Colorectal Cancer Screening: Cost-Effectiveness and Adverse events October, 2005

Transcription

1 Colorectal Cancer Screening: Cost-Effectiveness and Adverse events October, 2005 David Lieberman MD Chief, Division of Gastroenterology Oregon Health and Science University Portland VAMC

2 Portland, Oregon

3 Colon Cancer 1 million new cases/year 530,000 deaths/year 2 nd leading cause of cancer death in North America and Western Europe

4 Colorectal Cancer Genetic Environmental Lifestyle Normal Colon National Polyp Study: 76-90% reduction in Cancer incidence after polypectomy Advanced Adenoma 10-20% Lifetime Risk 5-6% Lifetime Risk

5 Raising the bar Colon Cancer Detection Colon Cancer Prevention MD

6 Risk Factors for CRC Family History 15-20% HNPCC 3-5% FAP-1% IBD-1% Sporadic/ Average Risk 75%

7 Colorectal Cancer Screening USA Recommendations FOBT annual Sigmoidoscopy every 5 yrs FOBT + Sigmoidoscopy Barium Enema every 5-10 yrs Colonoscopy every 10 yrs GI Multi-Society Task Force, 1997, 2003 American College of Gastroenterology, 2000 American Cancer Society, 2003 US Preventive Services Task Force, 2002

8 Topic: Cost and Adverse Events Program Costs: Initial test Evaluation of (+) test Follow-up of (-) test Surveillance of patients with neoplasia Cost of cancer care Cost of complications Adverse events in program Serious complications leading to: Hospitalization Blood transfusion Surgery Death Missed lesions False reassurance

9 Fecal Occult Blood Test (FOBT) Mortality Trial Frequency Reduction Adherent Minnesota: Annual 33% Notingham: Biennial 15% 39% Denmark: Biennial 18% 33% France (2004) Biennial* 16% 33% Reduction in incidence: 17-20% NEJM 2000; 343:1603-7

10 Lieberman et al;nejm 2001;345: Imperiale et al; NEJM 2004;351: Collins, Lieberman et al; Ann Intern Med 2005; 142:81-5 FOBT - Limitations One-time test ineffective Sensitivity for advanced neoplasia: 11-24% Digital FOBT inadequate but often used Sensitivity for advanced neoplasia: 4.9% Complex program: need adherence at every level of test FOBT

11 FOBT Complex Program Step 1: Adherence with initial test Step 2a: If test NEGATIVE: adherence with repeat testing at 1-2 years Step 2b: If test POSITIVE: adherence with colonoscopy FOBT

12 Program Elements - Hidden Costs Initial Test $ Evaluation of (+) test with Colonoscopy $$$ (2-4% with one test) Repeat test every 1-2 years reminders $$$ Cumulative rate of (+) tests over yrs with colonoscopy evaluation $$$ (? 25-30% of asymp. pop) Missed/detected cancers cost of cancer care $$$ Surveillance colonoscopy All patients with adenomas or cancer $$$ FOBT

13 FOBT: Mortality Reduction Adherence at Every level: 100% Potential Mortality Reduction 40% IF adherence to initial test 75%; All else 100% 30% IF Follow-up of (+) test 75% 23% FOBT IF Follow-up of (-)) test 50% 12%

14 FOBT Summary Effective but only in a program of repeat testing Cost cost-effectiveness of program similar to other screening tests Adverse events: Missed cancers False reassurance FOBT

15 Lieberman et al; NEJM 2000; 343: 162-8; Schoenfeld et al; NEJM 2005; 352: Sigmoidoscopy- U.S. Studies Sensitivity* for Advanced Neoplasia: 70% in men 35% in women More than 50% Not detected Less effective with increasing age

16 Ahlquist et al; Gastroenterol 2000; 119: Stool Genetic Tests CA >1cm Sensitivity Specificity Mutations: K-ras, p53, APC Microsatellite instability marker (Bat-26) Long DNA

17 Imperiale et al; NEJM 2004;351: Stool Genetic Tests % DNA FOBT 0 Cancer n=31 Cancer + HGD n = 71 All Advanced n = 418

18 CT Colonography

19 CT Colonography

20 CT Colonography: Issues Sensitivity: Detection of patients with adenomas >9mm: Sensitivity Specificity Pickhardt 94% 96% Cotton 55% 96% Rockey 59% 96% NEJM 2003; 349: 2191; JAMA 2004; 291:1713-9; Rockey: Lancet 2005;365:

