Individualizing colonoscopy screening by sex and race

Application of fecal immunochemical test in colorectal cancer screening: A community-based, cross-sectional study in average-risk individuals in Hainan

BACKGROUND

The incidence of colorectal cancer (CRC) in China is steadily rising, with a high proportion of advanced-stage diagnoses. This highlights the significance of early detection and prevention measures to enhance survival rates. Fecal immunochemical testing (FIT) is a globally recommended CRC screening method; however, limited research has been conducted on its application in Hainan.

AIM

To assess the efficacy and adherence of FIT screening among average-risk individuals in Hainan, while also examining the risk factors associated with positive FIT results.

METHODS

This population-based cross-sectional study implemented FIT screening for CRC in 2000 asymptomatic participants aged 40-75 years from five cities and 21 community health centers in Hainan Province. The study was conducted from August 2022 to April 2023, employing a stratified sampling method to select participants. Individuals with positive FIT results subsequently underwent colonoscopy. Positive predictive values for confirmed CRC and advanced adenoma were calculated, and the relationship between relevant variables and positive FIT results was analyzed using χ² tests and multivariate logistic regression.

RESULTS

A total of 1788 participants completed the FIT screening, with a median age of 57 years (interquartile range: 40-75). Among them, 503 (28.1%) were males, and 1285 (71.9%) were females, resulting in an 89.4% compliance rate for FIT screening. The overall positivity rate of FIT was 4.4% [79 out of 1788; 95% confidence interval (CI): 3%-5%]. The specific positivity rates for Haikou, Sanya, Orient City, Qionghai City, and Wuzhishan City were 9.6% (45 of 468; 95%CI: 8%-11%), 1.3% (6 of 445; 95%CI: 0.1%-3.1%), 2.7% (8 of 293; 95%CI: 1.2%-4.3%), 3.3% (9 of 276; 95%CI: 1.0%-6.3%), and 4.2% (11 of 406; 95%CI: 1.2%-7.3%), respectively. Significant associations were found between age, dietary habits, and positive FIT results. Out of the 79 participants with positive FIT results, 55 underwent colonoscopy, demonstrating an 82.2% compliance rate. Among them, 10 had a clean gastrointestinal tract, 43 had polyps or adenomas, and 2 were confirmed to have CRC, yielding a positive predictive value of 3.6% (95%CI: 0.9%-4.2%). Among the 43 participants with polyps or adenomas, 8 were diagnosed with advanced adenomas, resulting in an advanced adenoma rate of 14.5% (95%CI: 10.1%-17.7%).

CONCLUSION

In the Hainan region, FIT screening for CRC among asymptomatic individuals at average risk is feasible and well-received.

The Diagnostic Yield of Genetic Testing in Patients With Multiple Colorectal Adenomas: A Specialist Center Cohort Study

INTRODUCTION

Adenoma multiplicity is associated with increased colorectal cancer (CRC) risk. The utility of genetic testing in patients with multiple colorectal adenomas (MCRA) remains uncertain. We evaluated the diagnostic yield of mutations in polyposis- and CRC-associated genes in patients with MCRA.

METHODS

We performed a cross-sectional review of adult patients with 10-99 cumulative adenomas from the prospective database at the St Mark's Hospital Polyposis Registry and Family Cancer Clinic between 1999 and 2021. Genetic testing was performed for adenomatous polyposis-associated genes, hamartomatous polyposis-associated genes, and nonpolyposis colorectal cancer-associated genes. Clinicopathological outcomes were extracted for multiple logistic regression analysis.

RESULTS

Two hundred fifty-nine patients with MCRA (median age 61 [interquartile range 53-69] years) were identified. Sixty-six patients (25.5%) had a pathogenic variant or likely pathogenic variant, with APC and biallelic MUTYH mutations constituting the majority of identified pathogenic variant/likely pathogenic variants. Diagnostic yields were greater than 10% at any adenoma burden. In univariate analysis, higher adenoma burden and younger age were associated with higher yield (both P < 0.0001). In patients with MCRA with 10-19 adenomas without a relevant personal or family history of CRC, the diagnostic yield was nil. In multiple logistic regression analysis, higher adenoma burden, younger age, personal history of CRC, and first-degree familial history of CRC were associated with higher diagnostic yield.

DISCUSSION

Diagnostic yield of >10% at any adenoma burden supports current guidance for constitutional genetic testing in patients with MCRA, although the low yield in people older than 60 years with 10-19 adenomas suggests that a stratified approach might be appropriate.

Colorectal Cancer Risk Assessment and Precision Approaches to Screening: Brave New World or Worlds Apart?

Current colorectal cancer (CRC) screening recommendations take a "one-size-fits-all" approach using age as the major criterion to initiate screening. Precision screening that incorporates factors beyond age to risk stratify individuals could improve on current approaches and optimally use available resources with benefits for patients, providers, and health care systems. Prediction models could identify high-risk groups who would benefit from more intensive screening, while low-risk groups could be recommended less intensive screening incorporating noninvasive screening modalities. In addition to age, prediction models incorporate well-established risk factors such as genetics (eg, family CRC history, germline, and polygenic risk scores), lifestyle (eg, smoking, alcohol, diet, and physical inactivity), sex, and race and ethnicity among others. Although several risk prediction models have been validated, few have been systematically studied for risk-adapted population CRC screening. In order to envisage clinical implementation of precision screening in the future, it will be critical to develop reliable and accurate prediction models that apply to all individuals in a population; prospectively study risk-adapted CRC screening on the population level; garner acceptance from patients and providers; and assess feasibility, resources, cost, and cost-effectiveness of these new paradigms. This review evaluates the current state of risk prediction modeling and provides a roadmap for future implementation of precision CRC screening.

What Constitutes Evidence? Colorectal Cancer Screening and the U.S. Preventive Services Task Force

The United States Preventive Services Task Force is perhaps America's best-known source of evidence-based medicine (EBM) recommendations. This paper reviews aspects of the history of one such recommendation-screening for colorectal cancer (CRC)-to explore how the Task Force evaluates the best available evidence to reach its conclusions.Although the Task Force initially believed there was inadequate evidence to recommend CRC screening in the 1980s, it later changed its mind. Indeed, by 2002, it was recommending screening colonoscopy for those aged 50 and older, "extrapolating" from the existing evidence as there were no randomized controlled trials of the procedure. By 2016, due in part to the use of an emerging analytic modality known as modeling, the Task Force supported four additional CRC screening tests that lacked randomized data. Among the reasons the Task Force gave for these decisions was the desire to improve adherence for a strategy-screening healthy, asymptomatic individuals-that it believed saved lives.During these same years, the Task Force diverged from other organizations by declining to advocate screening otherwise healthy Black patients earlier than age 50-despite the fact that such individuals had higher rates of CRC than the general population, higher mortality from the disease and earlier onset of the disease. In declining to extrapolate in this instance, the Task Force underscored the lack of reliable data that proved that the benefits of such testing would outweigh the harms.The history of CRC screening reminds us that scientific evaluation relies not only on methodological sophistication but also on a combination of intellectual, cognitive and social processes. General internists-and their patients-should realize that EBM recommendations are often not definitive but rather thoughtful data-based advice.

Risk Factors of Young-Onset Colorectal Cancer: Analysis of a Large Population-Based Registry

BACKGROUND

As the third most common type of cancer in the United States, colorectal cancer (CRC) was previously thought to be rare in young populations. Despite a decrease in the overall incidence of CRC, the rate of new cases under 50 years old has been continuously increasing.

AIM

The purpose of our study was to analyze risk factors of young-onset CRC.

METHODS

Commercially available software platform, Explorys, was used to extract data from a collective healthcare database electronically.

RESULTS

In this database, 13,800 young adults (age 20-50) were diagnosed with primary colorectal malignancy. Compared to subjects with a previous family history of CRC who had an odds ratio of 17.78, those diagnosed with primary malignant neoplasm of breast and inflammatory bowel disease (ulcerative colitis and Crohn's) had odds ratios of 16.94, 4.4, and 3.7 for young-onset CRC, respectively. Patients with a history of alcohol abuse, smoking, obesity, diabetes mellitus, and hyperlipidemia had higher chances of developing young-onset CRC. In addition, the odds of CRC were lower in Hispanic ethnicity in comparison to Caucasians (OR: 0.54), with no statically significant differences between Caucasian, African American, and Asian populations.

CONCLUSION

Currently, this is an expansive study investigating the risk factors for early-onset CRC. The analysis showed factors such as family and individual history of IBD to have high association with early onset. Notably, an individual history of breast malignancy was strongly associated with early-onset CRC.

Risk Factors for the Diagnosis of Colorectal Cancer

BACKGROUND

Colorectal cancer defined as cancer of the colon or rectum, is the third most frequently diagnosed cancer in men and the second in women, and, according to the World Health Organization database GLOBOCAN, it accounts for nearly 1.4 million new cases annually worldwide. The occurrence of colorectal cancer is associated with nonmodifiable risk factors, including age and hereditary factors, as well as with modifiable environmental and lifestyle factors.

