Screening Initiation Age Research Articles

Genome-wide polygenic risk scores for colorectal cancer have implications for risk-based screening.

Hereditary factors, including single genetic variants and family history, can be used for targeting colorectal cancer (CRC) screening, but limited data exist on the impact of polygenic risk scores (PRS) on risk-based CRC screening. Using longitudinal health and genomics data on 453,733 Finnish individuals including 8801 CRC cases, we estimated the impact of a genome-wide CRC PRS on CRC screening initiation age through population-calibrated incidence estimation over the life course in men and women. Compared to the cumulative incidence of CRC at age 60 in Finland (the current age for starting screening in Finland), a comparable cumulative incidence was reached 5 and 11 years earlier in persons with high PRS (80-99% and >99%, respectively), while those with a low PRS (< 20%) reached comparable incidence 7 years later. The PRS was associated with increased risk of post-colonoscopy CRC after negative colonoscopy (hazard ratio 1.76 per PRS SD, 95% CI 1.54-2.01). Moreover, the PRS predicted colorectal adenoma incidence and improved incident CRC risk prediction over non-genetic risk factors. Our findings demonstrate that a CRC PRS can be used for risk stratification of CRC, with further research needed to optimally integrate the PRS into risk-based screening.

Cost-Utility Analysis for Colorectal Cancer Screening According to the Initiating Age of National Cancer Screening Program in Korea.

This study aimed to identify the most cost-effective strategy for colorectal cancer screening using the fecal immunochemical test (FIT), focusing on screening initiation age in Korea. We designed Markov simulation models targeting individuals aged 40 years or older. Twelve strategies combining screening initiation ages (40, 45, or 50 years old), termination ages (80 or no limit), and intervals (1 or 2 years) were modeled, and the most cost-effective strategy was selected. The robustness of the results was confirmed using one-way and probabilistic sensitivity analyses. Furthermore, the cost-effectiveness of the qualitative and quantitative FIT methods was verified using scenario analysis. The 2-year interval strategy with a screening age range of 45-80 years was the most cost-effective (incremental cost-utility ratio = KRW 7,281,646/quality adjusted life years). The most sensitive variables in the results were transition rate from advanced adenoma to local cancer and discount rate. The uncertainty in the model was substantially low. Moreover, strategies starting at the age of 40 years were also cost-effective but considered suboptimal. The scenario analysis showed that there was no significant difference in cost-effectiveness between strategies with various relative screening ratio of quantitative and qualitative method. The screening method for advancing the initiation age, as presented in the 2015 revised national screening recommendations, was superior regarding cost-effectiveness. This study provides a new paradigm for the development of a national cancer screening system in Korea, which can be utilized as a scientific basis for economic evaluations.

Estimated US Cancer Deaths Prevented With Increased Use of Lung, Colorectal, Breast, and Cervical Cancer Screening

Increased use of recommended screening could help achieve the Cancer Moonshot goal of reducing US cancer deaths. To estimate the number of cancer deaths that could be prevented with a 10-percentage point increase in the use of US Preventive Services Task Force (USPSTF)-recommended screening. This decision analytical model study is an extension of previous studies conducted for the USPSTF from 2018 to 2023. This study simulated contemporary cohorts of US adults eligible for lung, colorectal, breast, and cervical cancer screening. Annual low-dose computed lung tomography among eligible adults aged 50 to 80 years; colonoscopy every 10 years among adults aged 45 to 75 years; biennial mammography among female adults aged 40 to 74 years; and triennial cervical cytology screening among female adults aged 21 to 29 years, followed by human papillomavirus testing every 5 years from ages 30 to 65 years. Estimated number of cancer deaths prevented with a 10-percentage point increase in screening use, assuming screening commences at the USPSTF-recommended starting age and continues throughout the lifetime. Outcomes were presented 2 ways: (1) per 100 000 and (2) among US adults in 2021; and they were expressed among the target population at the age of screening initiation. For lung cancer, estimates were among those who will also meet the smoking eligibility criteria during their lifetime. Harms from increased uptake were also reported. A 10-percentage point increase in screening use at the age that USPSTF recommended screening commences was estimated to prevent 226 lung cancer deaths (range across models within the cancer site, 133-332 deaths), 283 (range, 263-313) colorectal cancer deaths, 82 (range, 61-106) breast cancer deaths, and 81 (1 model; no range available) cervical cancer deaths over the lifetimes of 100 000 persons eligible for screening. These rates corresponded with an estimated 1010 (range, 590-1480) lung cancer deaths prevented, 11 070 (range, 10 280-12 250) colorectal cancer deaths prevented, 1790 (range, 1330-2310) breast cancer deaths prevented, and 1710 (no range available) cervical cancer deaths prevented over the lifetimes of eligible US residents at the recommended age to initiate screening in 2021. Increased uptake was also estimated to generate harms, including 100 000 (range, 45 000-159 000) false-positive lung scans, 6000 (range, 6000-7000) colonoscopy complications, 300 000 (range, 295 000-302 000) false-positive mammograms, and 348 000 (no range available) colposcopies over the lifetime. In this decision analytical model study, a 10-percentage point increase in uptake of USPSTF-recommended lung, colorectal, breast, and cervical cancer screening at the recommended starting age was estimated to yield important reductions in cancer deaths. Achieving these reductions is predicated on ensuring equitable access to screening.

