Risk of Advanced Neoplasia Using the National Cancer Institute's Colorectal Cancer Risk Assessment Tool

Joint Asian Pacific Association of Gastroenterology (APAGE)-Asian Pacific Society of Digestive Endoscopy (APSDE) clinical practice guidelines on the use of non-invasive biomarkers for diagnosis of colorectal neoplasia

Screening for colorectal cancer (CRC) is effective in reducing CRC related mortality. Current screening methods include endoscopy based and biomarker based approaches. This guideline is a joint official statement of the Asian Pacific Association of Gastroenterology (APAGE) and the Asian Pacific Society of Digestive Endoscopy (APSDE), developed in response to the increasing use of, and accumulating supportive evidence for the role of, non-invasive biomarkers for the diagnosis of CRC and its precursor lesions. A systematic review of 678 publications and a two stage Delphi consensus process involving 16 clinicians in various disciplines was undertaken to develop 32 evidence based and expert opinion based recommendations for the use of faecal immunochemical tests, faecal based tumour biomarkers or microbial biomarkers, and blood based tumour biomarkers for the detection of CRC and adenoma. Comprehensive up-to-date guidance is provided on indications, patient selection and strengths and limitations of each screening tool. Future research to inform clinical applications are discussed alongside objective measurement of research priorities. This joint APAGE-APSDE practice guideline is intended to provide an up-to-date guide to assist clinicians worldwide in utilising non-invasive biomarkers for CRC screening; it has particular salience for clinicians in the Asia-Pacific region.

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.

Using Online Colorectal Cancer Risk Calculators to Guide Screening Decision-Making

BACKGROUND

Several online calculators estimate colorectal cancer risk, but their consistency is unknown. Our objectives were to quantify the variation in predicted risk and to determine which calculators are best used in the clinical setting.

METHODS

We used the Google search engine to identify online colorectal cancer risk calculators and assessed the output of each for 3 hypothetical screening scenarios (low-, average-, and high-risk), varied by age (50, 62, 75 years), sex, and race (Black, White), with risk levels based on risk-appropriate values for variables in each model. Estimated risks for models within a given scenario were rated as consistent or inconsistent based on comparison with either the absolute magnitude of difference or average lifetime risk of colorectal cancer. Summary statistics for consistent and inconsistent estimates were compared using chi-square and Fisher's exact tests.

RESULTS

We identified 5 online colorectal cancer risk calculators. Inconsistencies were found in none of 5-year, 19% of 10-year, and 81% of lifetime colorectal cancer risk estimate comparisons (P < .001). For a 50-year-old, 22% of risk estimate comparisons were inconsistent, vs 33% for a 62-year-old, and 36% for a 75-year-old (P = 0.14).

CONCLUSIONS

Online colorectal cancer risk models are more consistent in predicting colorectal cancer risk for 5- and 10-year time frames compared with lifetime. For a US population, the National Cancer Institute's Colorectal Cancer Risk Assessment Tool is a rigorously developed calculator that can be used in the clinical setting to provide 5-year and lifetime risk estimates.

Faecal occult blood loss accurately predicts future detection of colorectal cancer. A prognostic model

OBJECTIVES

To examine the prognostic potential of repeated faecal haemoglobin (F-Hb) concentration measurements in faecal immunochemical test (FIT)-based screening for colorectal cancer (CRC).

DESIGN

Prognostic model.

SETTING

Dutch biennial FIT-based screening programme during 2014-2018.

PARTICIPANTS

265 881 participants completing three rounds of FIT, with negative test results (F-Hb <47 µg Hb/g faeces) in rounds 1 and 2.

INTERVENTIONS

Colonoscopy follow-up in participants with a positive FIT (F-Hb ≥47 µg Hb/g faeces).

MAIN OUTCOMES

We evaluated prognostic models for detecting advanced neoplasia (AN) and CRC in round 3, with as predictors, participant age, sex, F-Hb in rounds 1 and 2, and categories/combinations/non-linear transformations of F-Hb. Primary evaluation criteria included: risk prediction accuracy (calibration), discrimination of participants with versus without AN or CRC (optimism-adjusted C-statistics, range 0.5-1.0), the degree of risk stratification and C-statistics in external validation.

