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Colorectal Cancer Screening and Surveillance FDA Advisory Committee March, 2002 David Lieberman MD Chief, Division of Gastroenterology Oregon Health Sciences University Preventing Cancer Normal Colon Advanced Adenoma Cancer Colon Cancer Prevention MD Colon Cancer Detection
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Colorectal Cancer Screening and Surveillance FDA Advisory Committee March, 2002 David Lieberman MD Chief, Division of Gastroenterology Oregon Health Sciences University
Preventing Cancer Normal Colon Advanced Adenoma Cancer
Colon Cancer Prevention MD Colon Cancer Detection Raising the bar
Colorectal Cancer ScreeningRecommendations • FOBT annual • Sigmoidoscopy every 5 yrs • FOBT + Sigmoidoscopy • Barium Enema every 5-10 yrs • Colonoscopy every 10 yrs U.S. Preventive Services,1995 AHCPR Multi-discipline Panel, 1997 Am College Gastro “Preferred option”, 2000 Am. Cancer Society,2001
Fecal Occult Blood Test • RCT demonstrate mortality reduction (15-33%) • Easy to perform • Can be completed by primary providers
Detection of Advanced Neoplasia with one-time test: 24% Fecal Occult Blood Test • Poor sensitivity for one-time test • Requires repeat testing • Compliance with repeat testing poor • Costs are deceptive
Sigmoidoscopy Evidence: Case-Control Studies: 60% reduction in CRC mortality in the examined portion of the colon
Sigmoidoscopy Advantages: - Detects early cancer or polyps - Can be performed by primary care providers Limitations: - Examines 1/3 of colon - Proximal lesions may not be detected
A NEJM 2001; 345:555-60 Detection of Advanced Neoplasia: VA Study Data Sigmoidoscopy alone: Detection: 70% FOBT alone: Detection: 24% FOBT + Sigmoidoscopy: Detection: 76%
Barium Enema • No Data in screening populations • Miss rate for polyps > 1cm exceeds 50%(National Polyp Study)
Attractive name Sensitivity for largepolyps Rapid exam Cost-effectiveness uncertain False positive rate increases cost Some patient discomfort Small polyp dilemma Virtual Colon Imaging Limitations Advantages
Screening with Colonoscopy • Limitations • Risk • Costs • Resources • Advantages • Detection of early cancer and advanced adenomas • Indirect evidence for effectiveness
NEJM 2000;343;162-8 & 169-174 Screening with Colonoscopy Lieberman Imperiale n = 3121 n = 1994 Age 62.9 yrs 58.9 yrs % male 96.8% 58.9% % of exams complete 97.0% 97.0% % with Advanced Neoplasia 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 With increasing age: • prevalence of advanced neoplasia increases • prevalence of proximal 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.
Colonoscopy Colon Screening FOBT Sigmoidoscopy Colon Imaging Fecal markers Colonoscopy Surveillance Colonoscopy
Screening Issues • Surveillance • Risk • Cost • Resources
FINDING INTERVAL Adenoma >1cm 3 yrs Multiple adenomas 3 yrs 1-2 tub. Adenoma < 1cm 3-5 yrs Colon Surveillance:Recommendations Surveillance accounts for 20-50% of cost of colon screening programs
N Engl J Med 2000; 343: 162 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 ADVANCED 10.6% Among patients with neoplasia, 72% had only Tub. Adenomas < 1cm
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
Gastrointest Endosc 2002; 55: 307-14 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: VA Coop Study Risk of Screening Colonoscopy Major Complications (Definite) GI bleed + hosp. or transfusion 7 (6) 0.22% Perforation 0 New 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 ?
Cost of not screening Cost of Cancer Care Emotional Costs Missed opportunity for prevention
Cost of Colon Cancer Screening Cost ($) per added year of life (x 1000) Colon Hypertension Mammography Cholesterol Screening
Resources: Supply and Demand Capacity Colon New Demand Screening
CORI: National Endoscopic Database 2000-2001 Colonoscopy: Indications Current Screening BRBPR Pain Polyp-Surv +FOBT Diarrhea Screen Cancer Surv Constip. +FHx Anemia FS/BaE IBD
N Engl J Med 2000; 343:162-8: VA Coop Shifting Resources: Surveillance 72% of asymp. men with neoplasia had only small tubular adenomas Can we shift resources from surveillance to screening ? Low Risk of Cancer
Supply and Demand Demand Capacity New Demand Increased capacity: - shift resources - improve efficiency
Summary of Screening Guidelines Potential Strategy Evidence Mortality Limitations 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 (+) rates Imaging - Poor sensitivity Colonoscopy Indirect 70-80% - Invasive, higher risk
Chemo- Prevention Adenoma Possible role of chemo-prevention Intervention Recurrence Surveillance Recurrence Cancer Advanced Adenoma
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