S378 Effect of Lowering Recommended Colorectal Cancer Screening Initiation Age on Clinical Practice

S378 Effect of Lowering Recommended Colorectal Cancer Screening Initiation Age on Clinical Practice

Anal cancer screening results from 18-to-34-year-old men who have sex with men living with HIV.

Men who have sex with men living with HIV (MSM LWH) are at highest risk for human papillomavirus (HPV)-associated anal cancer. There is no consensus on the optimal screening initiation age. This study aimed to assess the prevalence and severity of anal HPV disease among MSM LWH under the age of 35, which is a currently proposed screening age threshold. Between 2014 and 2020, 1255 18-to-34-year-old MSM LWH underwent anal cytology screening. 916 were co-tested for high-risk HPV (HR-HPV). 467 underwent high-resolution anoscopy (HRA) and biopsy. Cancer registry data were queried. Predictors of abnormal cytology (ie, ≥ASCUS) and histological high-grade squamous intraepithelial lesions (HSIL) were evaluated using unadjusted logistic regression models. Median age was 28 years (range, 18-34). 19% received at least one dose of HPV vaccine. Abnormal cytology rate was 65%. HR-HPV and HPV16 prevalence were 87% and 30%. Biopsy results were benign (10%), LSIL (43%) and HSIL (47%). No cases of prevalent or incident anal cancers were detected. Findings were similar between age subgroups (18-24, 25-29 and 30-34) except for a higher prevalence of AIN 3 in the 30-34 group (19%). Abnormal cytology was significantly associated with HR-HPV infection. Histological HSIL was associated with HR-HPV infection and cytological LSIL or worse. The absence of anal cancer in a large cohort of MSM LWH under the age of 35, despite high prevalence of anal HR-HPV infection and precancer, supports an age-based anal cancer screening strategy for MSM LWH.

Adenoma Detection Rate Benchmarks: An Updated Analysis.

Early-onset colorectal cancer prompted organizations to reduce the recommended screening initiation age from 50 to 45 years. The American Society for Gastrointestinal Endoscopy Quality Assurance in Endoscopy Committee recommends 3 priority quality indicators for colonoscopy services. The adenoma detection rate is considered the most important measure with the established benchmark based upon studies of patients 50 years or older. The incidence of polyps increases with age, so this change has an as-yet-unknown effect on the new benchmark. Five studies were reviewed. Based upon the results, 45- to 50-year-old patients should be included in facilities' adenoma detection rate calculations using the currently recommended benchmarks of 25% for women and men combined, or 20% for women and 30% for men when the genders are calculated separately. Males consistently had more adenomas than females in each of the 3 studies that separated genders, a detail that might merit gender-based adenoma detection rate determinations in some practices. One study indicated caution is advised; it recommends males and females be calculated separately and different benchmarks be used for each gender. The adenoma detection rate has been shown to increase over time. More studies are needed to guide screening quality metrics.

Effectiveness of Colorectal Cancer (CRC) Screening on All-Cause and CRC-Specific Mortality Reduction: A Systematic Review and Meta-Analysis.

