Cost-effectiveness of adenoma surveillance - the Dutch guidelines -

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1 Cost-effectiveness of adenoma surveillance - the Dutch guidelines - WEO working group adenoma surveillance 20 May, 2016 Iris Lansdorp-Vogelaar, PhD On behalf of the SAP study-group

2 Introduction Adenoma patients increased risk to develop colorectal cancer (CRC) compared to the average population, even after polypectomy regular surveillance colonoscopy recommended Adenoma removal and subsequent surveillance can reduce CRC incidence by 76-90% Not all adenoma patients at equal risk: several factors for higher risk of metachronous advanced neoplasia identified

3 Dutch surveillance guidelines Dutch surveillance guidelines solely based on number of adenomas Since adenomas surveillance after 3 years 1 or 2 adenomas surveillance after 6 years Insufficient adherence to 2002 guidelines Limited colonoscopy resources

4 International surveillance guidelines Mostly based on adenoma number and characteristics However risk predictors not considered simultanuously, but rather dichotomous Studies show each risk factor constitutes additional risk of advanced neoplasia independent of other risk factors Dutch Surveillance After Polypectomy (SAP) study: can efficiency of surveillance be improved? 4

5 SAP-study: Aims 1. How well does the risk profile of a patient, based on adenoma findings and patient characteristics at initial colonoscopy, predict his risk of future adenomas? 2. What are cost-effective surveillance strategies after polypectomy for patients with different risk profiles, using the results from research question 1?

6 SAP-study: Data collection 10 hospitals throughout the Netherlands Identification of newly diagnosed adenoma patients by PALGA ( ) Electronic medical records (endoscopy and pathology reports) until December 2008 Exclusion criteria: age <40 years, CRC history, hereditary CRC syndromes, IBD, prior colonic resection, no surveillance

7 SAP-study: Data collected Patient characteristics Age (date of birth) Gender Adenoma characteristics: findings at index and surveillance colonoscopy Number of adenoma Histology: degree of dysplasia, villousness Adenoma localization Adenoma size Colonoscopy characteristics (quality indicators) Date colonoscopy Bowel preparation Colonoscopy reach

8 Methods SAP-study Step I: Predictors of metachronous (advanced) colorectal neoplasia multinomial logistic regression analysis Step II: Risk stratification (risk profiles) score chart Step III: Optimal surveillance intervals Cost-effectiveness analysis with MISCAN micro-simulation model

9 SAP-study: population characteristics 2,990 adenoma patients with at least 1 surveillance endoscopy 55% male mean ±SD age: 61 ±10 years Findings at surveillance No. of patients Median surveillance interval (years) No adenomas 1,833 (61%) 4 Non-advanced adenoma(s) 954 (32%) 3 Advanced adenomas or CRC 203 (7%) 3

10 SAP-study step I: Predictors of advanced colorectal adenoma N = 2,990 with at least 1 surveillance endoscopy Predictors Patient characteristics Male gender Age (per 10 yr increase) Baseline adenoma characteristics Adenoma number Size 10 mm High grade dysplasia Villous ( 75%) histology Proximal location Van Heijningen, Gastroenterology 2013 AA* (OR 95% CI) SAP-study 1.6 ( ) 1.3 ( ) 1.0 (ref) 1.6 ( ) 2.1 ( ) 2.0 ( ) 3.3 ( ) 1.7 ( ) 1.2 ( ) 2.0 ( ) 1.6 ( )

11 Predictors SAP-study vs. Martinez et al. Predictors Patient characteristics Male gender Age (per 10 yr increase) Baseline adenoma characteristics Adenoma number AA* (OR 95% CI) SAP-study 1.6 ( ) 1.3 ( ) 1.0 (ref) 1.6 ( ) 2.1 ( ) 2.0 ( ) 3.3 ( ) AA (OR 95% CI), Martinez 1.4 ( ) 1.0 (ref 50-59) 1.4 ( ) 1.0 (ref) 1.4 ( ) 1.9 ( ) 2.4 ( ) 3.9 ( ) Size 10 mm High grade dysplasia Villous ( 75%) histology Proximal location * AA= Advanced adenoma (size 10mm, HGD, villous, CRC) Martinez, Gastroenterology ( ) 1.2 ( ) 2.0 ( ) 1.6 ( ) 1.6 ( ) 1.1 ( ) 1.4 ( ) 1.7 ( )