METHODS

The study included 800 patients, 400 diagnosed with colorectal cancer and 400 within the control group, who gave their written informed consent to participate in the study. Patients with cancer other than colorectal cancer were randomly selected for control group I, and patients with no cancer diagnosis were selected for control group II. The method used was a case-control study - an observational and analytical study with a control group, conducted among patients of the Clinical Oncology Centre and the Provincial Hospital in the years 2019-2020. The study comparing the exposure was carried out in a group of people who developed the endpoint, that is colorectal cancer, with the exposure in a well-matched group of controls who did not reach the endpoint. Assessment of activity and BMI was used according to WHO recommendations, as well as the expert system. The data were tested for the distribution and the homogeneity of variance was validated before applying the parameter tests. Comparison of quantitative variables between groups was performed using ANOVA.

RESULTS

The mean age of the patients was 64.53 ± 8.86 years, of the control group I - 59.64 ± 9.33 and the control group II - 57.5 (7.83). There was a strong positive association between the incidence of ulcerative colitis and the risk of colorectal cancer (P < .01). Among obese subjects, the risk of developing colorectal cancer was 1.27 (95% CI, 1.06-1.53) compared with nonobese subjects. A strong positive relationship was found between low physical activity converted to metabolic equivalent of MET effort per week and the risk of colorectal cancer (P < .001). The relative risk for current smokers was 2.17 (95% CI 1.79-2.66). There was an association between higher fat consumption and higher red meat consumption and the risk of developing colorectal cancer (P < .01).

CONCLUSIONS

Obesity, low physical activity, active and passive smoking and high salt and red meat consumption have been associated with an increased risk of colorectal cancer. These findings provide further evidence of the importance of maintaining a healthy lifestyle.

Future incidence and mortality of colorectal carcinoma in the United States: an updated overview of risk factors and preventative measures

According to the Global Cancer Observatory (GLOBOCAN) 2020, colorectal carcinoma (CRC) was the second leading cause of cancer death globally. Current literature utilizes reported databases such as Surveillance, Epidemiology, and End Results (SEER) to better understand the epidemiology of CRC. The global cancer observatory’s “Cancer Tomorrow” data visualization tools was used to predict the future incidence and mortality of colorectal cancers until 2030 as a guided tool to look over ways to reduce incidence by controlling risk factors of CRC. The total number of CRC is expected to rise by 2030, with a percent change of 17.3%. The expected percent change in colon cancer is more than rectal cancer (19.8% vs. 11.6%). The estimated number of deaths secondary to CRC is expected to increase in 2030, an estimated percent change of 22.2%. The incidence and mortality rate was higher in men vs. women; however, the gap seems to be closing on trend analysis. Major risk factors for CRC include familial syndromes, family history, race, gender, obesity, diet, alcohol, and smoking. Risk can be reduced by exercise and dietary changes, fiber intake, vitamin D, calcium, and minerals. Individualized screening based on age, gender, and additional risk factors could be an option that needs further comparative data to propose a definitive benefit over established screening guidelines.

Prevalence of Advanced Colorectal Neoplasia in Veterans: Effects of Age, Sex, and Race/Ethnicity

GOAL

We sought to quantify the independent effects of age, sex, and race/ethnicity on risk of colorectal cancer (CRC) and advanced neoplasia (AN) in Veterans.

STUDY

We conducted a retrospective, cross-sectional study of Veterans aged 40 to 80 years who had diagnostic or screening colonoscopy between 2002 and 2009 from 1 of 14 Veterans Affairs Medical Centers. Natural language processing identified the most advanced finding and location (proximal, distal). Logistic regression was used to examine the adjusted, independent effects of age, sex, and race, both overall and in screening and diagnostic subgroups.

RESULTS

Among 90,598 Veterans [mean (SD) age 61.7 (9.4) y, 5.2% (n=4673) were women], CRC and AN prevalence was 1.3% (n=1171) and 8.9% (n=8081), respectively. Adjusted CRC risk was higher for diagnostic versus screening colonoscopy [odds ratio (OR)=3.79; 95% confidence interval (CI), 3.19-4.50], increased with age, was numerically (but not statistically) higher for men overall (OR=1.53; 95% CI, 0.97-2.39) and in the screening subgroup (OR=2.24; 95% CI, 0.71-7.05), and was higher overall for Blacks and Hispanics, but not in screening. AN prevalence increased with age, and was present in 9.2% of men and 3.9% of women [adjusted OR=1.90; 95% CI, 1.60-2.25]. AN risk was 11% higher in Blacks than in Whites overall (OR=1.11; 95% CI, 1.04-1.20), was no different in screening, and was lower in Hispanics (OR=0.74; 95% CI, 0.55-0.98). Women had more proximal CRC (63% vs. 39% for men; P=0.03), but there was no difference in proximal AN (38.3% for both genders).

CONCLUSIONS

Age and race were associated with AN and CRC prevalence. Blacks had a higher overall prevalence of both CRC and AN, but not among screenings. Men had increased risk for AN, while women had a higher proportion of proximal CRC. These findings may be used to tailor when and how Veterans are screened for CRC.

Risk-stratified strategies in population screening for colorectal cancer

Colorectal cancer (CRC) screening has been demonstrated to reduce CRC incidence and mortality. However, besides such benefits, CRC screening is also associated with potential harmful effects. In an ideal world, screening would only be directed to the small proportion of the population that might potentially benefit. Risk‐based screening can be seen as a first step towards this ideal world, by redistributing screening resources from low‐risk to high‐risk individuals. In theory, this should result in scarce resources being used in individuals who benefit most, while intensity of screening is reduced in individuals who benefit less, hence improving the benefit‐harm ratio among all invitees. Available strategies that have been proposed for risk‐based CRC screening include using information on age, sex, prior screening history, lifestyle and/or genetic information. Implementation of risk‐based screening requires careful consideration of reliable risk prediction models, participation with screening and informed decision‐making. While it is important to recognise the limitations of current approaches, available evidence suggests that it might be feasible to start planning the introduction of tailored strategies within screening programmes. Implementing risk‐based screening based on age, sex and prior screening history alone would already represent a substantial improvement over current uniform screening approaches. We propose that it is time that screening programmes start there and continue striving towards more comprehensive approaches embedding primary prevention as an effective approach to lower risk for everyone.

Colorectal cancer screening in African Americans: are we following the guidelines?

PURPOSE

The age at onset, incidence, and mortality rate of colorectal cancer varies among racial groups being highest in African Americans. This increased risk led to the recommendation to begin screening at the age of 45 years. Whether the recommendation for screening of African Americans at an earlier age was implemented is unknown.

METHODS

We used data from the Cancer Control Supplement of National Health Interview Survey (NHIS) conducted in the years 2005, 2010, and 2015 to analyze demographic data and use of colorectal screening (colonoscopy, stool heme testing, sigmoidoscopy, computed tomographic colonography) among the US population between the ages of 45-49 years.

RESULTS

Data on colorectal screening was available from 6740 individuals; 16.5% were African Americans. Screening test use among African Americans in 2005, 2010, and 2015 was similar to use in Whites (i.e., 15.4% (95% CI 11.4-19.4), 28.4% (95% CI 19.3-30.4) and 20.2% (95% CI 14.8-25.5) vs. 16.9% (95% CI 15.1-18.6), 19.3% (95% CI 16.9-21.7), and 21.4% (95% CI 18.6-24.2) in 2005, 2010 and 2015, respectively. Observed screening test use rates may largely be accounted for by diagnostic exams.

CONCLUSION

The recommendation for earlier colorectal screening of African Americans has not yet resulted in increased test utilization. These results emphasize the need for multidisciplinary actions to inform and implement public health policy.

Black and White Differences in Colorectal Cancer Screening and Screening Outcomes: A Narrative Review

Racial disparities in colorectal cancer incidence are widely documented. There are two potential mechanisms for these disparities: differences in access to screening, including screening follow-up, and differences in underlying risk of colorectal cancer. We reviewed the literature for evidence of these two mechanisms. We show that higher colorectal cancer incidence in blacks relative to whites emerged only after the dissemination of screening and describe evidence of racial disparities in screening rates. In contrast to the strong evidence for differences in colorectal cancer screening utilization, there is limited evidence for racial differences in adenoma prevalence. In general, black and white patients who are screened have similar adenoma prevalence, though there is some evidence that advanced adenomas and adenomas in the proximal colon are somewhat more likely in black than white patients. We conclude that higher rates of colorectal cancer incidence among black patients are primarily driven by lower rates of colorectal cancer screening. Our findings highlight the need to increase black patients' access to quality screening to reduce colorectal cancer incidence and mortality.