(1) Background: The aim of this study was to pool and compare all-cause and colorectal cancer (CRC) specific mortality reduction of CRC screening in randomized control trials (RCTs) and simulation models, and to determine factors that influence screening effectiveness. (2) Methods: PubMed, Embase, Web of Science and Cochrane library were searched for eligible studies. Multi-use simulation models or RCTs that compared the mortality of CRC screening with no screening in general population were included. CRC-specific and all-cause mortality rate ratios and 95% confidence intervals were calculated by a bivariate random model. (3) Results: 10 RCTs and 47 model studies were retrieved. The pooled CRC-specific mortality rate ratios in RCTs were 0.88 (0.80, 0.96) and 0.76 (0.68, 0.84) for guaiac-based fecal occult blood tests (gFOBT) and single flexible sigmoidoscopy (FS) screening, respectively. For the model studies, the rate ratios were 0.45 (0.39, 0.51) for biennial fecal immunochemical tests (FIT), 0.31 (0.28, 0.34) for biennial gFOBT, 0.61 (0.53, 0.72) for single FS, 0.27 (0.21, 0.35) for 10-yearly colonoscopy, and 0.35 (0.29, 0.42) for 5-yearly FS. The CRC-specific mortality reduction of gFOBT increased with higher adherence in both studies (RCT: 0.78 (0.68, 0.89) vs. 0.92 (0.87, 0.98), model: 0.30 (0.28, 0.33) vs. 0.92 (0.51, 1.63)). Model studies showed a 0.62-1.1% all-cause mortality reduction with single FS screening. (4) Conclusions: Based on RCTs and model studies, biennial FIT/gFOBT, single and 5-yearly FS, and 10-yearly colonoscopy screening significantly reduces CRC-specific mortality. The model estimates are much higher than in RCTs, because the simulated biennial gFOBT assumes higher adherence. The effectiveness of screening increases at younger screening initiation ages and higher adherences.

Abstract P5-04-01: Screening Patterns of Mammography and Breast Magnetic Resonance Imaging Following Cancer Genetic Testing in an Integrated Health Care System

Abstract Background Patients at high-risk for breast cancer with genetic mutations are recommended to receive annual breast MRI in adjunct to annual mammography. Despite 15 years of clinical guidelines, uptake of annual breast MRI remains low. Further, little is known about screening patterns across genetic test results in patients tested for hereditary cancer susceptibility as part of usual care. Methods We conducted a retrospective cohort study in an integrated health system among women aged ≥18 years old, without prior breast cancer who had genetic testing for high penetrance hereditary cancer susceptibility genes between January 1, 2010 and December 31, 2018. Genetic test orders and results (pathogenic or likely pathogenic (P/LP) variant(s), negative, or variant of uncertain significance (VUS)) were obtained from health system administrative and laboratory data. Mammogram and breast MRI use data were extracted from electronic health records and claims data. To characterize screening patterns, we calculated average proportion of time covered (PTC) as the number of days covered by mammography and/or breast MRI divided by the number of days from screening eligibility until the earliest censoring event: end of observation period, reached age 75 years, breast cancer diagnosis, death, bilateral mastectomy, or disenrollment in the health system. Per National Comprehensive Cancer Network (NCCN) guidelines, women with P/LP variants in BRCA1/2, TP53, PALB2, CHEK2, ATM, and NF1 became eligible for screening on either the day they received their genetic test result or reached age eligibility and received one year of covered time for each mammogram or MRI imaging procedure received. Per Healthcare Effectiveness Data and Information Set (HEDIS) performance measures, all other women became eligible for screening at age 50 years and received two years of covered time for each mammogram received. Average PTC was calculated overall, by genetic test results, and by screening type. Poisson regression was used to determine the association between average PTC and patient-level factors (age at test, race/ethnicity, and genetic mutations) and guideline factors (recommended screening age state). Results Of 1,167 women meeting the inclusion criteria, 140 (12%) had P/LP in high penetrance breast cancer susceptibility genes (Table 1). Average PTC for individuals with a high penetrance susceptibility gene was 34.4% for MRI, 47.6% for mammogram, 63.2% for either MRI or mammogram, and 19.0% for both screening tests. The average PTC for those who tested negative, had VUS only, and had P/LP variants in genes unrelated to breast cancer was 50.3%, 44.4%, and 40.6%, respectively. Poisson regression model showed that among those with P/LP variants in high penetrance breast cancer genes, average PTC for annual MRI was positively associated with recommended screening initiation age ≥40 years (incident rate ratio [IRR]=2.07, 95% confidence interval [CI]: 1.94-2.20), higher absolute lifetime risk of breast cancer (IRR=1.38, 95% CI: 1.31-1.49), being 40-59 years old at genetic testing (IRR=1.04, 95% CI: 1.01-1.06), and non-Hispanic White race/ethnicity (IRR=1.10, 95% CI: 1.06-1.14). Conclusions Use of breast screening in women who had a P/LP variant(s) in high penetrance breast cancer susceptibility genes was low and not consistent with clinical guidelines, but comparable to the use of screening in women with negative and VUS results. Our findings suggest the need to improve screening in high-risk women with known genetic mutations and women at average risk. Table 1. Average PTC by NCCN and HEDIS recommendation. Citation Format: Boya Guo, Sarah Knerr, Karen Wernli, Kathleen Mittendorf, Heather Feigelson, Marian Gilmore, Gail Jarvik, Tia Kauffman, Erin Keast, Beth Liles, Frances Lynch, Kristin Muessig, Sonia Sasaki, David Veenstra, Jamilyn Zepp, Ben Wilfond, Katrina Goddard, Beth Devine. Screening Patterns of Mammography and Breast Magnetic Resonance Imaging Following Cancer Genetic Testing in an Integrated Health Care System [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-04-01.