RESULTS

Among study participants, 8806 (3.3%) had a positive FIT result, 3254 (1.2%) had AN detected and 557 (0.2%) had cancer. F-Hb concentrations in rounds 1 and 2 were the strongest outcome predictors, with adjusted ORs of up to 9.4 (95% CI 7.5 to 11.7) for the highest F-Hb category. Risk predictions matched the observed risk for most participants (calibration intercept -0.008 to -0.099; slope 0.982-0.998), and discriminated participants with versus without AN or CRC with C-statistics of 0.78 (95% CI 0.77 to 0.79) and 0.73 (95% CI 0.71 to 0.75), respectively. The predicted risk ranged from 0.4% to 36.7% for AN and from 0.0% to 5.5% for CRC across participants. In external validation, the model retained similar discrimination accuracy for AN (C-statistic 0.77, 95% CI 0.66 to 0.87) and CRC (C-statistic 0.78, 95% CI 0.66 to 0.91).

CONCLUSION

Participants at lower versus higher risk of future AN or CRC can be accurately identified based on their age, sex and particularly, prior F-Hb concentrations. Risk stratification should be considered based on this information.

Serum Chloride and Admission Status Are Potential Prognostic Markers of High-Risk Polyps: A Prospective Characterization of Colorectal Polyps in a Tertiary Hospital in Saudi Arabia

Background: Colorectal cancer (CRC) is the most common cancer in men in Saudi Arabia. Other than age and family history, clinical and laboratory prognostic surrogates that may aid in streamlining and prioritization of screening colonoscopies are scarce. Through the examination of the local prevalence of advanced and malignant colorectal polyps, we hypothesized that the presence of certain clinical or laboratory parameters may signify an association with having high-risk polyps.

Methods: A prospective study over a period of one year starting on January 21, 2018 and involving all adult patients undergoing colonoscopy at King Saud Medical City, Riyadh. Of the total 1,104 recruited patients, 717 were included. The patients were sub-grouped based on the presence or absence of polyps. Patients with polyps were further sub-grouped into high-risk or low-risk polyps. Comparisons between groups were performed using univariate, relative risks (RRs), and multivariate analyses.

Results: Our polyp detection rate was 34.7% and our adenoma detection rate was 21.3%. The prevalence of advanced adenoma was 15.2% and the prevalence of malignant polyps was 6.7%. Several prognostic markers were associated with high-risk polyps such as advanced age (RR = 1.35, 95% confidence interval [CI]: 1.03 to 1.78), male gender (RR = 1.18, 95% CI: 1.06 to 1.31), inpatient status (RR = 1.46, 95% CI: 1.04 to 2.21), and low serum chloride (RR = 1.89, 95% CI: 1.05 to 2.37). With multivariate analysis, the hazard ratios for inpatient status and hypochloremia were 1.67 (95% CI: 1.034 to 2.612) and 1.12 (95% CI: 1.011 to 1.265), respectively.

Conclusion: We report the prevalence of malignant colorectal polyps in Saudi Arabia which was not reported before. Two unique prognostic markers for high-risk polyps were identified, namely, inpatient status and hypochloremia.

Risk Factors for Colorectal Polyps and Cancer

Colorectal cancer (CRC) is a common malignancy in the U.S. and worldwide. Most CRC cases arise from precancerous adenomatous and serrated polyps. Established risk factors for conventional adenomas and CRC include age, male sex, family history, obesity and physical inactivity, and red meat intake. White race and tobacco and alcohol use are important risk factors for serrated polyps, which have a distinct risk factor profile compared to conventional adenomas. A history of abdominopelvic radiation, acromegaly, hereditary hemochromatosis, or prior ureterosigmoidostomy also increases CRC risk. Understanding these risk factors allows for targeted screening of high-risk groups to reduce CRC incidence.