Bariatric Surgery Is Associated with a Recent Temporal Increase in Colorectal Cancer Resections, Most Pronounced in Adults Below 50 Years of Age

BACKGROUND

Colorectal cancer incidence is rising in adults < 50 years old, possibly due to obesity. Having bariatric surgery (BRS) should hypothetically reduce this trend, but data are limited. This study compared trends of colorectal cancer (CRC) versus other obesity-related gastrointestinal cancers (OGCs) between morbidly obese and post-BRS subjects.

MATERIAL AND METHODS

This retrospective cohort study investigated OGC resection trends using the 2006-2013 National Inpatient Sample. Patients with prior BRS and non-BRS controls with body mass index ≥ 40 kg/m² were included (n = 30,279 total). We divided OGCs into CRC and non-CRC OGCs (esophageal, stomach, liver, gallbladder, and pancreas). We calculated OGC resection trends in patients < 50 and ≥ 50 years old using the average annual percent change (AAPC).

RESULTS

BRS patients with OGCs were younger (59.3 vs 62.3 years old), with more female gender (77.4% vs 57.1%) and White race (72.6% vs 67%) compared with controls (p < 0.05). The number of CRC resections increased across all ages in 2006-2013, especially rectal cancer for BRS patients (AAPC + 19.8%, p = 0.04). The steepest rise in early-onset CRC resections was after BRS versus a lesser increase in morbid obesity controls (AAPC + 18.7% and + 13.7%, respectively, p < 0.001). In contrast, non-CRC OGCs increased in our controls but not post-BRS. In a sensitivity analysis, estimated CRC incidence trends also increased post-BRS despite adjusting for increasing BRS prevalence.

CONCLUSION

Our findings suggest that bariatric surgery is associated with a persistent increase in early-onset CRC trends. Studies are warranted to validate our results and test the impact of bariatric surgery on early-onset CRC biological mechanisms.

The potential impact of the Affordable Care Act and Medicaid expansion on reducing colorectal cancer screening disparities in African American males

Few investigations have explored the potential impact of the Affordable Care Act on health disparity outcomes in states that chose to forgo Medicaid expansion. Filling this evidence gap is pressing as Congress grapples with controversial healthcare legislation that could phase out Medicaid expansion. Colorectal cancer (CRC) is a commonly diagnosed, preventable cancer in the US that disproportionately burdens African American men and has substantial potential to be impacted by improved healthcare insurance coverage. Our objective was to estimate the impact of the Affordable Care Act (increasing insurance through health exchanges alone or with Medicaid expansion) on colorectal cancer outcomes and economic costs among African American and White males in North Carolina (NC), a state that did not expand Medicaid. We used an individual-based simulation model to estimate the impact of ACA (increasing insurance through health exchanges alone or with Medicaid expansion) on three CRC outcomes (screening, stage-specific incidence, and deaths) and economic costs among African American and White males in NC who were age-eligible for screening (between ages 50 and 75) during the study period, years of 2013–2023. Health exchanges and Medicaid expansion improved simulated CRC outcomes overall, though the impact was more substantial among AAs. Relative to health exchanges alone, Medicaid expansion would prevent between 7.1 to 25.5 CRC cases and 4.1 to 16.4 per 100,000 CRC cases among AA and White males, respectively. Our findings suggest policies that expanding affordable, quality healthcare coverage could have a demonstrable, cost-saving impact while reducing cancer disparities.

Estimating the impact of insurance expansion on colorectal cancer and related costs in North Carolina: A population-level simulation analysis

Although screening is effective in reducing incidence, mortality, and costs of treating colorectal cancer (CRC), it remains underutilized, in part due to limited insurance access. We used microsimulation to estimate the health and financial effects of insurance expansion and reduction scenarios in North Carolina (NC). We simulated the full lifetime of a simulated population of 3,298,265 residents age-eligible for CRC screening (ages 50-75) during a 5-year period starting January 1, 2018, including polyp incidence and progression and CRC screening, diagnosis, treatment, and mortality. Insurance scenarios included: status quo, which in NC includes access to the Health Insurance Exchange (HIE) under the Affordable Care Act (ACA); no ACA; NC Medicaid expansion, and Medicare-for-all. The insurance expansion scenarios would increase percent up-to-date with screening by 0.3 and 7.1 percentage points for Medicaid expansion and Medicare-for-all, respectively, while insurance reduction would reduce percent up-to-date by 1.1 percentage points, compared to the status quo (51.7% up-to-date), at the end of the 5-year period. Throughout these individuals' lifetimes, this change in CRC screening/testing results in an estimated 498 CRC cases averted with Medicaid expansion and 6031 averted with Medicare-for-all, and an additional 1782 cases if health insurance gains associated with ACA are lost. Estimated cost savings - balancing increased CRC screening/testing costs against decreased cancer treatment costs - are approximately $30 M and $970 M for Medicaid expansion and Medicare-for-all scenarios, respectively, compared to status quo. Insurance expansion is likely to improve CRC screening both overall and in underserved populations while saving money, with the largest savings realized by Medicare.

Assessing Patient Interest in Individualized Preventive Care Recommendations

Background. Few Americans obtain all 41 guideline-recommended preventive services for nonpregnant adults. We assessed patient interest in prioritizing their preventive care needs. Methods. We conducted a mixed-methods study, with 4 focus groups (N = 28) at a single institution and a nationwide survey (N = 2,103). Participants were middle-aged and older adults with preventive care needs. We obtained reactions to written materials describing the magnitude of benefit from major preventive services, including both absolute and relative benefits. Recommendations were individualized for patient risk factors (“individualized preventive care recommendations”). Focus groups assessed patient interest, how patients would want to discuss individualized recommendations with their providers, and potential for individualized recommendations to influence patient decision making. Survey content was based on focus groups and analyzed with logistic regression. Results. Patients expressed strong interest in individualized recommendations. Among survey respondents, an adjusted 88.2% (95% confidence interval [CI] = 86.7% to 89.7%) found individualized recommendations very easy to understand, 77.2% (95% CI = 75.3% to 79.1%) considered them very useful, and 64.9% (95% CI = 62.8% to 67.0%) highly trustworthy (each ≥6/7 on Likert scale). Three quarters of participants wanted to receive their own individualized recommendations in upcoming primary care visits (adjusted proportion = 77.5%, 95% CI = 75.6% to 79.4%). Both focus group and survey participants supported shared decision making and reported that individualized recommendations would improve motivation to obtain preventive care. Half of survey respondents reported that they would be much more likely to visit their doctor if they knew individualized recommendations would be discussed, compared with 4.2% who would not be more likely to visit their doctor. Survey respondents already prioritized preventive services, stating they were most likely to choose quick/easy preventive services and least likely to choose expensive preventive services (adjusted proportions, 63.8% and 8.5%, respectively). Results were consistent in sensitivity analyses. Conclusions. Individualized preventive care recommendations are likely to be well received in primary care and might motivate patients to improve adherence to evidence-based care.

Optimal age for screening colonoscopy: a modeling study

BACKGROUND AND AIMS

Recent guidelines on colorectal cancer (CRC) screening recommend starting screening earlier than before. We performed a simulation study to examine and compare the optimal ages to have once-only screening colonoscopy and repeated colonoscopies.

METHODS

A Markov model was set up using data from the German national screening colonoscopy registry to simulate the natural history of the adenoma-carcinoma process. CRC deaths and years of potential life lost (YPLL) for a hypothetical unscreened 50-year-old German population were estimated for a single screening colonoscopy or 2 or 3 screening colonoscopies with 10-year intervals at various ages.

RESULTS

One single screening colonoscopy performed between 50 and 65 years of age was expected to reduce CRC death by 49% to 69% and YPLL by 51% to 68%. An inverted U-shaped association was found between screening age and proportion of CRC deaths or YPLL prevented. The optimal age for once-only colonoscopy that yielded the highest reductions in YPLL was around 54 years for men and 56 years for women. Estimates were approximately 6 to 8 years higher when proportions of CRC deaths prevented were examined. For 2 or 3 screening colonoscopies, the optimal starting age fell to around 50 years or even younger for both genders.

CONCLUSIONS

Based on the YPLL estimates, in a high CRC incidence and high life expectancy country like Germany, the optimal age for once-only screening colonoscopy is around 55 years and possibly slightly younger for men than for women. When 2 or more screening colonoscopies are offered with 10-year intervals, screening should start at age 50 at the latest or possibly even younger for both genders.