Abstract B056: Increasing knowledge of colorectal cancer (CRC) risk factors and screening through a community-based education initiative

Abstract Background: Colorectal cancer (CRC) screening such as colonoscopy and stool test has been shown to be effective in reducing CRC burden, especially in the underprivileged communities. However, CRC awareness and screening uptake remained suboptimal, especially in racial/ethnic minority populations and non-Hispanic whites. Both CRC incidence and mortality rates are highest in non-Hispanic blacks (approximately 20% and 40%, respectively), and CRC screening uptake rates are lower in racial/ethnic minorities relative to non-Hispanic whites (NHWs). The cause for the disparities in incidence and mortality is multifactorial. One important aspect is the suboptimal knowledge and awareness of risk factors. Methods: To increase awareness of CRC prevention and screening, we collaborated with community-based organizations (CBOs) to develop culturally tailored educational materials targeting African/Black Americans (BAs), Asian Americans (AAs), and Hispanic Americans (HAs). The topics included essential CRC and screening knowledge, a healthy diet (Mediterranean diet), and at-home workout routines. Eligible participants from the Greater Philadelphia area and New York City participated in one-time education. Pre- and post-intervention surveys were designed based on the Colorectal Cancer Quiz provided by the Centers for Disease Control and Prevention (CDC) and were administered to assess the immediate impact of the educational sessions. Results: The analysis sample included 413 participants, among which 388 completed the post-survey. One in ten (10.3%) reported a family history of CRC, and a half (50.6%) had never had a colonoscopy. The baseline CRC knowledge score was 9.5 out of 16, indicating a moderately low level of knowledge. Participants scored particularly low on the age of CRC screening initiation, needs for screening even without symptoms, and the impact of physical activity on CRC risk. The knowledge score significantly increased to 10.9 (p &amp;lt; .001) at post-survey, indicating a significant impact of the educational workshops. Conclusion: The findings of our project confirm that the CRC screening rates are low in racial/ethnic minorities compared to the U.S. national rate of 71.6%. Meanwhile, it also confirmed that culturally tailored, community-based educational initiatives can effectively raise knowledge of CRC in medically underserved populations. Citation Format: Ellen J. Kim, LIn Zhu, Wenyue Lu, Safa Ibrahim, Steven Zhu, Nathaly Rubio-Torio, Evelyn González, Marilyn A. Fraser, Ming-Chin Yeh, Grace X. Ma, Olorunseun O. Ogunwobi, Yin Tan. Increasing knowledge of colorectal cancer (CRC) risk factors and screening through a community-based education initiative [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr B056.

Estimating the impact of reducing the age of colorectal cancer screening on cancer incidence, mortality, and costs in Canada using OncoSim.

3526 Background: Organized colorectal cancer (CRC) screening programs currently cover Canadians aged ≥50 at average-risk of developing CRC and have contributed to declining CRC incidence. Rising incidence of early-onset CRC in individuals &lt; 50 has led to lowering of the recommended screening start age to 45 rather than 50 in some jurisdictions. We used OncoSim, a publicly-available simulation tool, to model the effects of earlier screening initiation on Canadian CRC incidence, mortality and healthcare costs. Methods: OncoSim uses Canadian population and cancer registry data to simulate a representative sample of individuals from birth to death. We modeled four scenarios: no screening in average-risk individuals, screening initiation at age 50, initiation age lowered to 45 in 2022, and initiation age lowered to 40 in 2022. Each includes 32 million simulated participants. In the model, average-risk screening involves biennial FIT, available to all simulated participants regardless of family history with participation of 60% at the first recruitment attempt and 80% for repeat screening. Participants with a family history in all 4 scenarios were eligible for additional screening by colonoscopy every 5 years. Results: In our model, earlier screening yields reduced CRC incidence and mortality with increasing benefit over time. By 2051, screening initiation at age 45 or 40 reduces age-standardized incidence by 3.4% and 4.8% respectively, and age-standardized mortality by 3.3% and 4.6% respectively, compared to initiation at age 50. Screening initiation at age 45 yields 3,848 additional quality-adjusted life-years (QALYs) in 2051 at a cost of $9,350 per QALY gained and a 5% increase in colonoscopies performed. Initiation at age 40 yields 6,255 additional QALYs at $16,350 per QALY gained and a 9% increase in colonoscopies. The difference in screening costs compared to screening from age 50 is consistent year-to-year after 2024. In 2051 screening costs increase by $75mil and $155mil per year with initiation at ages 45 and 40 respectively, while costs of cancer management (including diagnosis, treatment, recurrence, palliative and end of life care) decrease by $42mil and $57mil respectively. Conclusions: Our model predicts that lowering the CRC screening initiation age for average-risk Canadians to 45 or 40 could reduce CRC incidence and mortality. Costs per QALY gained are high in the first few decades but decrease over time. Costs are modest after 30 years of screening compared to other life-preserving interventions such as dialysis. Our results suggest that lowering the screening age in Canada may be warranted, but further investigation is needed to assess capacity for increased colonoscopy demand.