AGA Clinical Practice Update on Approach to the Use of Noninvasive Colorectal Cancer Screening Options: Commentary

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update Commentary is to review the available evidence and provide expert advice regarding the approach to using noninvasive colorectal cancer (CRC) screening options, including evidence for their effectiveness, selection of individuals for whom these tests are appropriate, implications of a positive non-colonoscopy screening test, and opportunities to enhance the quality of noninvasive CRC screening programs. This Clinical Practice Update was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. This expert commentary reflects recently published studies in this field, as well as the experiences of the authors who are gastroenterologists with high-level expertise in CRC screening and prevention.

Designing a Predictive Model for Colorectal Neoplasia Diagnosis Based on Clinical and Laboratory Findings in Colonoscopy Candidate Patients

BACKGROUND

Health authorities have expanded two strategies to diminish CRC-related influence: CR screening and improve diagnostic process in symptomatic patients. The aim of the current study is to design a predictive model to identify the most important risk factors that can efficiently predict patients who have high risk of colorectal neoplasia.

METHOD

A cross-sectional study was constructed to include all patients who had positive test for FIT or had one or more risk factors for colorectal cancer based on the guidelines of detecting high-risk groups for colorectal cancer in Iran. Multivariable binary logistic regression model was constructed for prediction of colorectal neoplasia. We used sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratio to check the accuracy. The Hosmer-Lemeshow test, chi-square test, and p value were used to determine the precision of model.

RESULT

Following an AIC stepwise selection model, only nine potential variables, namely gender, watery diarrhea, IBD, abdominal pain, melena, body mass index, depression drug, anti-inflammatory drug, and age, were found to be a predictor of colorectal neoplasia. The best cut-point probability in the final model was 0.27 and results of sensitivity and specificity, based on maximizing these two criteria, were 66% and 62%, respectively.

CONCLUSION

Overall, our model prediction was comparable with other risk prediction models for colorectal cancer. It had a modest discriminatory power to distinguish an individual's neoplasia colorectal risk.

New scoring systems for predicting advanced proximal neoplasia in asymptomatic adults with or without knowing distal colorectal findings: a prospective, cross-sectional study

BACKGROUND

Models estimating risk for advanced proximal colorectal neoplasia (APN) may be used to select colorectal cancer (CRC) screening test, either prior to knowing distal colorectal findings or afterward. Current models have only fair discrimination and nearly all require knowing distal findings.

OBJECTIVE

Derive and test risk prediction models for APN with and without distal findings.

SETTING

Selected endoscopy centers within central Indiana, USA.

PARTICIPANTS

Average-risk persons undergoing first-time screening colonoscopy.

INTERVENTIONS

Demographics, personal and family medical history, lifestyle factors and physical measures were linked to the most advanced finding in proximal and distal colorectal segments. For both models, logistic regression identified factors independently associated with APN on a derivation set. Based on equation coefficients, points were assigned to each factor, and risk for APN was examined for each score. Scores with comparable risks were collapsed into risk categories. Both models and their scoring systems were tested on the validation set.

MAIN OUTCOME

APN, defined as any adenoma or sessile serrated lesion ≥1 cm, one with villous histology or high-grade dysplasia, or CRC proximal to the descending colon.

RESULTS

Among 3025 subjects in the derivation set (mean age 57.3 ± 6.5 years; 52% women), APN prevalence was 4.5%; 2859 (94.5%) had complete data on risk factors. Independently associated with APN were age, sex, cigarette smoking, cohabitation status, metabolic syndrome, non-steroidal anti-inflammatory drug use and physical activity. This model (without distal findings) was well-calibrated (P = 0.62) and had good discrimination (c-statistic = 0.73). In low-, intermediate- and high-risk groups that comprised 21, 58 and 21% of the sample, respectively, APN risks were 1.47% (95% CI, 0.67-2.77%), 3.09% (CI, 2.31-4.04%) and 11.6% (CI, 9.10-14.4%), respectively (P < 0.0001), with no proximal CRCs in the low-risk group and 2 in the intermediate-risk group. When tested in the validation set of 1455, the model retained good metrics (calibration P = 0.85; c-statistic = 0.83), with APN risks in low- (22%), intermediate- (56%) and high-risk (22%) subgroups of 0.62% (CI, 0.08-2.23%) 2.20% (CI, 1.31-3.46%) and 13.0% (CI, 9.50-17.2%), respectively (P < 0.0001). There were no proximal CRCs in the low-risk group, and two in the intermediate-risk group. The model with distal findings performed comparably, with validation set metrics of 0.18 for calibration, 0.76 for discrimination and APN risk (% sample) in low-, intermediate-, and high-risk groups of 1.1 (69%), 8.3 (22%) and 22.3% (9%).