Costs and Cost-Effectiveness of Targeted, Personalized Risk Information to Increase Appropriate Screening by First-Degree Relatives of People With Colorectal Cancer

Background. Economic evaluations are less commonly applied to implementation interventions compared to clinical interventions. The efficacy of an implementation strategy to improve adherence to screening guidelines among first-degree relatives of people with colorectal cancer was recently evaluated in a randomized-controlled trial. Using these trial data, we examined the costs and cost-effectiveness of the intervention from societal and health care funder perspectives. Method. In this prospective, trial-based evaluation, mean costs, and outcomes were calculated. The primary outcome of the trial was the proportion of participants who had screening tests in the year following the intervention commensurate with their risk category. Quality-adjusted life years were included as secondary outcomes. Intervention costs were determined from trial records. Standard Australian unit costs for 2016/2017 were applied. Cost-effectiveness was assessed using the net benefit framework. Nonparametric bootstrapping was used to calculate uncertainty intervals (UIs) around the costs and the incremental net monetary benefit statistic. Results. Compared with usual care, mean health sector costs were $17 (95% UI [$14, $24]) higher for those receiving the intervention. The incremental cost-effectiveness ratio for the primary trial outcome was calculated to be $258 (95% UI [$184, $441]) per additional person appropriately screened. The significant difference in adherence to screening guidelines between the usual care and intervention groups did not translate into a mean quality-adjusted life year difference. Discussion. Providing information on both the costs and outcomes of implementation interventions is important to inform public health care investment decisions. Challenges in the application of cost-utility analysis hampered the interpretation of results and potentially underestimated the value of the intervention. Further research in the form of a modeled extrapolation of the intermediate increased adherence effect and distributional cost-effectiveness to include equity requirements is warranted.

Prevalence of Advanced, Precancerous Colorectal Neoplasms in Black and White Populations: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Colorectal cancer incidence and mortality are higher in black vs white populations. The reasons for these disparities are not clear, yet some guidelines recommend screening black persons for colorectal cancer starting at 40-45 years of age. We performed a systematic review and meta-analysis to compare the prevalence of advanced adenomas (AAs) and advanced precancerous colorectal neoplasms (ACNs) between asymptomatic black and white screen-eligible adults.

METHODS

We searched Ovid MEDLINE, PubMed, Embase, and the Cochrane Library to identify articles (published from 1946 through June 2017) that reported prevalence values of AA or ACN in average-risk black and white individuals undergoing screening colonoscopy. Two authors independently assessed study quality and risk for bias using a modified validated quality assessment instrument. In accord with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 2 authors independently abstracted descriptive and quantitative data from each study. We performed a random-effects meta-analysis to determine risk differences and odds ratios (ORs).

RESULTS

Of 1653 articles, we identified 9 studies for analysis that included 302,128 individuals. Six of the 9 studies were of high methodologic quality, and had a low risk for bias. In these 9 studies, the overall prevalence values for AA and ACN did not differ significantly between black (6.57%) and white (6.20%) screened individuals (OR 1.03; 95% confidence interval [CI] 0.81-1.30). In a subgroup of 5 studies, the prevalence of proximal AA and ACN was significantly higher in black (3.30%) than in white (2.42%) screened individuals (OR 1.20; 95% CI 1.12-1.30). Excluding the largest study did not affect overall prevalence (OR 0.99; CI 0.73-1.34) but did eliminate the difference in prevalence of proximal AA or ACN (OR 1.48; 95% CI 0.87-2.52).

CONCLUSIONS

In this meta-analysis, we found the overall prevalence of AA and ACN did not differ significantly between average-risk black and white persons, indicating that the age at which to begin colorectal cancer screening need not differ based on race alone.

Maternal stress and early-onset colorectal cancer

Early-onset colorectal cancer (EOCRC) is defined as colorectal cancer (CRC) diagnosed before the age of 50. Alarmingly, there has been a significant increase in EOCRC diagnoses' worldwide over the past several decades. Emerging data suggest EOCRCs have distinguishing clinical, pathological, biological and molecular features; and thus, are a fundamentally different subtype of CRCs. Unfortunately, there is no simple explanation for the causes of EOCRC. Scientifically rigorous studies are needed to determine what may be driving the challenging epidemiology of EOCRC. We contend here that a reasonable hypothesis is that prenatal risk factors such as maternal stress and associated sleeping disorders influence offspring epigenetic make-up, and shape immune system and gut health contributing to an increased risk for EOCRC.

Optimizing colorectal cancer screening by race and sex: Microsimulation analysis II to inform the American Cancer Society colorectal cancer screening guideline

BACKGROUND

Colorectal cancer (CRC) risk varies by race and sex. This study, 1 of 2 microsimulation analyses to inform the 2018 American Cancer Society CRC screening guideline, explored the influence of race and sex on optimal CRC screening strategies.

METHODS

Two Cancer Intervention and Surveillance Modeling Network microsimulation models, informed by US incidence data, were used to evaluate a variety of screening methods, ages to start and stop, and intervals for 4 demographic subgroups (black and white males and females) under 2 scenarios for the projected lifetime CRC risk for 40-year-olds: 1) assuming that risk had remained stable since the early screening era and 2) assuming that risk had increased proportionally to observed incidence trends under the age of 40 years. Model-based screening recommendations were based on the predicted level of benefit (life-years gained) and burden (required number of colonoscopies), the incremental burden-to-benefit ratio, and the relative efficiency in comparison with strategies with similar burdens.

RESULTS

When lifetime CRC risk was assumed to be stable over time, the models differed in the recommended age to start screening for whites (45 vs 50 years) but consistently recommended screening from the age of 45 years for blacks. When CRC risk was assumed to be increased, the models recommended starting at the age of 45 years, regardless of race and sex. Strategies recommended under both scenarios included colonoscopy every 10 or 15 years, annual fecal immunochemical testing, and computed tomographic colonography every 5 years through the age of 75 years.

CONCLUSIONS

Microsimulation modeling suggests that CRC screening should be considered from the age of 45 years for blacks and for whites if the lifetime risk has increased proportionally to the incidence for younger adults. Cancer 2018;124:2974-85. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Colorectal Cancer Screening: Recommendations for Physicians and Patients From the U.S. Multi-Society Task Force on Colorectal Cancer

This document updates the colorectal cancer (CRC) screening recommendations of the U.S. Multi-Society Task Force of Colorectal Cancer (MSTF), which represents the American College of Gastroenterology, the American Gastroenterological Association, and The American Society for Gastrointestinal Endoscopy. CRC screening tests are ranked in 3 tiers based on performance features, costs, and practical considerations. The first-tier tests are colonoscopy every 10 years and annual fecal immunochemical test (FIT). Colonoscopy and FIT are recommended as the cornerstones of screening regardless of how screening is offered. Thus, in a sequential approach based on colonoscopy offered first, FIT should be offered to patients who decline colonoscopy. Colonoscopy and FIT are recommended as tests of choice when multiple options are presented as alternatives. A risk-stratified approach is also appropriate, with FIT screening in populations with an estimated low prevalence of advanced neoplasia and colonoscopy screening in high prevalence populations. The second-tier tests include CT colonography every 5 years, the FIT-fecal DNA test every 3 years, and flexible sigmoidoscopy every 5 to 10 years. These tests are appropriate screening tests, but each has disadvantages relative to the tier 1 tests. Because of limited evidence and current obstacles to use, capsule colonoscopy every 5 years is a third-tier test. We suggest that the Septin9 serum assay (Epigenomics, Seattle, Wash) not be used for screening. Screening should begin at age 50 years in average-risk persons, except in African Americans in whom limited evidence supports screening at 45 years. CRC incidence is rising in persons under age 50, and thorough diagnostic evaluation of young persons with suspected colorectal bleeding is recommended. Discontinuation of screening should be considered when persons up to date with screening, who have prior negative screening (particularly colonoscopy), reach age 75 or have <10 years of life expectancy. Persons without prior screening should be considered for screening up to age 85, depending on age and comorbidities. Persons with a family history of CRC or a documented advanced adenoma in a first-degree relative age <60 years or 2 first-degree relatives with these findings at any age are recommended to undergo screening by colonoscopy every 5 years, beginning 10 years before the age at diagnosis of the youngest affected relative or age 40, whichever is earlier. Persons with a single first-degree relative diagnosed at ≥60 years with CRC or an advanced adenoma can be offered average-risk screening options beginning at age 40 years.

