Abstract 2240: Interception versus prevention in cancer screening: Results from the CRC-MAPS model
Authors: Putcha Girish , Carroll Lauren N. , Fransen Signe , Chandra Tarun , Piscitello Andrew 
Published: June 2022

Abstract
Purpose: This study examines the impact of detecting cancer (interception) versus adenomas and cancer (prevention + interception) on clinical outcomes for a hypothetical colorectal cancer (CRC) screening test or multicancer early detection (MCED) test that includes CRC.
Methods: CRC-MAPS™, a validated microsimulation model of the adenoma-carcinoma pathway that reproduced incidence reduction (IR) and mortality reduction (MR) consistent with CISNET models and a randomized controlled trial, was used to simulate perfect adherence to a hypothetical annual screening test among previously unscreened individuals free of diagnosed CRC. Four scenarios were examined: two cancer interception and two cancer prevention + interception. Individuals were screened from age 45 to 75. CRC IR and MR outcomes compared to no screening were aggregated from age 40 until death. Threshold analysis identified the ≥10mm adenoma sensitivity needed for a base case cancer interception test to yield CRC MR equivalent to a near-perfect cancer interception test (#2).
Results: The base case scenario (#1) resulted in 15.0% CRC IR and 34.2% MR compared to 14.7% CRC IR and 38.3% MR for the near-perfect interception scenario (#2). In the threshold analysis, a modified base case cancer interception test (#5) yielded MR equivalent to a near-perfect interception test (#2) when ≥10mm adenoma sensitivity was increased from 1% to 1.94%. Due to adenoma detection, the cancer prevention + interception scenarios (#3, #4) resulted in outcomes more than twice as favorable as either cancer interception scenario.
Conclusions: This analysis highlights that even small improvements in the detection of precancerous lesions for certain cancers (e.g., adenomas for CRC), which enable cancer prevention, can yield clinical benefits that meaningfully exceed those from tests that primarily detect cancer. Future studies will apply this approach to other cancers, such as ovarian and breast, to better understand the clinical utility of MCED tests.
Table. Clinical outcomes for cancer interception and cancer prevention + interception scenarios Scenario Specificity Adenoma Sensitivity CRC Sensitivity CRC IR CRC MR 1. Cancer Interception (base case) 99% 1-5mm: 1% 6-9mm: 1% ≥10mm: 1% 60% 15.0% 34.2% 2. Cancer Interception (near-perfect) 99% 1-5mm: 1% 6-9mm: 1% ≥10mm: 1% 99% 14.7% 38.3% 3. Cancer Prevention (with FIT-like adenoma sensitivity) + Interception 99% 1-5mm: 5% 6-9mm: 10% ≥10mm: 20% 60% 73.5% 79.1% 4. Cancer Prevention (with improved FIT-like adenoma sensitivity) + Interception 99% 1-5mm:10% 6-9mm: 20% ≥10mm: 30% 60% 82.8% 86.2% 5. Threshold analysis 99% 1-5mm: 1% 6-9mm: 1% ≥10mm: 1.94% 60% 20.3% 38.3%
Citation Format: Girish Putcha, Lauren N. Carroll, Signe Fransen, Tarun Chandra, Andrew Piscitello. Interception versus prevention in cancer screening: Results from the CRC-MAPS model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2240.