Differential impact of test performance characteristics on burden-to-benefit tradeoffs for blood-based colorectal cancer screening: A microsimulation analysis

OBJECTIVES

To inform the development and evaluation of new blood-based colorectal cancer (CRC) screening tests satisfying minimum United States (US) coverage criteria, we estimated the impact of the different test performance characteristics on long-term testing benefits and burdens.

METHODS

A novel CRC-Microsimulation of Adenoma Progression and Screening (CRC-MAPS) model was developed, validated, then used to assess different screening tests for CRC. We compared multiple, hypothetical blood-based CRC screening tests satisfying minimum coverage criteria of 74% CRC sensitivity and 90% specificity, to measure how changes in a test's CRC sensitivity, specificity, and adenoma sensitivity (sizes 1-5 mm, 6-9 mm, ≥10 mm) affect total number of colonoscopies (COL), CRC incidence reduction (IR), CRC mortality reduction (MR), and burden-to-benefit ratios (incremental COLs per percentage-point increase in IR or MR).

RESULTS

A blood test meeting minimum US coverage criteria for performance characteristics resulted in 1576 lifetime COLs per 1000 individuals, 46.7% IR and 59.2% MR compared to no screening. Tests with increased CRC sensitivity of 99% ( + 25%) vs. increased ≥10 mm adenoma sensitivity of 13.6% ( + 3.6%) both yielded the same MR, 62.7%. Test benefits improved the most with increases in all-size adenoma sensitivity, then size-specific adenoma sensitivities, then specificity and CRC sensitivity, while increases in specificity or ≥10 mm adenoma sensitivity resulted in the most favorable burden-to-benefit tradeoffs (ratios <11.5).

CONCLUSIONS

Burden-to-benefit ratios for blood-based CRC screening tests differ by performance characteristic, with the most favorable tradeoffs resulting from improvements in specificity and ≥10 mm adenoma sensitivity.

Detecting salivary host and microbiome RNA signature for aiding diagnosis of oral and throat cancer

OBJECTIVE

Oral squamous cell carcinoma (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC) can go undetected resulting in late detection and poor outcomes. We describe the development and validation of CancerDetect for Oral & Throat cancer™ (CDOT), to detect markers of OSCC and/or OPSCC within a high-risk population.

MATERIAL AND METHODS

We collected saliva samples from 1,175 individuals who were 50 years or older, or adults with a tobacco use history. 945 of those were used to train a classifier using machine learning methods, resulting in a salivary microbial and human metatranscriptomic signature. The classifier was then independently validated on the 230 remaining samples prospectively collected and unseen by the classifier, consisting of 20 OSCC (all stages), 76 OPSCC (all stages), and 134 negatives (including 14 pre-malignant).

RESULTS

On the validation cohort, the specificity of the CDOT test was 94 %, sensitivity was 90 % for participants with OSCC, and 84.2 % for participants with OPSCC. Similar classification results were observed among people in early stage (stages I & II) vs late stage (stages III & IV).

CONCLUSIONS

CDOT is a non-invasive test that can be easily administered in dentist offices, primary care centres and specialised cancer clinics for early detection of OPSCC and OSCC. This test, having received FDA's breakthrough designation for accelerated review, has the potential to enable early diagnosis, saving lives and significantly reducing healthcare expenditure.

Abstract 2240: Interception versus prevention in cancer screening: Results from the CRC-MAPS model

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.

Interception versus prevention in cancer screening in a Medicare population: Results from the CRC-MAPS model

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Background: This study examines the impact of detecting cancer (interception) versus adenomas and cancer (prevention + interception) on clinical outcomes in a screen-naive Medicare cohort for a hypothetical colorectal cancer (CRC) screening test or a 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 65 to 75. CRC IR and MR outcomes compared to no screening were aggregated from age 65 until death. Threshold analysis (#5) identified the ≥10mm adenoma sensitivity needed for a base-case cancer interception test (#1) to yield CRC MR equivalent to a near-perfect cancer interception test (#2). Results: The base-case interception scenario (#1) resulted in 5.6% CRC IR and 21.7% MR compared to 5.2% CRC IR and 25.9% MR for the near-perfect interception scenario (#2). The threshold analysis demonstrates that when the base-case interception scenario's ≥10mm adenoma sensitivity is increased from 1% to just 2.43% (#5), the resulting MR is equivalent to a near-perfect interception test. Accordingly, the cancer prevention + interception scenarios (#3, #4) resulted in CRC IR and MR outcomes 9.7-12.9x and 2.5-3.4x (respectively) as favorable as either cancer interception scenario due to adenoma detection. 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 explore both benefits and burdens of different screening tests. Moreover, this approach will be applied to better understand the clinical utility of MCED tests. [Table: see text]

Estimating the impact of differential adherence on the comparative effectiveness of stool-based colorectal cancer screening using the CRC-AIM microsimulation model

BACKGROUND

Real-world adherence to colorectal cancer (CRC) screening strategies is imperfect. The CRC-AIM microsimulation model was used to estimate the impact of imperfect adherence on the relative benefits and burdens of guideline-endorsed, stool-based screening strategies.