Adenoma and Sessile Serrated Lesion Detection Rates at Screening Colonoscopy for Ages 45–49 Years vs Older Ages Since the Introduction of New Colorectal Cancer Screening Guidelines

All major U.S. guidelines now endorse average-risk colorectal cancer (CRC) screening at 45-49 years of age. Concerns exist that endoscopic capacity may be strained, that low-risk persons may self-select for screening, and that calculations of the adenoma detection rate may be diluted. We analyzed age-specific screening colonoscopy volumes and lesion detection rates before vs after the endorsement of CRC screening at 45-49 years of age. We compared colonoscopy volumes and lesion detection rates in our healthcare system during period 1 (October 2017 to December 2018), before the first change in guidelines, vs period 2 (January 2019 to August 2021), the era of new guidelines. The proportion of first-time screening colonoscopies performed in 45- to 49-year-olds increased from 3.5% to 11.6% (relative risk, 3.36; 95% CI, 2.45-4.61). The period 2 detection rates for adenoma, advanced adenoma, sessile serrated lesion, advanced sessile serrated lesion, adenomas per colonoscopy, and lesions per colonoscopy were very similar for 45- to 49-year-olds (34.3%, 6.3%, 8.6%, 2.9%, 0.58, and 0.69, respectively) and 50- to 54-year-olds (38.2%, 5.8%, 9.4%, 3.0%, 0.63, and 0.76, respectively) at first-time screening, and for 60- to 64-year-olds at rescreening (33.4%, 6.1%, 7.2%, 2.3%, 0.61, and 0.70, respectively). All detection rates, adenomas per colonoscopy, and lesions per colonoscopy increased from period 1 to period 2 (eg, overall adenoma detection rate 35.1% vs 42.6%; P < .0001), without any decreases among 45- to 49-year-olds. In our healthcare system, a lower CRC screening initiation age has modestly affected colonoscopy volume by age without compromising screening yield. Lesion detection rates, including for advanced adenomas, in average-risk 45- to 49-year-olds approximate those in 50- to 54-year-olds at first-time screening and 60- to 64-year-olds at rescreening. National monitoring is needed to assess fully the impact of lowering the CRC screening initiation age.

Early-onset colorectal cancer: why it should be high on our list of differentials.

BackgroundEarly‐onset colorectal cancer (EOCRC) (<50 years) incidence has increased in Australia and worldwide. However, the diagnosis of EOCRC is often delayed. Recent research has discovered some differences from later‐onset colorectal cancer (LOCRC) (>50 years). An awareness of the unique features of EOCRC is crucial to reduce time from symptom onset to diagnosis.MethodsA literature search was conducted on electronic databases (MEDLINE, EMBASE and Cochrane Library) using the search terms “early onset colorectal cancer” or “young onset colorectal cancer.”ResultsThe American Cancer Society has reduced the colorectal cancer screening initiation age to 45 for average‐risk adults whilst screening programmes in the United Kingdom and Australia remain unchanged with initiation at 60 and 50, respectively. Exposures resulting in dysbiosis (obesity, westernised diet, alcohol, antibiotic and sugar‐sweetened beverage consumption) have been linked with increased EOCRC risk. EOCRC is often left‐sided presenting with rectal bleeding, altered bowel habit and constitutional symptoms. EOCRC is more commonly sporadic than hereditary, harbouring different genetic mutations than LOCRC. Comparative survival outcomes of EOCRC and LOCRC are conflicting with studies suggesting either better or poorer survival. Young patients better tolerate treatment‐related toxicities, which may account for their improved survival despite comparatively advanced stages and poorer histopathological features at diagnosis.ConclusionCurrent EOCRC literature is limited by American‐focused datasets and heterogenous EOCRC definitions and study designs (the greatest strength of evidence exists for EOCRC risk factor studies comprised of large retrospective cohorts). There is minimal research into the quality of life and surgical outcomes of EOCRC patients, and this area warrants further investigation.

