The Costs and Benefits of Risk Stratification for Colorectal Cancer Screening Based On Phenotypic and Genetic Risk: A Health Economic Analysis.

Simon Griffin,Chloe Thomas,Juliet A Usher-Smith,Deborah Thompson,Olena Mandrik,Catherine L Saunders,Sophie Whyte

doi:10.1158/1940-6207.capr-20-0620

Abstract

Population-based screening for colorectal cancer is an effective and cost-effective way of reducing colorectal cancer incidence and mortality. Many genetic and phenotypic risk factors for colorectal cancer have been identified, leading to development of colorectal cancer risk scores with varying discrimination. However, these are not currently used by population screening programs. We performed an economic analysis to assess the cost-effectiveness, clinical outcomes, and resource impact of using risk-stratification based on phenotypic and genetic risk, taking a UK National Health Service perspective. Biennial fecal immunochemical test (FIT), starting at an age determined through risk-assessment at age 40, was compared with FIT screening starting at a fixed age for all individuals. Compared with inviting everyone from age 60, using a risk score with area under the receiver operating characteristic curve of 0.721 to determine FIT screening start age, produces 418 QALYs, costs £247,000, and results in 218 fewer colorectal cancer cases and 156 fewer colorectal cancer deaths per 100,000 people, with similar FIT screening invites. There is 96% probability that risk-stratification is cost-effective, with net monetary benefit (based on £20,000 per QALY threshold) estimated at £8.1 million per 100,000 people. The maximum that could be spent on risk-assessment and still be cost-effective is £114 per person. Lower benefits are produced with lower discrimination risk scores, lower mean screening start age, or higher FIT thresholds. Risk-stratified screening benefits men more than women. Using risk to determine FIT screening start age could improve the clinical outcomes and cost effectiveness of colorectal cancer screening without using significant additional screening resources. PREVENTION RELEVANCE: Colorectal cancer screening is essential for early detection and prevention of colorectal cancer, but implementation is often limited by resource constraints. This work shows that risk-stratification using genetic and phenotypic risk could improve the effectiveness and cost-effectiveness of screening programs, without using substantially more screening resources than are currently available.

Highlights

Colorectal cancer is the third most common diagnosed cancer in the world, accounting for 1.8 million new cases and 0.8 million deaths in 2018 [1]
Cost-effectiveness outcomes Risk-stratification based on a mean FIT at a threshold of 120 mg/g (FIT120) screening start age of 60 is expected to be cost-effective compared with starting FIT120 screening in all individuals at age 60, with incremental net monetary benefit per person ranging between £4 using the Ma score and £81 using the Total Risk þ Sex score (Fig. 1; Table 2), assuming a willingness-to–pay threshold of £20,000 per quality adjusted life year (QALY)
This difference in cost-effectiveness between risk scores is due to differences in QALY gain, as the higher discrimination risk scores result in higher total costs, with some of the lower discrimination scores being costsaving

Summary

Introduction

Colorectal cancer (colorectal cancer) is the third most common diagnosed cancer in the world, accounting for 1.8 million new cases and 0.8 million deaths in 2018 [1]. Screening is an effective way of reducing both mortality and incidence, by. Note: Supplementary data for this article are available at Cancer Prevention Research Online (http://cancerprevres.aacrjournals.org/). Many high-income countries have chosen to screen their populations using the biennial fecal immunochemical test The age at which FIT screening starts varies between countries with many starting at age 50 In England, FIT screening currently starts at age 60, despite studies indicating that reducing the start age to 50 would be highly cost-effective [3]. While the intention is to reduce screening start age to 50 eventually, resource constraints mean that there is currently insufficient capacity (at the point of follow-up colonoscopy) to do this [4]

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