Colorectal Cancer Screening: Recommendations for Physicians and Patients from the U.S. Multi-Society Task Force on Colorectal Cancer

This document updates the colorectal cancer (CRC) screening recommendations of the U.S. Multi-Society Task Force of Colorectal Cancer (MSTF), which represents the American College of Gastroenterology, the American Gastroenterological Association, and The American Society for Gastrointestinal Endoscopy. CRC screening tests are ranked in 3 tiers based on performance features, costs, and practical considerations. The first-tier tests are colonoscopy every 10 years and annual fecal immunochemical test (FIT). Colonoscopy and FIT are recommended as the cornerstones of screening regardless of how screening is offered. Thus, in a sequential approach based on colonoscopy offered first, FIT should be offered to patients who decline colonoscopy. Colonoscopy and FIT are recommended as tests of choice when multiple options are presented as alternatives. A risk-stratified approach is also appropriate, with FIT screening in populations with an estimated low prevalence of advanced neoplasia and colonoscopy screening in high prevalence populations. The second-tier tests include CT colonography every 5 years, the FIT-fecal DNA test every 3 years, and flexible sigmoidoscopy every 5 to 10 years. These tests are appropriate screening tests, but each has disadvantages relative to the tier 1 tests. Because of limited evidence and current obstacles to use, capsule colonoscopy every 5 years is a third-tier test. We suggest that the Septin9 serum assay (Epigenomics, Seattle, Wash) not be used for screening. Screening should begin at age 50 years in average-risk persons, except in African Americans in whom limited evidence supports screening at 45 years. CRC incidence is rising in persons under age 50, and thorough diagnostic evaluation of young persons with suspected colorectal bleeding is recommended. Discontinuation of screening should be considered when persons up to date with screening, who have prior negative screening (particularly colonoscopy), reach age 75 or have <10 years of life expectancy. Persons without prior screening should be considered for screening up to age 85, depending on age and comorbidities. Persons with a family history of CRC or a documented advanced adenoma in a first-degree relative age <60 years or 2 first-degree relatives with these findings at any age are recommended to undergo screening by colonoscopy every 5 years, beginning 10 years before the age at diagnosis of the youngest affected relative or age 40, whichever is earlier. Persons with a single first-degree relative diagnosed at ≥60 years with CRC or an advanced adenoma can be offered average-risk screening options beginning at age 40 years.

CMOST: an open-source framework for the microsimulation of colorectal cancer screening strategies

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related mortality. CRC incidence and mortality can be reduced by several screening strategies, including colonoscopy, but randomized CRC prevention trials face significant obstacles such as the need for large study populations with long follow-up. Therefore, CRC screening strategies will likely be designed and optimized based on computer simulations. Several computational microsimulation tools have been reported for estimating efficiency and cost-effectiveness of CRC prevention. However, none of these tools is publicly available. There is a need for an open source framework to answer practical questions including testing of new screening interventions and adapting findings to local conditions.

METHODS

We developed and implemented a new microsimulation model, Colon Modeling Open Source Tool (CMOST), for modeling the natural history of CRC, simulating the effects of CRC screening interventions, and calculating the resulting costs. CMOST facilitates automated parameter calibration against epidemiological adenoma prevalence and CRC incidence data.

RESULTS

Predictions of CMOST were highly similar compared to a large endoscopic CRC prevention study as well as predictions of existing microsimulation models. We applied CMOST to calculate the optimal timing of a screening colonoscopy. CRC incidence and mortality are reduced most efficiently by a colonoscopy between the ages of 56 and 59; while discounted life years gained (LYG) is maximal at 49-50 years. With a dwell time of 13 years, the most cost-effective screening is at 59 years, at $17,211 discounted USD per LYG. While cost-efficiency varied according to dwell time it did not influence the optimal time point of screening interventions within the tested range.

CONCLUSIONS

Predictions of CMOST are highly similar compared to a randomized CRC prevention trial as well as those of other microsimulation tools. This open source tool will enable health-economics analyses in for various countries, health-care scenarios and CRC prevention strategies. CMOST is freely available under the GNU General Public License at https://gitlab.com/misselwb/CMOST.

Decrease in Incidence of Colorectal Cancer Among Individuals 50 Years or Older After Recommendations for Population-based Screening

BACKGROUND & AIMS

The incidence of colorectal cancer (CRC) in the United States is increasing among adults younger than 50 years, but incidence has decreased among older populations after population-based screening was recommended in the late 1980s. Blacks have higher incidence than whites. These patterns have prompted suggestions to lower the screening age for average-risk populations or in blacks. At the same time, there has been controversy over whether reductions in CRC incidence can be attributed to screening. We examined age-related and race-related differences in CRC incidence during a 40-year time period.

METHODS

We determined the age-standardized incidence of CRC from 1975 through 2013 by using the population-based Surveillance, Epidemiology, and End Results (SEER) program of cancer registries. We calculated incidence for 5-year age categories (20-24 years through 80-84 years and 85 years or older) for different time periods (1975-1979, 1980-1984, 1985-1989, 1990-1994, 1995-1999, 2000-2004, 2005-2009, and 2010-2013), tumor subsite (proximal colon, descending colon, and rectum), and stages at diagnosis (localized, regional, and distant). Analyses were stratified by race (white vs black).

RESULTS

There were 450,682 incident cases of CRC reported to the SEER registries during the entire period (1975-2013). Overall incidence was 75.5/100,000 white persons and 83.6/100,000 black persons. CRC incidence peaked during 1980 through 1989 and began to decrease in 1990. In whites and blacks, the decreases in incidence between the time periods of 1980-1984 and 2010-2013 were limited to the screening-age population (ages 50 years or older). Between these time periods, there was 40% decrease in incidence among whites compared with 26% decrease in incidence among blacks. Decreases in incidence were greater for cancers of the distal colon and rectum, and reductions in these cancers were greater among whites than blacks. CRC incidence among persons younger than 50 years decreased slightly between 1975-1979 and 1990. However, among persons 20-49 years old, CRC incidence increased from 8.3/100,000 persons in 1990-1994 to 11.4/100,000 persons in 2010-2013; incidence rates in younger adults were similar for whites and blacks.

CONCLUSIONS

On the basis of an analysis of the SEER cancer registries from 1975 through 2013, CRC incidence decreased only among individuals 50 years or older between the time periods of 1980-1984 and 2010-2013. Incidence increased modestly among individuals 20-49 years old between the time periods of 1990-1994 and 2010-2013. The decision of whether to recommend screening for younger populations requires a formal analysis of risks and benefits. Our observed trends provide compelling evidence that screening has had an important role in reducing CRC incidence.

Do Men and Women Need to Be Screened Differently with Fecal Immunochemical Testing? A Cost-Effectiveness Analysis

Background: Several studies suggest that test characteristics for the fecal immunochemical test (FIT) differ by gender, triggering a debate on whether men and women should be screened differently. We used the microsimulation model MISCAN-Colon to evaluate whether screening stratified by gender is cost-effective.Methods: We estimated gender-specific FIT characteristics based on first-round positivity and detection rates observed in a FIT screening pilot (CORERO-1). Subsequently, we used the model to estimate harms, benefits, and costs of 480 gender-specific FIT screening strategies and compared them with uniform screening.Results: Biennial FIT screening from ages 50 to 75 was less effective in women than men [35.7 vs. 49.0 quality-adjusted life years (QALY) gained, respectively] at higher costs (€42,161 vs. -€5,471, respectively). However, the incremental QALYs gained and costs of annual screening compared with biennial screening were more similar for both genders (8.7 QALYs gained and €26,394 for women vs. 6.7 QALYs gained and €20,863 for men). Considering all evaluated screening strategies, optimal gender-based screening yielded at most 7% more QALYs gained than optimal uniform screening and even resulted in equal costs and QALYs gained from a willingness-to-pay threshold of €1,300.Conclusions: FIT screening is less effective in women, but the incremental cost-effectiveness is similar in men and women. Consequently, screening stratified by gender is not more cost-effective than uniform FIT screening.Impact: Our conclusions support the current policy of uniform FIT screening. Cancer Epidemiol Biomarkers Prev; 26(8); 1328-36. ©2017 AACR.

Measurement of DNA damage in peripheral blood by the γ-H2AX assay as predictor of colorectal cancer risk

The detection of γ-H2AX focus is one of the most sensitive ways to monitor DNA double-strand breaks (DSBs). Although changes in γ-H2AX activity have been studied in tumor cells in colorectal cancer (CRC), changes in peripheral blood lymphocytes (PBLs) have not been examined previously. We hypothesize that higher levels of irradiation-induced γ-H2AX in PBLs may be associated with an elevated risk of colorectal cancer (CRC). In a case-control study, the baseline and ionizing radiation (IR)-induced γ-H2AX levels in PBLs from frequency-matched 320 untreated CRC patients and 320 controls were detected by a laser scanning cytometer-based immunocytochemical method. We used unconditional multivariable logistic regression to evaluate CRC risk by using the ratio of IR-induced γ-H2AX to the baseline levels with adjustment of age, sex and smoking status. We found CRC cases had significantly higher γ-H2AX ratio (1.5 vs. 1.41, P<0.0001) compared with controls. When using the median γ-H2AX ratio of controls as a cutoff point, we found higher γ-H2AX ratio was significantly associated with an increased risk of CRC (OR=6.72, 95% CI=4.54-9.94). Quartile analyses also showed significant dose-response relationship between higher γ-H2AX ratio and increased risk of CRC (P for trend<0.0001). Age, sex, BMI and smoking status also influenced the association of γ-H2AX ratio with CRC risk; however, no interactions with γ-H2AX ratio were observed. These results support the premise that DSBs in peripheral blood as measured by γ-H2AX level might represent an intermediate phenotype to assess the risk of CRC. Future prospective studies are necessary to confirm our findings in independent populations.