Awareness and knowledge of Colorectal Cancer Screening among Latinos in Omaha, Nebraska.

Colorectal cancer (CRC) screening rates remain low in Latino communities. We sought to determine the screening awareness and attitudes in Omaha, Nebraska. We interviewed 150 Latinos at an urban Federally Qualified Health Center, June-October 2017. Chi-square or Fisher-exact tests and multiple logistic regression models were used for data analysis. Participants reported low educational attainment, low income, and limited access to insurance or a primary provider. Less than one-third of participants aged 50 + had ever heard of FOBT (32.6%) or colonoscopy (30.4%). For individuals 50+, access to a primary care provider (p = .03) and knowing the screening initiation age (p = .03) were associated with ever having a colonoscopy. Higher knowledge score was a strong predictor of any CRC screening. Knowledge predicted screening, suggesting interventions should aim to educate this population regarding CRC screening guidelines and options and work with stakeholders to make CRC screening more accessible.

Provider preferences for anal cancer prevention screening: Results of the International Anal Neoplasia Society survey

ObjectiveThis study explores provider preferences regarding anal cancer screening indications, initiation age, tools, and referral threshold to high resolution anoscopy (HRA). MethodsInternational Anal Neoplasia Society affiliates were invited to complete an online survey. Options for initiation age and tools were delineated by sub-groups. HRA referral thresholds separately queried recommendations by patient immune status. ResultsOne hundred forty respondents participated. Although consensus was lacking with regard to specific screening initiation age, more respondents recommended younger initiation ages for men who have sex with men (MSM) living with HIV (LWH) compared with MSM not LWH (p < 0.01). “No age threshold” ranged 44-55% among sub-groups with lower genital tract disease. Cytology and digital anorectal exam (DARE) were the most frequently selected tools for all sub-groups (ranges 77-90% and 74-86%, respectively). HRA was recommended significantly more frequently for MSM LWH (58%) and patients with vulvar cancer (52%) compared to others (p < 0.01). “Any [test] abnormality” was more often selected as indication for HRA for immunocompromised (56%) and immunocompetent (46%) patients than a specific cytology test result (29%, 36% respectively). ConclusionCytology and DARE were preferred screening tools; screening initiation age and HRA referral threshold showed less consensus. Evidence-based guidelines are needed and may lead to more consistent screening practices.

Risk Stratification for Early-Onset Colorectal Cancer Using a Combination of Genetic and Environmental Risk Scores: An International Multi-Center Study.

The incidence of colorectal cancer (CRC) among individuals aged younger than 50 years has been increasing. As screening guidelines lower the recommended age of screening initiation, concerns including the burden on screening capacity and costs have been recognized, suggesting that an individualized approach may be warranted. We developed risk prediction models for early-onset CRC that incorporate an environmental risk score (ERS), including 16 lifestyle and environmental factors, and a polygenic risk score (PRS) of 141 variants. Relying on risk score weights for ERS and PRS derived from studies of CRC at all ages, we evaluated risks for early-onset CRC in 3486 cases and 3890 controls aged younger than 50 years. Relative and absolute risks for early-onset CRC were assessed according to values of the ERS and PRS. The discriminatory performance of these scores was estimated using the covariate-adjusted area under the receiver operating characteristic curve. Increasing values of ERS and PRS were associated with increasing relative risks for early-onset CRC (odds ratio per SD of ERS = 1.14, 95% confidence interval [CI] = 1.08 to 1.20; odds ratio per SD of PRS = 1.59, 95% CI = 1.51 to 1.68), both contributing to case-control discrimination (area under the curve = 0.631, 95% CI = 0.615 to 0.647). Based on absolute risks, we can expect 26 excess cases per 10 000 men and 21 per 10 000 women among those scoring at the 90th percentile for both risk scores. Personal risk scores have the potential to identify individuals at differential relative and absolute risk for early-onset CRC. Improved discrimination may aid in targeted CRC screening of younger, high-risk individuals, potentially improving outcomes.

