colorectal cancer screening and surveillance fda advisory committee march, 2002 david lieberman md...
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Colorectal Cancer Screening Colorectal Cancer Screening and Surveillanceand Surveillance
FDA Advisory Committee FDA Advisory Committee March, 2002March, 2002
David Lieberman MDChief, Division of GastroenterologyOregon Health Sciences University
Preventing Cancer
Normal ColonNormal Colon Advanced Advanced AdenomaAdenoma
Raising the bar
MD
ColonColonCancerCancerDetectionDetection
Colon CancerColon Cancer PreventionPrevention
Colorectal Cancer ScreeningRecommendations
• FOBT annual• Sigmoidoscopy every 5 yrs• FOBT + Sigmoidoscopy• Barium Enema every 5-10 yrs• Colonoscopy every 10 yrs
U.S. PreventiveServices,1995
Am. CancerSociety,2001
AHCPR Multi-disciplinePanel, 1997
Am College Gastro“Preferred option”,
2000
Fecal Occult Blood Test
• RCT demonstrate mortality reduction (15-33%)
• Easy to perform
• Can be completed by primary providers
Fecal Occult Blood Test
• Poor sensitivity for one-time test
• Requires repeat testing
• Compliance with repeat testing poor
• Costs are deceptive
Detection of Advanced Neoplasiawith one-time test: 24%
Sigmoidoscopy
Evidence:Evidence:Case-Control Studies:60% reduction in CRC mortality in the examined portion of the colon
Sigmoidoscopy
Advantages:Advantages:- Detects early cancer or polyps- Can be performed by primary care providers
Limitations:Limitations:- Examines 1/3 of colon- Proximal lesions may not be detected
Detection of Advanced Neoplasia: VA Study Data
Sigmoidoscopy alone:Sigmoidoscopy alone:Detection: 70%
NEJM 2001; 345:555-60
FOBT alone:Detection: 24%
FOBT + Sigmoidoscopy:Detection: 76%
A
Barium Enema
• No Data in screening populations
• Miss rate for polyps > 1cm exceeds 50% (National Polyp Study)
Virtual CT
Virtual MR
Virtual Colon Imaging
• Attractive nameAttractive name• Sensitivity for large
polyps• Rapid exam
• Cost-effectiveness uncertain
• False positive rate increases cost
• Some patient discomfort
• Small polyp dilemmaSmall polyp dilemma
AdvantagesAdvantages LimitationsLimitations
Screening with Colonoscopy
AdvantagesAdvantages•Detection of early cancer and advanced adenomas•Indirect evidence for effectiveness
LimitationsLimitations• Risk• Costs• Resources
Screening with Colonoscopy
NEJM 2000;343;162-8 & 169-174
Lieberman Imperiale
n = 3121 n = 1994
Age 62.9 yrs 58.9 yrs
% male 96.8% 58.9%% of examscomplete 97.0% 97.0%% with AdvancedNeoplasia 10.6% 7.0%
Screening with Colonoscopy Evidence for Effectiveness
• National Polyp Study (1993):
• Selby et al (1992):
• Mandel et al (1993 and 2000):
- Polypectomy reduced cancer incidence
- Sigmoidoscopy reduced mortality…… in that portion of the colon examined
- FOBT screened patients had reduced mortality and incidence
Summary
• prevalence of advanced neoplasia increases
• prevalence of proximalproximal advanced neoplasia increases
• more patients with advanced neoplasia go undetected with FOBT and sigmoidoscopy
• colonoscopy may be more effective screening test in men after age 60 yrs.