Modeling Individual Patient Preferences for Colorectal Cancer Screening Based on Their Tolerance for Complications Risk

INTRODUCTION

Recommendations for colorectal cancer screening encourage patients to choose among various screening methods based on individual preferences for benefits, risks, screening frequency, and discomfort. We devised a model to illustrate how individuals with varying tolerance for screening complications risk might decide on their preferred screening strategy.

METHODS

We developed a discrete-time Markov mathematical model that allowed hypothetical individuals to maximize expected lifetime utility by selecting screening method, start age, stop age, and frequency. Individuals could choose from stool-based testing every 1 to 3 years, flexible sigmoidoscopy every 1 to 20 years with annual stool-based testing, colonoscopy every 1 to 20 years, or no screening. We compared the life expectancy gained from the chosen strategy with the life expectancy available from a benchmark strategy of decennial colonoscopy.

RESULTS

For an individual at average risk of colorectal cancer who was risk neutral with respect to screening complications (and therefore was willing to undergo screening if it would actuarially increase life expectancy), the model predicted that he or she would choose colonoscopy every 10 years, from age 53 to 73 years, consistent with national guidelines. For a similar individual who was moderately averse to screening complications risk (and therefore required a greater increase in life expectancy to accept potential risks of colonoscopy), the model predicted that he or she would prefer flexible sigmoidoscopy every 12 years with annual stool-based testing, with 93% of the life expectancy benefit of decennial colonoscopy. For an individual with higher risk aversion, the model predicted that he or she would prefer 2 lifetime flexible sigmoidoscopies, 20 years apart, with 70% of the life expectancy benefit of decennial colonoscopy.

CONCLUSION

Mathematical models may formalize how individuals with different risk attitudes choose between various guideline-recommended colorectal cancer screening strategies.

Differential eligibility of African American and European American lung cancer cases using LDCT screening guidelines

Introduction

Lung cancer incidence and mortality is higher among African Americans compared with European Americans in the USA where screening guidelines are currently in place and based on age at diagnosis and smoking history. Given the different smoking patterns observed in these populations and the earlier age at which African Americans are diagnosed, it is possible that African Americans will be disproportionally excluded from screening programmes.

Methods

We assessed the capture of African American and EA lung cancer cases using the National Lung Screening Trial, US Preventive Services Task Force and Centers for Medicare and Medicaid Services eligibility guidelines in a population of lung cancer cases diagnosed between 1998 and 2014 in the Baltimore region of Maryland (n=1658).

Results

We found an absolute increase of 3.8% (relative increase: 11.5%) of EA lung cancer cases that fell within the eligible screening guidelines when compared with African Americans. This difference in proportions was not statistically significant (p=0.134). However, differences were more pronounced among women, where an absolute and relative difference of 4.2% and 13.6%, respectively, was observed (p=0.083). As more EA are likely to successfully quit smoking compared with African Americans, the inclusion of the time since quitting variable decreased the relative differences in eligibility.

Conclusions

Current screening guidelines are projected to capture a higher proportion of EA lung cancer cases than African American cases; however, the differences are not statistically significant. Further studies are needed, especially among high-risk populations, to determine if racial differences in eligibility criteria for lung screening will lead to a widening of cancer health disparities.

Colorectal Cancer in African Americans: An Update

This review is an update to the American College of Gastroenterology (ACG) Committee on Minority Affairs and Cultural Diversity's paper on colorectal cancer (CRC) in African Americans published in 2005. Over the past 10 years, the incidence and mortality rates of CRC in the United States has steadily declined. However, reductions have been strikingly much slower among African Americans who continue to have the highest rate of mortality and lowest survival when compared with all other racial groups. The reasons for the health disparities are multifactorial and encompass physician and patient barriers. Patient factors that contribute to disparities include poor knowledge of benefits of CRC screening, limited access to health care, insurance status along with fear and anxiety. Physician factors include lack of knowledge of screening guidelines along with disparate recommendations for screening. Earlier screening has been recommended as an effective strategy to decrease observed disparities; currently the ACG and American Society of Gastrointestinal Endoscopists recommend CRC screening in African Americans to begin at age 45. Despite the decline in CRC deaths in all racial and ethnic groups, there still exists a significant burden of CRC in African Americans, thus other strategies including educational outreach for health care providers and patients and the utilization of patient navigation systems emphasizing the importance of screening are necessary. These strategies have been piloted in both local communities and Statewide resulting in notable significant decreases in observed disparities.

Personalizing colonoscopy screening for elderly individuals based on screening history, cancer risk, and comorbidity status could increase cost effectiveness

BACKGROUND & AIMS

Colorectal cancer (CRC) screening decisions for elderly individuals are often made primarily on the basis of age, whereas other factors that influence the effectiveness and cost effectiveness of screening are often not considered. We investigated the relative importance of factors that could be used to identify elderly individuals most likely to benefit from CRC screening and determined the maximum ages at which screening remains cost effective based on these factors.

METHODS

We used a microsimulation model (Microsimulation Screening Analysis-Colon) calibrated to the incidence of CRC in the United States and the prevalence of adenomas reported in autopsy studies to determine the appropriate age at which to stop colonoscopy screening in 19,200 cohorts (of 10 million individuals), defined by sex, race, screening history, background risk for CRC, and comorbidity status. We applied a willingness-to-pay threshold of $100,000 per quality-adjusted life-year (QALY) gained.

RESULTS

Less intensive screening history, higher background risk for CRC, and fewer comorbidities were associated with cost-effective screening at older ages. Sex and race had only a small effect on the appropriate age to stop screening. For some individuals likely to be screened in current practice (for example, 74-year-old white women with moderate comorbidities, half the average background risk for CRC, and negative findings from a screening colonoscopy 10 years previously), screening resulted in a loss of QALYs, rather than a gain. For some individuals unlikely to be screened in current practice (for example, 81-year-old black men with no comorbidities, an average background risk for CRC, and no previous screening), screening was highly cost effective. Although screening some previously screened, low-risk individuals was not cost effective even when they were 66 years old, screening some healthy, high-risk individuals remained cost effective until they reached the age of 88 years old.

CONCLUSIONS

The current approach to CRC screening in elderly individuals, in which decisions are often based primarily on age, is inefficient, resulting in underuse of screening for some and overuse of screening for others. CRC screening could be more effective and cost effective if individual factors for each patient are considered.

Risk Prediction Models for Colorectal Cancer: A Systematic Review

Colorectal cancer is the second leading cause of cancer-related death in Europe and the United States. Survival is strongly related to stage at diagnosis and population-based screening reduces colorectal cancer incidence and mortality. Stratifying the population by risk offers the potential to improve the efficiency of screening. In this systematic review we searched Medline, EMBASE, and the Cochrane Library for primary research studies reporting or validating models to predict future risk of primary colorectal cancer for asymptomatic individuals. A total of 12,808 papers were identified from the literature search and nine through citation searching. Fifty-two risk models were included. Where reported (n = 37), half the models had acceptable-to-good discrimination (the area under the receiver operating characteristic curve, AUROC >0.7) in the derivation sample. Calibration was less commonly assessed (n = 21), but overall acceptable. In external validation studies, 10 models showed acceptable discrimination (AUROC 0.71-0.78). These include two with only three variables (age, gender, and BMI; age, gender, and family history of colorectal cancer). A small number of prediction models developed from case-control studies of genetic biomarkers also show some promise but require further external validation using population-based samples. Further research should focus on the feasibility and impact of incorporating such models into stratified screening programmes.

Derivation and Validation of a Scoring System to Stratify Risk for Advanced Colorectal Neoplasia in Asymptomatic Adults: A Cross-sectional Study

BACKGROUND

Several methods are recommended equally strongly for colorectal cancer screening in average-risk persons. Risk stratification would enable tailoring of screening within this group, with less invasive tests (sigmoidoscopy or occult blood tests) for lower-risk persons and colonoscopy for higher-risk persons.

OBJECTIVE

To create a risk index for advanced neoplasia (colorectal cancer and adenomas or serrated polyps ≥1.0 cm, villous histology, or high-grade dysplasia) anywhere in the colorectum, using the most common risk factors for colorectal neoplasia.

DESIGN

Cross-sectional study.

SETTING

Multiple endoscopy units, primarily in the Midwest.

PATIENTS

Persons aged 50 to 80 years undergoing initial screening colonoscopy (December 2004 to September 2011).

MEASUREMENTS

Derivation and validation of a risk index based on points from regression coefficients for age, sex, waist circumference, cigarette smoking, and family history of colorectal cancer.