CONCLUSION

These models stratify large proportions of average-risk persons into clinically meaningful risk groups, and could improve screening efficiency, particularly for noncolonoscopy-based programs.

Derivation and validation of a predictive model for advanced colorectal neoplasia in asymptomatic adults

OBJECTIVE

Knowing risk for advanced colorectal neoplasia (AN) could help patients and providers choose among screening tests, improving screening efficiency and uptake. We created a risk prediction model for AN to help decide which test might be preferred, a use not considered for existing models.

DESIGN

Average-risk 50-to-80-year olds undergoing first-time screening colonoscopy were recruited from endoscopy units in Indiana. We measured sociodemographic and physical features, medical and family history and lifestyle factors and linked these to the most advanced finding. We derived a risk equation on two-thirds of the sample and assigned points to each variable to create a risk score. Scores with comparable risks were collapsed into risk categories. The model and score were tested on the remaining sample.

RESULTS

Among 3025 subjects in the derivation set (mean age 57.3 (6.5) years; 52% women), AN prevalence was 9.4%. The 13-variable model (c-statistic=0.77) produced three risk groups with AN risks of 1.5% (95% CI 0.72% to 2.74%), 7.06% (CI 5.89% to 8.38%) and 27.26% (CI 23.47% to 31.30%) in low-risk, intermediate-risk and high-risk groups (p value <0.001), containing 23%, 59% and 18% of subjects, respectively. In the validation set of 1475 subjects (AN prevalence of 8.4%), model performance was comparable (c-statistic=0.78), with AN risks of 2.73% (CI 1.25% to 5.11%), 5.57% (CI 4.12% to 7.34%) and 25.79% (CI 20.51% to 31.66%) in low-risk, intermediate-risk and high-risk subgroups, respectively (p<0.001), containing proportions of 23%, 59% and 18%.

CONCLUSION

Among average-risk persons, this model estimates AN risk with high discrimination, identifying a lower risk subgroup that may be screened non-invasively and a higher risk subgroup for which colonoscopy may be preferred. The model could help guide patient-provider discussions of screening options, may increase screening adherence and conserve colonoscopy resources.

Randomized Controlled Trial of Personalized Colorectal Cancer Risk Assessment vs Education to Promote Screening Uptake

INTRODUCTION

Risk stratification has been proposed as a strategy to improve participation in colorectal cancer (CRC) screening, but evidence is lacking. We performed a randomized controlled trial of risk stratification using the National Cancer Institute's Colorectal Cancer Risk Assessment Tool (CCRAT) on screening intent and completion.

METHODS

A total of 230 primary care patients eligible for first-time CRC screening were randomized to risk assessment via CCRAT or education control. Follow-up of screening intent and completion was performed by record review and phone at 6 and 12 months. We analyzed change in intent after intervention, time to screening, overall screening completion rates, and screening completion by CCRAT risk score tertile.

RESULTS

Of the patients, 61.7% of patients were aged <60 years, 58.7% female, and 94.3% with college or higher education. Time to screening did not differ between arms (hazard ratio 0.78 [95% confidence interval (CI) 0.52-1.18], P = 0.24). At 12 months, screening completion was 38.6% with CCRAT vs 44.0% with education (odds ratio [OR] 0.80 [95% CI 0.47-1.37], P = 0.41). Changes in screening intent did not differ between the risk assessment and education arms (precontemplation to contemplation: OR 1.52 [95% CI 0.81-2.86], P = 0.19; contemplation to precontemplation: OR 1.93 [95% CI 0.45-8.34], P = 0.38). There were higher screening completion rates at 12 months in the top CCRAT risk tertile (52.6%) vs the bottom (32.4%) and middle (31.6%) tertiles (P = 0.10).

