecal tagging– Cutting edge equipment– Analysis of both 2D and
3D images– Experience of radiologist
Castells Gastroenterology 2008
CT colonography- detection rate
Sensitivity of CT colonography compared to 2 colonoscopies.
2nd colonoscopy aware of all lesions detected from CT and initial colonoscopy
Minimised known miss rate- true sensitivity of CT results
All polyps
>6mm
Neoplastic >6mm
Neoplastic >10mm (n=7)
All polyps All neoplastic
Second colonoscopy
100% 100% 100% 100% 100%
Initial colonoscopy
84%
(69-92%)
91%
(71-97%)
86%
(49-97%)
83%
(74-89%)
87%
(73-94%)
CT colon
(3 observers)
86%
(72-94%)
81%
(60-92%)
100%
(70-100%)
63%
(53-72%)
64%
(48-77%)
Iannaccone et al 2005
Endoscopic tests
Flexible sigmoidoscopy
Decreasing numbers performed in USA ‘incomplete test’ Miss proximal lesions False sense of reassurance
Benefit of cost-effectiveness vs thoroughness may be lost to screenee
Legal implications? Quality of procedure very variable in studies.
Colonoscopy- advantages
‘Complete’ test 10 yr interval Expected 90-70% reduction in CRC
mortality
Colonoscopy- disadvantages Expensive Time and labour intensive May be least acceptable of screening tests Recognised complications Miss rates and interval cancers
Ransohoff Gastroenterology 2005
Miss rates in back-to-back studies
Heresbach et al Endoscopy 2008
Van Rijn et al Am J Gastro 2006
Kaltenbach et al Gut 2008
Iannaccone et al Radiology 2005
Year , n= All polyps Adenomas 5-10mm
Adenomas >10mm or advanced
Systematic review (6 studies)
<2004, n=465 21% 13% 2% (0.3-7.3%)
Multi-centre study
2001-2005, n=286 28% 9% 11%
Double colonoscopy with CT colon
2002-2003, n=88 36% 17% 13% (6-17%)
single centre study vs. NBI
2006-2007, n=142 13% 9.5% 0% (0-1.1%)
Quality control requirements for screening
Bowel prep Training/experience Complete insertion rate Withdrawal time/technique and polyp
detection rate Proper consent Complete polyp removal Timely detection and appropriate
management of complications Follow-up protocol
Joint Guideline , US Multi-society task force on colorectal cancer 2008
Implementation
+ = ?
FOB may be most cost-effective screening test in Asia
Chinese study, Markov model, comparing gFOB, FS, and colonoscopy (population age 50-80yrs)
Colonoscopy used if initial test positive Colonoscopic screening reduced CRC the most (54.1%)
FOB is most cost-effective (then colonoscopy ,then FS) – US$ 6222 /life year saved
FOB remains most cost-effective with different compliance to screening, but not if sensitivity is 30-60%, and specificity is 20-50%
Tsoi et al APT 2008
Large variability in compliance in Asia:Population screening studies
Japan Taiwan China UK 2ND ROUND
France
Health care system
1/3 FIT cost paid by screenee
Combined screening of 5 cancers
Pay system not specified
NHS state funded
State funded
N= 35,602,782 26,008 26,827 127,746 182,274
Test FIT FIT FOB/FIT FOB FOB
Uptake 17% 82% 74% 52.1% 55.4%
Positive test(of returned tests)
7% 5.6% 35.6/5.6% 1.77% 3.4%
%follow up colonoscopy
58% 68% 7.1% 82.8% 87.9%
% with CRC of participants
0.16% 0.19% 0.07% 0.094% 0.23%
Saito 2006Yang et al 2006Li et al 2003Weller et al 2007Denis et al 2007
Compliance, understanding and barriers to screening
Public knowledge of CRC is poor
Lack of time, financial constraints Lack of physician’s recommendation
Lower knowledge about cancer and screening tests less likely to screen
Tests – embarrassing
No health insurance ‘Ostrich’ strategy
Popular support from press and public figures
Sung et al 2008
Ransohoff et al 2005
Resource available?
400 endoscopy units in Thailand
(if FOB Japanese rates from Saito 2006 used )
=126,405 colonoscopies needed
= 316 additional colonoscopies/ unit
Not counting further surveillance colonoscopies needed
Men aged 50-70yrs
4,993,425
Women aged 50-70yr
5,628,906
Total 10,622,331
Total aged 49yrs
821,922
National database 2007Department of Provincial AdministrationMinistry of Interior Thailand
Targeted/ stratification screening
Selective screening for high risk patients?
Increased risk for those with FH of CRC
‘Relaxed’ FH screening guideline may be of benefit
RISK SCORING for deciding initial test
– Using age/ sex/ FH or distal findings
– Reducing number of colonoscopy required by 40%
– Detecting 89-92% of CRCs
Johns et al Am J Gastro 2001
Lin et al Gastroenterology 2006Imperiale et al Ann Intern Med 2003
Subramanian et al Colorectal Dis 2008
Preparation for screening in UK ‘Fitness to scope’
Capacity evaluation Audits
– Complete caecal intubation rate (national)
– Improving endoscopy list efficiency
Global rating score ‘Driving’ test National endoscopy
training centres JAG accreditation Funding incentives
Nnoaham et al Gut 2008
Pickard et al Colorectal dis 2006
Bowles et al Gut 2004Ball et al BMJ 2004
www.grs.nhs.uk
Improvements
New technologies; too new
New endoscopic equipment: – High definition/ Digital chromoendoscopy
eg. NBI (Olympus), i-scan (Pentax) – confocal microendoscopy
Capsule endoscopy (colonic setting)
Fecal DNA
Flat/ depressed lesion detection
Recognised in Japan for many years
Recently accepted in the west Difficult to detect
Higher proportion of high-grade dysplasia/ carcinoma
May be one factor for interval cancers
Muto et al Dis Colon Rectum 1985
Kudo et al World J Surg 2000Soetikno et al JAMA 2008
Rembacken et al Lancet 2000
Improvement in already available techniques
Endoscopic
Patient education
Physician education- referral/ follow-up
General satisfaction
East et al APT 2008
Sung et al Am J Gastro 2008
Turner et al J Gen Intern Med 2003
Endoscopy Units should strive for quality assurance
Audit cycles Local rates eg. for cecal intubation, polyp
detection, interval cancers, complications
Appropriate indication and intervals for procedures according to guidelines (improving cost-effectiveness)
Training in detecting flat polyps Consenting Training trainers/trainees
National programmes should adapt to the country
Resource Geography Patient acceptance/education Healthcare system and infrastructure Funding of screening
More research needed
Evidence to base national programme and Policies– Uptake of each screening modality?– Barriers to screening in each country?– Dietary restrictions for FOB possible?– Possibility of mixed strategies or targeted
screening?– Pilot studies.– Increase in number of colonoscopist/ pathologist/
surgeons needed?
Summary
Incidence of colorectal cancer in Asia in rising
Screening reduces mortality from CRC
Screening tests available include FOB, CT colonography, colonoscopy
Per-test sensitivity vs per- programme sensitivity (which require infrastructure to ensure repeat testing)
Summary
Education, reduction in barriers, encouragement by physicians needed
Quality assurance is needed for colonoscopy and CT colonography
Resource may be a limitation
Stratification or mixed strategies may be more cost-effective
Pilot studies in screening general population likely to be needed- up-take/ capacity/ cost-effectiveness for each country
Bangk
ok, Thaila
nd
CanalAVIST Medical Forum
19 September 2008
End of Presentation
by
Dr Taya Kitiyakara