RESULTS

Among 2993 persons in the derivation set, prevalence of advanced neoplasia was 9.4%. Risks for advanced neoplasia in persons at very low, low, intermediate, and high risk were 1.92% (95% CI, 0.63% to 4.43%), 4.88% (CI, 3.79% to 6.18%), 9.93% (CI, 8.09% to 12.0%), and 24.9% (CI, 21.1% to 29.1%), respectively (P < 0.001). Sigmoidoscopy to the descending colon in the low-risk groups would have detected 51 of 70 (73% [CI, 61% to 83%]) advanced neoplasms. Among 1467 persons in the validation set, corresponding risks for advanced neoplasia were 1.65% (CI, 0.20% to 5.84%), 3.31% (CI, 2.08% to 4.97%), 10.9% (CI, 8.26% to 14.1%), and 22.3% (CI, 16.9% to 28.5%), respectively (P < 0.001). Sigmoidoscopy would have detected 21 of 24 (87.5% [CI, 68% to 97%]) advanced neoplasms.

LIMITATIONS

Split-sample validation; results apply to first-time screening.

CONCLUSION

This index stratifies risk for advanced neoplasia among average-risk persons by identifying lower-risk groups for which noncolonoscopy strategies may be effective and efficient and a higher-risk group for which colonoscopy may be preferred.

PRIMARY FUNDING SOURCE

National Cancer Institute, Walther Cancer Institute, Indiana University Simon Cancer Center, and Indiana Clinical and Translational Sciences Institute.

Screening for colorectal cancer in African Americans: determinants and rationale for an earlier age to commence screening

Colorectal cancer (CRC) screening is a cost-effective approach to reduce morbidity, mortality, and prevalence of CRC in populations. Current recommendations for asymptomatic populations begin screening at age 50 years, after which ~95% of cancers occur. Determinants that modify timing and frequency for screening include: personal/family history of adenomas or CRC, age of onset of lesions, and presence or potential to harbor high-risk conditions like inflammatory bowel disease (IBD), familial adenomatous polyposis (FAP), or Lynch syndrome. Although race, like family history, is heritable, it has not engendered inclusion in systematic screening recommendations despite multiple studies demonstrating disparity in the incidence and mortality from CRC, and the potential for targeted screening to reduce disparity. African Americans, when compared to Caucasians, have lower CRC screening utilization, younger presentation for CRC, higher CRC prevalence at all ages, and higher proportion of CRCs before age 50 years (~11 vs. 5%); are less likely to transmit personal/family history of adenomas or CRC that may change screening age; show excess of high-risk proximal adenomas, matched with 7-15% excess right-sided CRCs that lack microsatellite instability; show higher frequencies of high-risk adenomas for every age decile; and demonstrate genetic biomarkers associated with metastasis. These epidemiological and biological parameters put African Americans at higher risk from CRC irrespective of socioeconomic issues, like IBD, FAP, and Lynch patients. Including race as a factor in national CRC screening guidelines and commencing screening at an age earlier than 50 years seems rational based on the natural history and aggressive behavior in this population.

Prospective cross-sectional study on faecal immunochemical tests: sex specific cut-off values to obtain equal sensitivity for colorectal cancer?

Background

Faecal immunochemical tests (FITs) are commonly used in colorectal cancer (CRC) screening. Diagnostic accuracy of FIT differs between males and females. This so far unexplained difference could result in a dissimilarity in screening outcome between both sexes. The aim of this study is to compare sensitivity and specificity of a FIT between males and females, and study potential explanatory variables.

Methods

In this cross-sectional study, data were prospectively collected. 3,022 subjects performed a FIT prior to complete colonoscopy. Sensitivity, specificity, and ROC curves were compared for both sexes. Potential explanatory variables of the relation between sensitivity and sex were explored.

Results

At all cut-off values, FIT sensitivity for CRC was higher (range 13-23%) and specificity was lower (range 2-4%) in males compared to females. At 75 ng/ml, sensitivity for CRC was 93% in males compared to 71% in females (p = 0.03), and specificity was 90% in males compared to 93% in females (p = <0.05). For advanced adenomas, males had a slightly higher sensitivity and lower specificity (not significant). At 75 ng/ml, sensitivity for advanced adenomas was 33% in males compared to 29% in females (p = 0.46), and specificity was 93% in males compared to 95% in females (p = 0.22). ROC curves were similar for both sexes, and equal combinations of sensitivity and specificity could be achieved by adjusting the cut-off values. For CRC, the difference in sensitivity could not be explained by age or location of the tumour.

Conclusions

FIT has a higher sensitivity and a lower specificity for CRC in males than in females. Equal test characteristics can be achieved by allowing separate cut-off values for both sexes. Location and age do not explain the observed differences in sensitivity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-014-0217-7) contains supplementary material, which is available to authorized users.

Personalizing colorectal cancer screening: a systematic review of models to predict risk of colorectal neoplasia

BACKGROUND & AIMS

A valid risk prediction model for colorectal neoplasia would allow patients to be screened for colorectal cancer (CRC) on the basis of risk. We performed a systematic review of studies reporting risk prediction models for colorectal neoplasia.

METHODS

We conducted a systematic search of MEDLINE, Scopus, and Cochrane Library databases from January 1990 through March 2013 and of references in identified studies. Case-control, cohort, and cross-sectional studies that developed or attempted to validate a model to predict risk of colorectal neoplasia were included. Two reviewers independently extracted data and assessed model quality. Model quality was considered to be good for studies that included external validation, fair for studies that included internal validation, and poor for studies with neither.

RESULTS

Nine studies developed a new prediction model, and 2 tested existing models. The models varied with regard to population, predictors, risk tiers, outcomes (CRC or advanced neoplasia), and range of predicted risk. Several included age, sex, smoking, a measure of obesity, and/or family history of CRC among the predictors. Quality was good for 6 models, fair for 2 models, and poor for 1 model. The tier with the largest population fraction (low, intermediate, or high risk) depended on the model. For most models that defined risk tiers, the risk difference between the highest and lowest tier ranged from 2-fold to 4-fold. Two models reached the 0.70 threshold for the C statistic, typically considered to indicate good discriminatory power.

CONCLUSIONS

Most current colorectal neoplasia risk prediction models have relatively weak discriminatory power and have not demonstrated generalizability. It remains to be determined how risk prediction models could inform CRC screening strategies.

Race, ethnicity, and sex affect risk for polyps >9 mm in average-risk individuals

BACKGROUND & AIMS

Colorectal cancer risk differs based on patient demographics. We aimed to measure the prevalence of significant colorectal polyps in average-risk individuals and to determine differences based on age, sex, race, or ethnicity.

METHODS

In a prospective study, colonoscopy data were collected, using an endoscopic report generator, from 327,785 average-risk adults who underwent colorectal cancer screening at 84 gastrointestinal practice sites from 2000 to 2011. Demographic characteristics included age, sex, race, and ethnicity. The primary outcome was the presence of suspected malignancy or large polyp(s) >9 mm. The benchmark risk for age to initiate screening was based on white men, 50-54 years old.

RESULTS

Risk of large polyps and tumors increased progressively in men and women with age. Women had lower risks than men in every age group, regardless of race. Blacks had higher risk than whites from ages 50 through 65 years and Hispanics had lower risk than whites from ages 50 through 80 years. The prevalence of large polyps was 6.2% in white men 50-54 years old. The risk was similar among the groups of white women 65-69 years old, black women 55-59 years old, black men 50-54 years old, Hispanic women 70-74 years old, and Hispanic men 55-59 years old. The risk of proximal large polyps increased with age, female sex, and black race.

CONCLUSIONS

There are differences in the prevalence and location of large polyps and tumors in average-risk individuals based on age, sex, race, and ethnicity. These findings could be used to select ages at which specific groups should begin colorectal cancer screening.

Should colorectal cancer screening be considered in elderly persons without previous screening? A cost-effectiveness analysis

BACKGROUND

The U.S. Preventive Services Task Force recommends against routine screening for colorectal cancer (CRC) in adequately screened persons older than 75 years but does not address the appropriateness of screening in elderly persons without previous screening.

OBJECTIVE

To determine at what ages CRC screening should be considered in unscreened elderly persons and to determine which test is indicated at each age.

DESIGN

Microsimulation modeling study.

DATA SOURCES

Observational and experimental studies.

TARGET POPULATION

Unscreened persons aged 76 to 90 years with no, moderate, and severe comorbid conditions.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

One-time colonoscopy, sigmoidoscopy, or fecal immunochemical test (FIT) screening.

OUTCOME MEASURES

Quality-adjusted life-years gained, costs, and costs per quality-adjusted life-year gained.

RESULTS OF BASE-CASE ANALYSIS

In unscreened elderly persons with no comorbid conditions, CRC screening was cost-effective up to age 86 years. Screening with colonoscopy was indicated up to age 83 years, sigmoidoscopy was indicated at age 84 years, and FIT was indicated at ages 85 and 86 years. In unscreened persons with moderate comorbid conditions, screening was cost-effective up to age 83 years (colonoscopy indicated up to age 80 years, sigmoidoscopy at age 81 years, and FIT at ages 82 and 83 years). In unscreened persons with severe comorbid conditions, screening was cost-effective up to age 80 years (colonoscopy indicated up to age 77 years, sigmoidoscopy at age 78 years, and FIT at ages 79 and 80 years).