12 Predictors SAP-study vs. De Jonge et al. Predictors Patient characteristics Male gender Age (per 10 yr increase/ <60 vs > 60) Baseline adenoma characteristics Adenoma number AA* (OR 95% CI) SAP-study 1.6 ( ) 1.3 ( ) 1.0 (ref) 1.6 ( ) 2.1 ( ) 2.0 ( ) 3.3 ( ) Any Adenoma (OR 95% CI), De Jonge 1.2 ( ) 1.7 ( ) 1.0 (ref) 1.6 ( ) 1-2 vs. 3+ Size 10 mm High grade dysplasia Villous ( 75%) histology Proximal location * AA= Advanced adenoma (size 10mm, HGD, villous, CRC) De Jonge, Endoscopy ( ) 1.2 ( ) 2.0 ( ) 1.6 ( ) 1.7 ( ) 1.7 ( ) 1.2 ( ) 1.4 ( ) Tub.Vill

13 Step II: translation into risk stratification Development score chart based on adenoma characteristics alone Points allocated to each adenoma characteristic in proportion to their absolute risks (LN (OR)) Age, gender and life expectancy not included in score chart, because these impact benefit of surveillance in two ways: CRC risk and life-years to be gained per CRC death prevented

14 Score chart based on adenoma characteristics Adenoma characteristics Value Score Number of adenoma 1 0 Presence of at least 1 adenoma 10mm Presence of at least 1 villous adenoma * Presence of at least 1 proximal adenoma Total score * 75% villous No Yes No Yes No Yes Score range: 0-5 (6 risk groups) Van Heijningen, Gut 2015

15 Odds ratio Relative risk per total adenoma risk score 25 24, ,2 10, ,5 3, Total adenoma risk score

16 STEP III: Optimal surveillance intervals Surveillance strategies Population simulated: score, age & gender MISCAN model Costs and QALY Incremental costeffectiveness analysis

17 Population simulated Ninety cohorts: Age: 40, 45,, 75, 80 Gender: men, women Adenoma risk score: Cohorts differed with respect to CRC risk (based on results step I) and life-expectancy (based on Dutch life tables)

18 Surveillance strategies simulated Eleven surveillance strategies: No surveillance Surveillance interval: years

19 Effects of 3-yearly surveillance in women age Score: QALY (3% discounted)

20 Costs of 3-yearly surveillance in women age Score: Costs (3% discounted)

21 QALY Costs and effects of surveillance in women age 60 with adenoma risk score 0 (3% discounted) [CELLRANGE] [CELLRANGE] [CELLRANGE] [CELLRANGE] 4,357/QALY [CELLRANGE] 46,488/QALY Costs (Thousands)

22 Recommended surveillance-interval according to adenoma risk score, age, and gender Adenoma risk score Female Male Age to stop surveillance < 55 years 55 years < 55 years 55 years 0 NS* NS* NS* NS* Score 0: Pt with 1 small distal tubular/tubulovillous adenoma NS* = no surveillance, return to CRC screening after 10 years

23 SAP-study: Conclusions The risk of recurrent advanced neoplasia depends on older age, male gender, adenoma number, size 10 mm, villous histology, and proximal location The observed relative risks allow for risk stratification and targeted surveillance The surveillance interval should depend on adenoma score (score chart), age, and gender Shorter interval when Higher adenoma risk score Men compared to women Older age

24 Dutch surveillance guideline workgroup Reviewed the literature / evidence, including findings SAP study Guideline based on SAP-study Independent predictors confirmed by the literature Includes cost-effectiveness analysis Decided to simplify the proposed SAP-guideline Age and gender eliminated (CRC screening 55 years) Some adenoma risk scores combined Same stop age of 75 years for all adenoma patients, considering health status

25 New surveillance guideline (2013) 1: Determine patients adenoma score 2: Look up recommended interval Adenoma characteristics Value Score Number of adenoma Adenoma risk score Interval 0 NS*/5 Age to stop surveillance Presence of at least 1 adenoma 10mm Presence of at least 1 villous adenoma * Presence of at least 1 proximal adenoma No Yes No Yes No Yes NS* = no surveillance, return to CRC screening after 10 years, if age allows (<75years) This is age at adenoma detection. The ending age holds for subjects with an average life expectancy, decisions should also depend on co-morbidity and vitality of the subjects Total score * 75% villous

26 Thank you

27 Acknowledgement Gastroenterology and pathology departments Academic Medical Center, Amsterdam Albert Schweitzer Hospital, Dordrecht Deventer Hospital, Deventer Erasmus MC, University Medical Center, Rotterdam Isala Clinics, Zwolle Medical Center Leeuwarden, Leeuwarden Orbis Medical Center, Sittard Reinier de Graaf Hospital, Delft St. Antonius Hospital, Nieuwegein University Medical Center Groningen, Groningen Dutch colonoscopy surveillance guideline committee Evelien Dekker, Monique van Leerdam, Annemarie van Berkel, Silvia Sandaleanu, Iris Nagtegaal, Hans Vasen