Limburg, Paul J.

Abstract The aim was to assess whether subject’s participation in early-phase chemoprevention trials was satisfactory and identify features associated with subjects’ satisfaction. Thirteen trials that investigated a range of candidate agents from 2006 to 2021 by the Cancer Prevention Network were included. The five-item “Was It Worth It?” (WIWI) questionnaire was administered to all subjects at the end of each trial’s intervention or at early termination. Satisfied overall was defined as a participant response of “yes” to the first three questions. Six hundred ninety-one participants from the United States, Canada, Puerto Rico, and Honduras enrolled on a trial. Six hundred fifty-two (94.4%) completed the WIWI questionnaire. Of these, 493 (75.6%) were White, non-Hispanic/Latino; 39 (6.0%) Black, non-Hispanic/Latino; 98 (15.0%) Hispanic/Latino; and 8 (1.2%) of another race/ethnicity. One hundred ninety-three were women (29.6%), 121 (17.5%) were ≥65 years, and 517 (79.3%) participated in a placebo-controlled trial. Eighty-five percent indicated being satisfied overall. Compared with White, non-Hispanic/Latino, the odds of not satisfied overall were 2.96 times higher for Black/Asian/>1 race, non-Hispanic/Latino (P < 0.001) and 0.40 times lower for Hispanic/Latino (P = 0.004). The odds of not satisfied overall was 1.9 times higher when the number of preintervention adverse events experienced was ≥1 (P = 0.012), 1.8 times higher when the percentage of the intervention duration with adverse events was >5% (P = 0.024), and 7.4 times higher for subjects who terminated the intervention early (P < 0.001). These findings can inform the design of future chemoprevention trials and help investigators improve accrual, retention, adherence, and diversity in this underexplored research setting. Prevention Relevance: The five-item “WIWI?” questionnaire, which captures the participant-reported experience of trial participation, gives the subject a voice in the development of new chemopreventative agents. This study in 652 subjects looked at satisfaction with participation in early-phase chemoprevention trials for higher-risk, cancer-free men and women. See related Spotlight, p. 7

Background Colorectal cancer (CRC) is the fourth most frequently diagnosed cancer and the second leading cause of cancer-related deaths in the United States. Screening can prevent CRC by detecting advanced precancerous lesions. Adherence to screening is crucial in reducing CRC disease burden; however, there is limited research on the impact of digital outreach screening uptake and adherence. Objective This study evaluated the impact of different digital outreach channels on patient adherence to CRC screening with a multi-target stool DNA (mt-sDNA) test in a real-world setting. Methods Patients were individuals aged 45 to 85 years with a valid mt-sDNA test order from Exact Sciences Laboratories, LLC (Jan. 1, 2023–Sept. 23, 2023). All patients received letters and phone calls; some received short message service (SMS), email, or both. Adherence and time to test return were compared across digital outreach categories stratified by patient characteristics. Multivariable regression evaluated the association of digital outreach methods with adherence and time to test return. Results Among 2 425 308 patients (43.5% between 50 and 64 years, 58.2% female), digital SMS only (62.7%) was the most common outreach method. Overall adherence was 70.1%, with highest adherence in the digital SMS-plus-email group (72.9%). Mean time to test return from shipment of mt-sDNA kit to receipt of valid test was 25.8 days. In adjusted analyses, patients receiving digital SMS plus email had the highest odds of test return (odds ratio, 1.75; 95% confidence interval [CI], 1.73-1.78; P <.001) and had return times 8.7% shorter than the no-digital-outreach group (95% CI, 8.2-9.2; P <.001). Discussion Among nationally insured individuals within the recommended age range for CRC screening, overall adherence to the mt-sDNA test was in the 70s, with the highest rates in the digital (SMS and email) outreach group and the lowest in the no-digital-outreach group. Conclusions These findings highlight the importance of multichannel navigation in facilitating completion of CRC screening with the mt-sDNA test.

Abstract The substantial carbon footprint imparted by medical services warrants increased attention to their environmental impact. National guideline organizations such as the US Preventive Services Task Force (USPSTF) recommend multiple modalities for average-risk colorectal cancer (CRC) screening with varying resource intensity. The aim of this study was to quantify the environmental burden for 2 of the most used CRC screening modalities, colonoscopy and the multi-target stool DNA (mt-sDNA) test. A validated CRC microsimulation model was used to estimate the number of screening and follow-up tests for a cohort of 1 million average-risk individuals who underwent screening between ages 45 and 75. Component resources used for mt-sDNA, including waste products, energy, and transportation for colonoscopy and mt-sDNA, were collected from January 1, 2023, to January 1, 2024, and converted to carbon-equivalent emissions. Resources used for colonoscopy were captured from the literature. Resources devoted to screening colonoscopy were substantially (59%) higher than those to mt-sDNA, even when including follow-up colonoscopy. Of note, follow-up colonoscopy accounted for the majority (64%) of total emissions for the mt-sDNA screening strategy. Compared with colonoscopy screening, mt-sDNA substantially reduces the carbon emissions attributable to population-level CRC screening. Environmental impact should be included as a factor when choosing among guideline-recommended CRC screening strategies.