With increasing age:With increasing age:
Colon Screening
FOBT
Sigmoidoscopy
Colon Imaging
Fecal markers
Colonoscopy
ColonoscopyColonoscopy
SurveillanceSurveillanceColonoscopyColonoscopy
Screening Issues
• Surveillance
• Risk
• Cost
• Resources
Colon Surveillance:Recommendations
FINDING INTERVAL
Adenoma >1cm 3 yrsMultiple adenomas 3 yrs1-2 tub. Adenoma < 1cm 3-5 yrs3-5 yrs
Surveillance accounts for 20-50% of cost of colon screening programs
Neoplasia in Asymptomatic Men
• Tubular adenoma <1cm 27.0
• Tubular adenoma >10mm 5.0
• Mixed/Villous 3.0
• High-grade dysplasia 1.6
• Invasive Cancer 1.0
Among patients with neoplasia, Among patients with neoplasia, 72% had only Tub. Adenomas < 1cm72% had only Tub. Adenomas < 1cm
%
N Engl J Med 2000; 343: 162
ADVANCEDADVANCED
10.6%10.6%
Surveillance
• Impact on cost of screening program
• Impact on available resources for screening
• Risk Management– Risk may be low for patients with small
adenomas– Could be reduced with chemoprevention
Risks of Screening Colonoscopy
• VA Cooperative Study:– n = 3196 exams
– mean age = 63.0 yrs
– Gender (% male) = 96.8
Gastrointest Endosc 2002; 55: 307-14
Risk of Screening Colonoscopy
Gastrointest Endosc 2002; 55: 307-14: VA Coop Study
Major Complications (Definite)Major Complications (Definite)GI bleed + hosp. or transfusion 7 (6) 0.22%Perforation 0New Atrial Fib 1 MI or CVA 4 (2) 0.12%Venous Thrombosis 1 (1)Other 4
ALL Definite 9/3196 0.3%
For Diagnostic only 2/1435 0.1%All complications 17 0.53%
Risk of Colonoscopy
• Significant Bleed – Prior studies 0.2-1.0%
– VA Coop 0.22 (all therapeutic)
• Perforation– Prior studies 0 - 0.2%
– VA Coop 0
Controlling Risk: - Training - Quality improvement
Colon Screening
Can we afford it ?Can we afford it ?
Cost of not screening
Cost of Cancer CareCost of Cancer CareEmotional CostsEmotional Costs
Missed opportunity for preventionMissed opportunity for prevention
Cost of Colon Cancer Screening
0
5
10
15
20
25
30
35
40
Cost ($)peraddedyear of life(x 1000)
Colon Hypertension Mammography CholesterolScreening
Resources: Supply and Demand
New Demand
Capacity
ScreeningColon
Colonoscopy: Indications
0
5
10
15
20
25
Polyp-Surv
+FOBT
BRBPR
Pain
Diarrhea
+FHx
ScreenScreen
Cancer Surv
Anemia FS/BaE IBD Constip.
CORI: National Endoscopic Database 2000-2001
Current Screening
Shifting Resources: Surveillance
N Engl J Med 2000; 343:162-8: VA Coop
72% of asymp. men with neoplasia had onlysmall tubular adenomas
Can we shiftresources fromsurveillance to
screening ?
Low Risk of Cancer
Supply and Demand
Demand Capacity
New Demand Increased capacity:- shift resources- improve efficiency
Summary of Screening GuidelinesPotentialPotential
StrategyStrategy EvidenceEvidence MortalityMortality LimitationsLimitations
FOBT RCT 20-50% - Need for repeat testing- Poor detection of advanced adenomas
Flexible Case- 50-55% - Miss-rate for Sigmoid (FS) Control proximal neoplasia
Barium/ none ?? 50-60% - False (+) ratesImaging - Poor sensitivity
Colonoscopy Indirect 70-80% - Invasive, higher risk
Intervention
Adenoma
Chemo-Prevention Surveillance
Advanced AdenomaCancer
Recurrence
Recurrence
Possible role ofchemo-prevention
Summary of Screening Guidelines
• Effectiveness of any screening program depends on patient compliance– In 1999, only 44% of adults aged 50 and older
had at least one recommended test at appropriate interval (MMWR, 2001)
• There are many obstacles to colon screening that reduce compliance
Challenges for the Future
• Identify risk factors for colorectal cancer– Stratify higher risk patients– Develop risk-reduction strategies
• Develop new tools to find high-risk patients– Genetic markers ( in blood or stool )– Circulating proteins– New imaging modalities
• Improve patient compliance
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