DISCUSSION

CCRAT risk assessment did not increase screening participation or intent. Risk stratification might motivate persons classified as higher CRC risk to complete screening, but unintentionally discourage screening among persons not identified as higher risk.

AGA White Paper: Roadmap for the Future of Colorectal Cancer Screening in the United States

The American Gastroenterological Association's Center for Gastrointestinal Innovation and Technology convened a consensus conference in December 2018, entitled, "Colorectal Cancer Screening and Surveillance: Role of Emerging Technology and Innovation to Improve Outcomes." The goal of the conference, which attracted more than 60 experts in screening and related disciplines, including the authors, was to envision a future in which colorectal cancer (CRC) screening and surveillance are optimized, and to identify barriers to achieving that future. This White Paper originates from that meeting and delineates the priorities and steps needed to improve CRC outcomes, with the goal of minimizing CRC morbidity and mortality. A one-size-fits-all approach to CRC screening has not and is unlikely to result in increased screening uptake or desired outcomes owing to barriers stemming from behavioral, cultural, and socioeconomic causes, especially when combined with inefficiencies in deployment of screening technologies. Overcoming these barriers will require the following: efficient utilization of multiple screening modalities to achieve increased uptake; continued development of noninvasive screening tests, with iterative reassessments of how best to integrate new technologies; and improved personal risk assessment to better risk-stratify patients for appropriate screening testing paradigms.

Risk prediction rule for advanced neoplasia on screening colonoscopy for average-risk individuals

BACKGROUND

In resource-limited countries, risk stratification can be used to optimize colorectal cancer screening. Few prospective risk prediction models exist for advanced neoplasia (AN) in true average-risk individuals.

AIM

To create and internally validate a risk prediction model for detection of AN in average-risk individuals.

METHODS

Prospective study of asymptomatic individuals undergoing first screening colonoscopy. Detailed characteristics including diet, exercise and medications were collected. Multivariate logistic regression was used to elucidate risk factors for AN (adenoma ≥1 cm, villous histology, high-grade dysplasia or carcinoma). The model was validated through bootstrapping, and discrimination and calibration of the model were assessed.

RESULTS

980 consecutive individuals (51% F; 49% M) were enrolled. Adenoma and AN detection rates were 36.6% (F 29%: M 45%; P < 0.001) and 5.1% (F 3.8%; M 6.5%) respectively. On multivariate analysis, predictors of AN [OR (95%CI)] were age [1.036 (1.00-1.07); P = 0.048], BMI [overweight 2.21 (0.98-5.00); obese 3.54 (1.48-8.50); P = 0.018], smoking [< 40 pack-years 2.01 (1.01-4.01); ≥ 40 pack-years 3.96 (1.86-8.42); P = 0.002], and daily red meat consumption [2.02 (0.92-4.42) P = 0.079]. Nomograms of AN risk were developed in terms of risk factors and age separately for normal, overweight and obese individuals. The model had good discrimination and calibration.

CONCLUSION

The prevalence of adenoma and AN in average-risk Lebanese individuals is similar to the West. Age, smoking, and BMI are important predictors of AN, with obesity being particularly powerful. Though external validation is needed, this model provides an important platform for improved risk-stratification for screening programs in regions where universal screening is not currently employed.

Risk Stratification Strategies for Colorectal Cancer Screening: From Logistic Regression to Artificial Intelligence

Risk stratification is a system by which clinically meaningful separation of risk is achieved in a group of otherwise similar persons. Although parametric logistic regression dominates risk prediction, use of nonparametric and semiparametric methods, including artificial neural networks, is increasing. These statistical-learning and machine-learning methods, along with simple rules, are collectively referred to as "artificial intelligence" (AI). AI requires knowledge of study validity, understanding of model metrics, and determination of whether and to what extent the model can and should be applied to the patient or population under consideration. Further investigation is needed, especially in model validation and impact assessment.