21 CT Colonography: Issues Bowel Prep Radiation Cost Threshold for (+) test Extracolonic findings

22 Pickhardt et al; NEJM 2003:349: CT Colonography: What is a positive test? > 9mm 5-10% >5mm 25-30% ALL 50%

23 Pickhardt et al; NEJM 2003:349: Pedersen et al; Gut 2003; 52: Extracolonic Findings Pickhardt: 4.5% ( high clinical import) Pedersen: (n = 75) 65% had extracolonic abnormalities 12%: additional work-up indicated Types of serious findings Ovarian CA - Hepatic lesions Renal cell CA - Adrenal lesions Lung tumors - Enlarged uterus

24 CT Colonography- Issues Cost key factors Threshold for (+) test and referral to colonoscopy: Evaluation of extra-colonic findings can be costly If a high proportion of patients are referred for Colonoscopy, CT will not be cost-effective

25 Average-Risk Screening: Colonoscopy Best test for polyp detection and cancer prevention Large upfront cost Not perfect!!! 2-12% of polyps > 1cm not found Requires highly qualified endoscopist

26 Miss-rate at colonoscopy per patient sensitivity of CSP Author n for adenoma >1cm Pickhardt (2003) % Cotton (2004) % Rockey (2005) % NEJM 2003; 349: 2191; JAMA 2004; 291:1713-9; Lancet 2005; 365:305-11

27 Gastrointest Endosc 2002; 55: : 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/ % For Diagnostic only 2/ % All complications %

28 Gastrointest Endosc 2002; 55: Risk of Screening Colonoscopy Death within 30d 3 (no apparent relationship) Minor Complications Vasovagal events % Transient O2 desaturation % Minor GI bleeding % Abdominal pain > 2 hrs % Abdominal pain causing procedure termination % Other %

29 Korman et al; Gastrointest Endosc 2003; 58: Risk of Colonoscopy Perforation risk in Ambulatory Surgical Centers 116,000 procedures in 45 centers in perforations ( 0.03%) 24 with diagnostic procedures Sigmoid most common site (62%)

30 Complications of Colonoscopy Risk of serious complications 2-3/1000 Incomplete exams Missed lesions Incompletely removed lesions Solution: Emphasis on Quality

31 All screening leads to FOBT Sigmoidoscopy Imaging ( CT) Genetic Primary Screening Colonoscopy Colonoscopy Surveillance colonoscopy after polyps are removed

32 Average-Risk Screening: Current status Mortality Cancer TEST Issues Reduction Prevention FOBT Needs annual test 30% + Complex program Poor one-time sensitivity Sigmoid Misses proximal 50-60% ++ lesions CT Variable Sensitivity?? 60% +++ Stool DNA Poor Sensitivity?? 30%? Colonoscopy High up-front cost?? 65-75% ++++ Risk uncertain Requires qualified endoscopist

33 Cost of not screening $50-80,000 per case Cost of Cancer Care Emotional Costs Missed opportunity for prevention

34 Institute of Medicine; 2005 Cost-Effectiveness (5 studies) Cost per year of life gained Low High FOBT: lowest Cost/yr of life gained FOBT FS FOBT/FS Radiol Colon Colonoscopy: highest rate of cancer prevention

35 Cost of Colon Cancer Screening 40 Cost ($) per added year of life (x 1000) Colon Hypertension Mammography Cholesterol Screening

36 Obstacles to Screening: Perceptions The most effective screening test is the test which patients will do!!

37 Summary Colon screening of asymptomatic populations is effective: Reduce mortality from CRC Reduce incidence of CRC Screening must be viewed as a program Each method has limitations Programmatic costs are similar Adverse events Complications due to risk of colonoscopy which is a part of every screening program We should consider missed lesions as adverse event

38 Screening can prevent Colon Cancer

39 Colon Cancer: per 100, Incidence and Mortality Male Female Incidence Mortality AGE

40 Institute of Medicine; 2005 Incremental Cost-Effectiveness FOBT/ FOBT FS FS X-ray Colon Harvard 18,347 WD 45,976 WD WD Ladabaum 9,631 SD SD 27,069 SD Miscan WD 8,230 8,848 SD SD Vanderbilt 8,409 SD SD 44,936 WD Vijan SD SD SD 3,980 38,854