METHODS

Predicted outcomes of multi-target stool DNA (mt-sDNA), fecal immunochemical tests (FIT), and high-sensitivity guaiac-based fecal occult blood tests (HSgFOBT) were simulated for 40-year-olds free of diagnosed CRC. For robustness, imperfect adherence was incorporated in multiple ways and with extensive sensitivity analysis. Analysis 1 assumed adherence from 0%-100%, in 10% increments. Analysis 2 longitudinally applied real-world first-round differential adherence rates (base-case imperfect rates = 40% annual FIT vs 34% annual HSgFOBT vs 70% triennial mt-sDNA). Analysis 3 randomly assigned individuals to receive 1, 5, or 9 lifetime (9 = 100% adherence) mt-sDNA tests and 1, 5, or 9 to 26 (26 = 100% adherence) FIT tests. Outcomes are reported per 1000 individuals compared with no screening.

RESULTS

Each screening strategy decreased CRC incidence and mortality versus no screening. In individuals screened between ages 50-75 and adherence ranging from 10%a-100%, the life-years gained (LYG) for triennial mt-sDNA ranged from 133.1-300.0, for annual FIT from 96.3-318.1, and for annual HSgFOBT from 99.8-320.6. At base-case imperfect adherence rates, mt-sDNA resulted in 19.1% more LYG versus FIT, 25.4% more LYG versus HSgFOBT, and generally had preferable efficiency ratios while offering the most LYG. Completion of at least 21 FIT tests is needed to reach approximately the same LYG achieved with 9 mt-sDNA tests.

CONCLUSIONS

Adherence assumptions affect the conclusions of CRC screening microsimulations that are used to inform CRC screening guidelines. LYG from FIT and HSgFOBT are more sensitive to changes in adherence assumptions than mt-sDNA because they require more tests be completed for equivalent benefit. At imperfect adherence rates, mt-sDNA provides more LYG than FIT or HSgFOBT at an acceptable tradeoff in screening burden.

Evaluation of the Economic Benefit of Earlier Systemic Lupus Erythematosus (SLE) Diagnosis Using a Multivariate Assay Panel (MAP)

Objective

Diagnosis of systemic lupus erythematosus (SLE) made by standard diagnostic laboratory tests (SDLTs) has sensitivity and specificity of 83% and 76%, respectively. A multivariate assay panel (MAP) combining complement C4d activation products on erythrocytes and B cells with SDLTs yields a sensitivity and specificity of 80% and 86%, respectively, presumably enabling earlier SLE diagnosis at lower severity, with associated lower health care costs compared with SDLT diagnoses. We compared the payer budget impact of diagnosing SLE using MAP (incremental cost of $108) versus SDLTs.

Methods

We modeled a health plan of 1 million enrollees. SLE diagnosis among suspected patients was 9.2%. The MAP arm assumed 80%/20% of patients were tested with MAP/SDLTs, versus 100% tested with SDLTs in the SDLT arm. Prediagnosis direct costs were estimated from claims data, and postdiagnosis costs were obtained from the literature. Based on improved MAP performance, the assumed hazard ratio for diagnosis rate compared with SDLTs was 1.74 (71%, 87%, 90%, and 91% of patients who develop SLE are diagnosed in years 1 to 4 compared with 53%, 75%, 84%, and 88% of patients diagnosed with SDLTs).

Results

Total 4‐year pre‐ and postdiagnosis direct costs for patients with suspected SLE tested with MAP were $59 183 666 compared with $61 174 818 tested by SDLTs, with lower costs in the MAP arm due primarily to prediagnosis savings related to reduced hospital admissions.

Conclusion

Incorporating MAP into SLE diagnosis results in estimated 4‐year direct cost savings of $1 991 152 ($0.04 per member per month). By facilitating earlier diagnosis of SLE, MAP may enhance patient outcomes.

Estimating the Screening-Eligible Population Size, Ages 45-74, at Average Risk to Develop Colorectal Cancer in the United States

Colorectal cancer is a growing burden in adults less than 50 years old. In 2018, the American Cancer Society published a guideline update recommending a reduction in the colorectal cancer screening start age for average-risk individuals from 50 to 45. Implementing these recommendations would have important implications for public health. However, the approximate number of people impacted by this change, the average-risk population ages 45-49, is not well-described in the literature. Here, we provide methodology to conservatively estimate the average-risk and screening-eligible population in the United States, including those who would be impacted by a lowered colorectal cancer screening start age. Using multiple data sources, we estimated the current average-risk population by subtracting individuals with symptomatic colorectal cancer, with a family history of colorectal cancer, and with inflammatory bowel disease and hereditary nonpolyposis colorectal cancer from the total population. Within this population, we estimated the number of screening-eligible individuals by subtracting those with previous colorectal cancer screening (45- to 49-year-old) or up to date with colorectal cancer screening (50- to 74-year-old). The total average-risk population is estimated between 102.1 and 106.5 million people, of whom 43.4-45.2 million people are eligible for colorectal cancer screening. Lowering the screening age would add roughly 19 million people to the average-risk population and increase the current number of screening-eligible individuals on immediate implementation by over 60% (from 27 to 44 million). Estimating the population size impacted by lowering the recommended colorectal cancer screening start age enables more accurate decision-making for policymakers and epidemiologists focused on cancer prevention.