Self-reported reasons for colonoscopy among adults aged 45-49 versus 50 years and older from 2010-2018

BackgroundIn May of 2018, the American Cancer Society lowered the age of colorectal cancer (CRC) screening initiation from 50 to 45 years and in October 2020, United States Preventive Services Task Force published draft guidelines also lowering age of screening initiation to 45 years. Evaluating guideline adherence is needed; however, the majority of prior research on cancer screening do not distinguish whether colonoscopy was performed for true screening purposes or for post-symptomatic diagnosis. MethodsUsing data from the National Health Interview Survey between 2010 to mid-2018, we assessed response to the question “What was the MAIN reason you had [last] colonoscopy?” stratified by age (45−49 versus 50+ years). Multivariable logistic regression defined adjusted odds ratios of receiving last colonoscopy for screening controlling for relevant demographic characteristics. To estimate the cost burden of colonoscopy, the proportion of respondents reporting paying out of pocket for their last colonoscopy was assessed. ResultsAmong 29,074 participants who had undergone a colonoscopy, 44.4 % of those aged 45–50 reported routine procedure as the reason for their most recent colonoscopy, as compared to 82.4 % in the 50+ age group (p < 0.001). Characteristics associated with undergoing colonoscopy as a routine procedure included Black race and male sex for both age cohorts (p < 0.01 for all). Notably, almost half (46.9 %) of participants younger than 50 years paid part of or the full cost of their colonoscopy, as compared to 30.7 % over the age of 50 (p < 0.001). ConclusionsThe majority of adults aged 45−49 self-report that last colonoscopy was not performed for screening, which is unsurprising given guidelines for screening for individuals under 50. As guidelines change, continued surveillance of colonoscopy patterns across age cohorts is needed, and studies should also incorporate reasons for testing.

Colorectal Cancer Incidence After Colonoscopy at Ages 45–49 or 50–54 Years

Colorectal cancer (CRC) incidence at ages younger than 50 years is increasing, leading to proposals to lower the CRC screening initiation age to 45 years. Data on the effectiveness of CRC screening at ages 45-49 years are lacking. We studied the association between undergoing colonoscopy at ages 45-49 or 50-54 years and CRC incidence in a retrospective population-based cohort study using Florida's linked Healthcare Cost and Utilization Project databases with mandated reporting from 2005 to 2017 and Cox models extended for time-varying exposure. Among 195,600 persons with and 2.6 million without exposure to colonoscopy at ages 45-49 years, 276 and 4844 developed CRC, resulting in CRC incidence rates of 20.8 (95% CI, 18.5-23.4) and 30.6 (95% CI, 29.8-31.5) per 100,000 person-years, respectively. Among 660,248 persons with and 2.4 million without exposure to colonoscopy at ages 50-54 years, 798 and 6757 developed CRC, resulting in CRC incidence rates of 19.0 (95% CI, 17.7-20.4) and 51.9 (95% CI, 50.7-53.1) per 100,000 person-years, respectively. The adjusted hazard ratios for incident CRC after undergoing compared with not undergoing colonoscopy were 0.50 (95% CI, 0.44-0.56) at ages 45-49 years and 0.32 (95% CI, 0.29-0.34) at ages 50-54 years. The results were similar for women and men (hazard ratio, 0.48; 95% CI, 0.40-0.57 and hazard ratio, 0.52; 95% CI, 0.43-0.62 at ages 45-49 years, and hazard ratio, 0.35; 95% CI, 0.31-0.39 and hazard ratio, 0.29; 95% CI, 0.26-0.32 at ages 50-54 years, respectively). Colonoscopy at ages 45-49 or 50-54 years was associated with substantial decreases in subsequent CRC incidence. These findings can inform screening guidelines.

Age at initiation of screening mammography by family history of breast cancer in the breast cancer surveillance consortium.

Women with a first-degree family history of breast cancer (FHBC) are sometimes advised to initiate screening mammography when they are 10 years younger than the age at which their youngest relative was diagnosed, despite a lack of unambiguous evidence that this is an effective strategy. It is unknown how often this results in women initiating screening earlier (< 40 years) than screening guidelines recommend for average-risk women. We examined screening initiation age by FHBC and age at diagnosis of the youngest relative using data collected by the Breast Cancer Surveillance Consortium on 74,838 first screening mammograms performed between 1996 and 2016. Of the 74,838 women included in the study, nearly 9% reported a FHBC. Approximately 16.8% of women who initiated mammography before 40 years reported a FHBC. More women with a FHBC than without initiated screening < 40 years (48% vs. 23%, respectively). Among women with a FHBC who initiated screening < 40 years, 65% were 10 years younger than the age at which their relative was diagnosed. Women with a first-degree relative diagnosed with breast cancer were more likely to start screening before 40 years than women reporting no FHBC, especially if their relative was diagnosed before 50 years.