Global Prevalence of Colorectal Neoplasia: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Most colorectal cancers (CRC) arise from colorectal adenomas, yet there is not enough information on global prevalence to inform health care policy. We examined the prevalence of any type of adenomas, advanced adenomas (AADs), and CRC according to age, sex, ethnicity, geographic regions, and anatomic location (proximal vs distal).

METHODS

MEDLINE and Embase were searched from their inception through May 1, 2018, to identify population-based, observational studies that reported the prevalence of colorectal neoplasia. Studies on participants 15 years or older, with a sample size of 500 persons or more, were included. Metaprop (College Station, TX) was used to model within-study variability by binomial distribution and Freeman-Tukey Double Arcsine Transformation to stabilize the variances. The prevalence figures were presented by proportions and their 95% CIs using random-effects models.

RESULTS

Our meta-analysis included 70 studies involving 637,414 individuals. The overall prevalence rates of adenoma (23.9%; 95% CI, 22.2%-25.8%), AAD (4.6%; 95% CI, 3.8%-5.5%), and CRC (0.4%, 95% CI, 0.3%-0.5%) were calculated. Subgroup analysis indicated that prevalence values (adenomas, AADs, and CRCs) were higher among men (29.7%, 6.5%, and 0.8%, respectively) than women (19.3%, 3.8% and 0.4%, respectively), among older adults (25.9%, 5.2%, and 0.6%, respectively) than younger adults (14.6%, 1.6%, and 0.1%, respectively), among Caucasians (23.7%, 6.6%, and 0.5%, respectively) than other ethnicities, in European countries (25.9%, 8.4%, and 0.8%, respectively) than other countries, and among patients with proximal (25.9%, 5.3%, and 0.1%, respectively) vs distal neoplasia.

CONCLUSIONS

In a systematic review and meta-analysis, we found a high prevalence of colorectal neoplasia among some populations. This indicates a need to expand CRC screening programs for these groups. The pooled prevalence estimates can be used as quality indicators for established CRC screening programs.

Colorectal sessile serrated lesion with large size or synchronous neoplasm: a prospective study

BACKGROUND

Colorectal sessile serrated lesion (SSL) with synchronous neoplasm or large size are linked to higher risk of cancer, but their characteristics are unclear.

METHODS

We prospectively included consecutive colorectal hyperplasic polyp and SSL collected at our institution from August 2011 to August 2012. The following data were collected and analyzed: age, gender, polyp site, aggregated polyp size, history of polyp, and synchronous neoplasm.

RESULTS

We collected 437 specimens including 353 (80.8%) hyperplasic polyp and 84 (19.2%) SSL. Compared with hyperplasic polyp, SSL was independently associated with proximal colon [odds ratio (OR) 3.61, P< 0.001], larger size (OR 3.98, P< 0.001), but not history of polyp, age or gender. Large SSL (≥1 vs <1 cm) was associated with polyp site (P= 0.035) and synchronous advanced adenoma and cancer (P< 0.001). SSL with synchronous adenoma and cancer were more likely found in males (OR 1.91, P= 0.001), elderly (OR 1.02, P= 0.033), and patients with the index polyp in proximal colon (OR 1.32, P= 0.022), but not related to history of adenoma and cancer. Moreover, synchronous adenoma, SSL and cancer were independently associated with male gender (OR 1.90, P< 0.001), but surprisingly not older age, histology of index polyp (SSL vs hyperplasic polyp), index-polyp site or history of adenoma and cancer.

CONCLUSIONS

This prospective study shows male gender is associated with both synchronous adenoma and cancer, and synchronous adenoma, SSL and cancer, while index polyp site is associated with synchronous adenoma and cancer.

Clinical and Economic Impact of Tailoring Screening to Predicted Colorectal Cancer Risk: A Decision Analytic Modeling Study

BACKGROUND

Global increases in colorectal cancer risk have spurred debate about optimal use of screening resources. We explored the potential clinical and economic impact of colorectal cancer screening tailored to predicted colorectal cancer risk.