RESULTS OF SENSITIVITY ANALYSES

Results were most sensitive to assuming a lower willingness to pay per quality-adjusted life-year gained.

LIMITATION

Only persons at average risk for CRC were considered.

CONCLUSION

In unscreened elderly persons CRC screening should be considered well beyond age 75 years. A colonoscopy is indicated at most ages.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Cost-effectiveness of family history-based colorectal cancer screening in Australia

Background

With 14.234 diagnoses and over 4047 deaths reported in 2007, colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related mortality in Australia. The direct treatment cost has recently been estimated to be around AU$1.2 billion for the year 2011, which corresponds to a four-fold increase, compared the cost reported in 2001. Excluding CRCs due to known rare genetic disorders, 20% to 25% of all CRCs occur in a familial aggregation setting due to genetic variants or shared environmental risk factors that are yet to be characterised. A targeted screening strategy addressed to this segment of the population is a potentially valuable tool for reducing the overall burden of CRC.

Methods

We developed a Markov model to assess the cost-effectiveness of three screening strategies offered to people at increased risk due to a strong family history of CRC. The model simulated the evolution of a cohort of 10,000 individuals from age 50 to 90 years. We compared screening with biennial iFOBT, five-yearly colonoscopy and ten-yearly colonoscopy versus the current strategy of the Australian National Bowel Cancer Screening Programme (i.e. base case).

Results

Under the NBCSP scenario, 6,491 persons developed CRC with an average screening lifetime cost of AU$3,441 per person. In comparison, screening with biennial iFOBT, colonoscopy every ten years, and colonoscopy every five years reduced CRC incidence by 27%, 35% and 60%, and mortality by 15%, 26% and 46% respectively. All three screening strategies had a cost under AU$50,000 per life year gained, which is regarded as the upper limit of acceptable cost-effectiveness in the Australian health system. At AU$12,405 per life year gained and an average lifetime expectancy of 16.084 years, five-yearly colonoscopy screening was the most cost-effective strategy.

Conclusion

The model demonstrates that intensive CRC screening strategies targeting people at increased risk would be cost-effective in the Australian context. Our findings provide evidence that substantial health benefits can be generated from risk-based CRC screening at a relatively modest incremental cost.

Simulation models for socioeconomic inequalities in health: a systematic review

Background: The emergence and evolution of socioeconomic inequalities in health involves multiple factors interacting with each other at different levels. Simulation models are suitable for studying such complex and dynamic systems and have the ability to test the impact of policy interventions in silico. Objective: To explore how simulation models were used in the field of socioeconomic inequalities in health. Methods: An electronic search of studies assessing socioeconomic inequalities in health using a simulation model was conducted. Characteristics of the simulation models were extracted and distinct simulation approaches were identified. As an illustration, a simple agent-based model of the emergence of socioeconomic differences in alcohol abuse was developed. Results: We found 61 studies published between 1989 and 2013. Ten different simulation approaches were identified. The agent-based model illustration showed that multilevel, reciprocal and indirect effects of social determinants on health can be modeled flexibly. Discussion and Conclusions: Based on the review, we discuss the utility of using simulation models for studying health inequalities, and refer to good modeling practices for developing such models. The review and the simulation model example suggest that the use of simulation models may enhance the understanding and debate about existing and new socioeconomic inequalities of health frameworks.

Review of economic evidence in the prevention and early detection of colorectal cancer

This paper aims to systematically review the cost-effectiveness evidence, and to provide a critical appraisal of the methods used in the model-based economic evaluation of CRC screening and subsequent surveillance. A search strategy was developed to capture relevant evidence published 1999-November 2012. Databases searched were MEDLINE, EMBASE, National Health Service Economic Evaluation (NHS EED), EconLit, and HTA. Full economic evaluations that considered costs and health outcomes of relevant intervention were included. Sixty-eight studies which used either cohort simulation or individual-level simulation were included. Follow-up strategies were mostly embedded in the screening model. Approximately 195 comparisons were made across different modalities; however, strategies modelled were often simplified due to insufficient evidence and comparators chosen insufficiently reflected current practice/recommendations. Studies used up-to-date evidence on the diagnostic test performance combined with outdated information on CRC treatments. Quality of life relating to follow-up surveillance is rare. Quality of life relating to CRC disease states was largely taken from a single study. Some studies omitted to say how identified adenomas or CRC were managed. Besides deterministic sensitivity analysis, probabilistic sensitivity analysis (PSA) was undertaken in some studies, but the distributions used for PSA were rarely reported or justified. The cost-effectiveness of follow-up strategies among people with confirmed adenomas are warranted in aiding evidence-informed decision making in response to the rapidly evolving technologies and rising expectations.

The Effect of Race/Ethnicity on the Age of Colon Cancer Diagnosis

BACKGROUND

Colorectal cancer is the third most commonly diagnosed cancer in the United States. Notably, racial/ethnic disparities exist in both incidence and mortality.

PURPOSE

The aim of this case study was to investigate the impact of race/ethnicity on age at diagnosis of colorectal cancer in a defined population in Suffolk County, NY.

METHODS

Data were retrospectively collected on race/ethnicity, health insurance status, age at diagnosis, stage at diagnosis, gender, smoking status, alcohol intake, tumor location, and body mass index for colorectal cancer patients with medical records in the Stony Brook University Medical Center database (2005-2011). Population-based data on Hispanic and non-Hispanic Whites were obtained from the Surveillance, Epidemiology, and End Results registry of New York State for an overlapping time period. Permutation-based ANCOVA and logistic regression with stepwise variable selection were conducted to identify covariates and first-order interactions associated with younger age at diagnosis and cancer stage as a dependent categorical variable.

RESULTS

Of 328 colorectal cancer patients, Hispanics were diagnosed at a median younger age of 57y vs. 67y than non-Hispanic Whites (FDR = 0.001). Twenty-six percent of Hispanics were diagnosed with colorectal cancer prior to the recommended age (50y) for colorectal cancer surveillance compared to 11% of non-Hispanic Whites (FDR =0.007). Analysis of New York State registry data corroborated our findings that Hispanic colorectal cancer patients were diagnosed at a median younger age than non-Hispanic Whites. Permutation-based ANCOVA identified race/ethnicity and health insurance as significantly associated with age of diagnosis (P=0.001). Logistic regression selected (younger) age at diagnosis as being significantly associated with stage IV disease. The limitations of the case study reside in the use of self-reporting of race and ethnicity and in the small sample sizes.

CONCLUSIONS

Hispanics may be at higher risk for colorectal cancer (<50>y) and younger age at diagnosis is associated with advanced disease.

Impact of comorbidity on colorectal cancer screening cost-effectiveness study in diabetic populations

BACKGROUND

Although comorbidity has been shown to affect the benefits and risks of colorectal cancer (CRC) screening, it has not been accounted for in prior cost-effectiveness analyses of CRC screening.

OBJECTIVE

To evaluate the impact of diagnosis of diabetes mellitus, a highly prevalent comorbidity in U.S. adults aged 50 and older, on health and economic outcomes of CRC screening.

DESIGN

Cost-effectiveness analysis using an integrated modeling framework.

DATA SOURCES

Derived from basic and epidemiologic studies, clinical trials, cancer registries, and a colonoscopy database.

TARGET POPULATION

U.S. 50-year-old population.

TIME HORIZON

Lifetime.

PERSPECTIVE

Costs are based on Medicare reimbursement rates.

INTERVENTIONS

Colonoscopy screening at ten-year intervals, beginning at age 50, and discontinued after age 50, 60, 70, 80 or death.

OUTCOME MEASURES

Health outcomes and cost effectiveness.

RESULTS OF BASE-CASE ANALYSIS

Diabetes diagnosis significantly affects cost-effectiveness of CRC screening. For the same CRC screening strategy, a person without diabetes at age 50 gained on average 0.07-0.13 life years more than a person diagnosed with diabetes at age 50 or younger. For a population of 1,000 patients diagnosed with diabetes at baseline, increasing stop age from 70 years to 80 years increased quality-adjusted life years (QALYs) gained by 0.3, with an incremental cost-effectiveness ratio of $206,671/QALY. The corresponding figures for 1,000 patients without diabetes are 2.3 QALYs and $46,957/QALY.

RESULTS OF SENSITIVITY ANALYSIS

Cost-effectiveness results are sensitive to cost of colonoscopy and adherence to colonoscopy screening.

LIMITATIONS

Results depend on accuracy of model assumptions.

CONCLUSION

Benefits of CRC screening differ substantially for patients with and without diabetes. Screening for CRC in patients diagnosed with diabetes at age 50 or younger is not cost-effective beyond age 70. Screening recommendations should be individualized based on the presence of comorbidities.