Healthcare Provider Perspectives on Lowering Colorectal Cancer Screening Initiation Age to 45 Years: Results From a Survey of Clinicians in the U.S.

We conducted a survey of primary care clinicians and gastroenterologists (n = 938) between 11/06/19–12/06/19 to assess knowledge and attitudes regarding colorectal cancer screening. We assessed clinicians’ attitudes toward lowering the colorectal cancer screening initiation age to 45 years, a topic of current debate. We also evaluated provider and practice characteristics associated with agreement. Only 38.1% of primary care clinicians endorsed colorectal cancer screening initiation at age 45 years, compared to 75.5% of gastroenterologists (p < .0001). Gastroenterologists were over 5 times more likely than primary care clinicians to endorse lowering the screening initiation age (OR = 5.30, 3.54-7.93). Other factors found to be independently associated with agreement with colorectal cancer screening initiation at age 45 years included seeing more than 25 patients per day (vs. fewer) and suburban (vs. urban) location. Results emphasize the need for collaboration between primary care clinicians and gastroenterologists to ensure that patients receive consistent messaging and evidence-based care.

S0280 Lowering the Colorectal Cancer Screening Age Improves Predicted Outcomes in Pre-Medicare and Medicare Populations in the CRC-AIM Microsimulation Model

INTRODUCTION: Most US guidelines recommend average risk colorectal cancer (CRC) screening for ages 50–75. An increasing CRC incidence among younger populations renders critical the need to evaluate the potential benefit of earlier CRC screening initiation. Using the validated CRC-AIM microsimulation model, we estimated the impact of lowering the CRC screening initiation age on outcomes for triennial multitarget stool DNA (mt-sDNA) or annual fecal immunochemical test (FIT) screening strategies. METHODS: Screening strategies were simulated for individuals free of diagnosed CRC at age 40 and screened from ages 50–75 or 45–75. CRC incidence, mortality, and life-years gained (LYG) were assessed for pre-Medicare eligible and Medicare eligible years (ages 65–75). Adherence rates were assumed to be as previously reported (71% for mt-sDNA vs 43% for FIT) or perfect (100%). Predicted outcomes of screening vs no screening are per 1000 individuals. Statistical differences between ages 45 and 50 were assessed by McNemar’s test. RESULTS: For individuals who initiated screening at age 45 with reported adherence, triennial mt-sDNA and annual FIT resulted in 23.9 and 24.4 more predicted LYG, respectively, versus starting screening at age 50 (Figure 1). With reported adherence, reductions in CRC incidence with mt-sDNA were 64.5% and 61.1% at screening start ages of 45 and 50, respectively, and with FIT were 53.7% and 49.9% (both P < 0.0001). Reductions in CRC mortality with mt-sDNA were 71.7% and 68.7% at screening start ages of 45 and 50, respectively, and with FIT were 62.7% and 59.0% (both P < 0.0001). Reductions in CRC cases and deaths were observed for both pre-Medicare and Medicare populations (Figures 2-3). With reported adherence, the number of CRC cases and deaths were lower with triennial mt-sDNA than annual FIT regardless of screening start age. Improvement in outcomes with earlier screening initiation were greater when assuming reported versus perfect adherence. CONCLUSION: Non-invasive stool-based screening tests may serve as effective early screening tools among younger populations. LYG and reductions in CRC incidence and mortality are greater when beginning screening at age 45 vs age 50, with gains applying to both pre-Medicare and Medicare populations. CRC outcomes were improved with a lower initiation age for both reported and perfect adherence model assumptions. When assuming reported adherence rates, mt-sDNA confers greater benefits than FIT.Figure 1.: Life-years gained (LYG) with triennial mt-sDNA and annual FIT assuming reported or perfect adherence and screening start ages of 45 or 50 years.Figure 2.: CRC cases per 1000 individuals with triennial mt-sDNA and annual FIT assuming reported or perfect adherence and screening start ages of 45 or 50 years. Results are shown for the pre-Medicare eligibility years (ages 45– or 50–64) or during Medicare eligibility (ages 65–75).Figure 3.: CRC deaths per 1000 individuals with triennial mt-sDNA and annual FIT assuming reported or perfect adherence and screening start ages of 45 or 50 years. Results are shown for the pre-Medicare eligibility years (ages 45– or 50–64) or during Medicare eligibility (ages 65–75).