89 Background: With estimates of over 150,000 incident and 50,000 fatal colorectal cancer (CRC) cases in 2024, efforts are ongoing to improve the national screening performance and engagement in the US. The Centers for Medicare & Medicaid Services (CMS) have established criteria for covering new blood-based CRC screening tests if minimum CRC sensitivity and specificity thresholds are met. However, the current blood-based tests are challenged by their relative inability to detect advanced precancerous lesions (APLs). At present, the importance of APL versus CRC sensitivity on screening outcomes remains undetermined. To address this knowledge gap, we conducted a simulation study to compare the screening effectiveness and outcomes of a hypothetical blood-based test across a range of sensitivities for CRC and APL detection. Methods: Outcomes were simulated using the CRC-AIM microsimulation model, which has been previously calibrated and validated. Predicted outcomes were calculated for average-risk individuals screened triennially with a blood-based test between ages 45-75 years, assuming perfect adherence. Base-case screening sensitivity and specificity inputs were based on CMS minimum thresholds (74% CRC sensitivity, 90% specificity) with assumed 10% APL sensitivity. Additional scenarios considered an increase in either APL or CRC sensitivity. Outcomes of interest included life years-gained (LYG), CRC incidence, and mortality reductions. Results: Compared to the CMS minimum performance (Table), increasing APL sensitivity by 1% (from 10% to 11%) resulted in a similar increase in LYG as compared to increasing CRC sensitivity by 11% (from 74% to 85%). Additionally, increasing APL sensitivity by 1% resulted in greater reductions in CRC cases and deaths (3% decrease) as compared to increasing CRC sensitivity by 11% (0% and 1% reductions, respectively). Conclusions: Data from this study show that increased APL sensitivity is a key determinant of screening-related outcomes, such as LYG, derived from a blood-based strategy, and that similar results would require much larger increases in CRC sensitivity. With the current CMS minimum performance threshold, blood-based tests that are designed to have high APL sensitivity can outperform tests with higher CRC sensitivity and little to no APL sensitivity. Comparison of CRC screening health outcomes with CMS proposed minimum threshold blood-test versus hypothetical tests with either increased APL and CRC sensitivity. APL Sensitivity CRC Sensitivity CRC Specificity Follow-up Colonoscopies CRC Cases (% reduction) CRC Deaths (% reduction) Life-Years Gained (LYG) (% increase) 10% 74% 90% 809 50 (ref) 18 (ref) 220 (ref) 11% 74% 90% 813 48 (-3%) 17 (-3%) 226 (3%) 10% 85% 90% 809 50 (0%) 18 (-1%) 227 (3%) APL: Advanced precancerous lesions; CRC: Colorectal cancer.

88 Background: There are an estimated 60 million individuals in the US who are not up-to-date with average-risk colorectal cancer (CRC) screening, as screening rates and adherence have remained stubbornly below the national target of 80%. Efforts are ongoing to improve CRC screening performance and participation, including the development of new blood-based tests. Despite high expectations for these tests, performance remains lower than other guideline-recommended strategies, particularly with respect to advanced precancerous lesion (APL) sensitivity. We conducted a simulation study of estimated clinical and economical outcomes for CRC screening with a blood-based test (at perfect adherence) compared to the multi-target stool-DNA (mt-sDNA) test (at published adherence rates). Methods: Utilizing CRC-AIM, a calibrated and validated microsimulation model, CRC screening outcomes were calculated for 1 million average-risk individuals screened between ages 45-75 years with triennial blood-based versus mt-sDNA testing. CRC and APL sensitivity and specificity inputs were derived from two large clinical validation studies for these screening modalities: ECLIPSE (NCT04136002) and DeeP-C (NCT01397747), respectively. To demonstrate the maximum benefits and burdens of blood-based screening, adherence to initial screening and follow-up colonoscopy after a positive blood test was modeled at 100%, while real-world adherence estimates of 65.6% were used for the mt-sDNA test. Outcomes of interest included life years-gained (LYG) and CRC cases missed by the blood-based test compared to the stool-based test, additional treatment costs imposed by theblood-based test, and additional CRC-related deaths per 1 million screened. Results: Compared to triennial screening with mt-sDNA at real-world adherence, blood-based screening at perfect adherence resulted in a higher number of incident (n=18,464) and fatal (n=6,483) CRC cases that would been avoided with the mt-sDNA test. Over a lifetime, screening with blood-based tests required 1,276,310 more tests (21% more) and 52,942 additional follow-up colonoscopies (7% more) compared to mt-sDNA screening. This increased testing burden did not generate additional benefits and instead reduced life-years gained by 67,645 per 1 million screened, resulting in an additional $1.6 billion in treatment costs compared to the mt-sDNA strategy. Conclusions: Data from this CRC-AIM modeling study show that even with perfect adherence, blood-based screening yields inferior clinical and economic benefits compared to mt-sDNA screening, due to suboptimal APL detection with the former test.

Objectives: To describe member adherence to a mail-based, health insurer-sponsored gap closure program for colorectal cancer (CRC) screening using multi-target stool DNA (mt-sDNA; Cologuard ® ) tests. Methods: Combined patient data from Exact Sciences Laboratories LLC and data from mass-mailed mt-sDNA orders placed by a large Medicare Advantage Insurance Plan were analyzed (03/01/2023-06/30/2023). Adherence and time to test return were the primary and secondary outcomes, respectively. Their association with patient characteristics was evaluated using multivariable regression. Results: Among the 3201 member-patients included (86.6% aged 65-75 years; 58.7% female), adherence rate was 49.4%, and mean time to test return was 25.5 days. After multivariable adjustment, the odds of test return were significantly higher among 65- to 75-year-olds (odds ratio [OR] = 1.59 relative to 45- to 64-year-olds), those living in small towns (OR = 1.43 relative to metropolitan-located individuals), and with digital outreach via both SMS and email (OR = 4.31 relative to no digital outreach). Time to test return was shorter in 65- to 75-year-olds than in 45- to 64-year-olds and was not associated with other patient characteristics. Conclusions: Mass-mailed mt-sDNA tests for CRC screening were associated with an overall adherence rate of about 50% in this Medicare Advantage population, with higher likelihood of test return among patients receiving digital outreach.

Abstract Introduction: Blood-based tests represent a compelling option for early detection and management of cancers and other chronic diseases. While blood-based tests may offer potential to increase patient engagement, the assumption of greater adherence in clinical practice requires further evaluation. This systematic review aimed to evaluate the real-world adherence to established blood-based tests for commonly recommended screening indications, to better inform expectations for proposed application to average-risk colorectal cancer (CRC) screening. Methods: A systematic search of PubMed, Embase, and citations was performed to identify literature published from 2010 to 2023. Studies examined adherence to routine blood-based laboratory tests with a Grade A or B recommendation per the United States Preventive Services Task Force (USPSTF) for diabetes, dyslipidemia, human immunodeficiency virus (HIV), and hepatitis C virus (HCV) in an average-risk patient population were included. In addition, prostate-specific antigen (PSA) testing adherence for prostate cancer screening (Grade-C USPSTF recommendation), the only commonly accessible blood-based single-cancer screening test for average-risk adults, was also included. Studies without venipuncture-derived blood were excluded. Results: Of 53,067 articles screened, 69 were included in the analysis. Overall, adherence rates of blood-based tests were highly variable, with median values (interquartile range, IQR) of 66.3% (11.8%), 67.8% (18.0%), 34% (28.7%), and 36.8% (30%) for diabetes, dyslipidemia, HCV, and HIV, respectively. PSA testing adherence was 37.2% (18.4%). Beyond disease type, adherence varied by study design, data source, patient characteristics, clinical setting, and study country. Information and selection bias were the most common risks of bias. Conclusions: Based on data from this comprehensive systematic review, real-world adherence to currently recommended, blood-based screening strategies is suboptimal. Future research is needed to identify the extent to which these data are generalizable to blood-based CRC screening, and to determine if/how this candidate strategy would impact clinical, economic, and health equity outcomes. Citation Format: Quang A. Le, Takako Kiener, Heather A. Johnson, Rukaiyya S. Khan, Joyce Kong, Kevin H. Li, Gina Thompson, A. Burak Ozbay, Mallik Greene, Paul J. Limburg, A. Mark Fendrick, John B. Kisiel, Derek W. Ebner. Systematic review of real-world adherence to blood-based laboratory tests for average-risk disease screening: potential implications for emerging colorectal cancer screening modalities [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A027.