METHODS

We compared screening tailored to predicted risk versus uniform screening in a validated decision analytic model, considering the average risk population's actual colorectal cancer risk distribution, and a risk-prediction tool's discriminatory ability and cost. Low, moderate, and high risk tiers were identified as colorectal cancer risk after age 50 years of ≤3%, >3 to <12%, and ≥12%, respectively, based on threshold analyses with willingness-to-pay <$50,000/quality-adjusted life-year (QALY) gained. Tailored colonoscopy (once at age 60 years for low risk, every 10 years for moderate risk, and every 5 years for high risk) was compared with colonoscopy every 10 years for all. Tailored fecal immunochemical testing (FIT)/colonoscopy (annual FIT for low and moderate risk, colonoscopy every 5 years for high risk) was compared with annual FIT for all.

RESULTS

Assuming no colorectal cancer risk misclassification or risk-prediction tool costs, tailored screening was preferred over uniform screening. Tailored colonoscopy was minimally less effective than uniform colonoscopy, but saved $90,200-$889,000/QALY; tailored FIT/colonoscopy yielded more QALYs/person than annual FIT at $10,600-$60,000/QALY gained. Relatively modest colorectal cancer risk misclassification rates or risk-prediction tool costs resulted in uniform screening as the preferred approach.

CONCLUSIONS

Current risk-prediction tools may not yet be accurate enough to optimize colorectal cancer screening.

IMPACT

Uniform screening is likely to be preferred over tailored screening if a risk-prediction tool is associated with even modest misclassification rates or costs.

Advanced neoplasia in Veterans at screening colonoscopy using the National Cancer Institute Risk Assessment Tool

BACKGROUND

Adapting screening strategy to colorectal cancer (CRC) risk may improve efficiency for all stakeholders however limited tools for such risk stratification exist. Colorectal cancers usually evolve from advanced neoplasms that are present for years. We applied the National Cancer Institute (NCI) CRC Risk Assessment Tool, which calculates future risk of CRC, to determine whether it could be used to predict current advanced neoplasia (AN) in a veteran cohort undergoing a baseline screening colonoscopy.

METHODS

This was a prospective assessment of the relationship between future CRC risk predicted by the NCI tool, and the presence of AN at screening colonoscopy. Family, medical, dietary and physical activity histories were collected at the time of screening colonoscopy and used to calculate absolute CRC risk at 5, 10 and 20 years. Discriminatory accuracy was assessed.

RESULTS

Of 3121 veterans undergoing screening colonoscopy, 94% had complete data available to calculate risk (N = 2934, median age 63 years, 100% men, and 15% minorities). Prevalence of AN at baseline screening colonoscopy was 11 % (N = 313). For tertiles of estimated absolute CRC risk at 5 years, AN prevalences were 6.54% (95% CI, 4.99, 8.09), 11.26% (95% CI, 9.28-13.24), and 14.21% (95% CI, 12.02-16.40). For tertiles of estimated risk at 10 years, the prevalences were 6.34% (95% CI, 4.81-7.87), 11.25% (95% CI, 9.27-13.23), and 14.42% (95% CI, 12.22-16.62). For tertiles of estimated absolute CRC risk at 20 years, current AN prevalences were 7.54% (95% CI, 5.75-9.33), 10.53% (95% CI, 8.45-12.61), and 12.44% (95% CI, 10.2-14.68). The area under the curve for predicting current AN was 0.60 (95% CI; 0.57-0.63, p < 0.0001) at 5 years, 0.60 (95% CI, 0.57-0.63, p < 0.0001) at 10 years and 0.58 (95% CI, 0.54-0.61, p < 0.0001) at 20 years.

CONCLUSION

The NCI tool had modest discriminatory function for estimating the presence of current advanced neoplasia in veterans undergoing a first screening colonoscopy. These findings are comparable to other clinically utilized cancer risk prediction models and may be used to inform the benefit-risk assessment of screening, particularly for patients with competing comorbidities and lower risk, for whom a non-invasive screening approach is preferred.

Risk Scores for Predicting Advanced Colorectal Neoplasia in the Average-risk Population: A Systematic Review and Meta-analysis

OBJECTIVES

A systematic review and meta-analysis was performed to summarize the available evidence on risk scores for predicting advanced colorectal neoplasia (advanced adenomas and cancer) in average-risk and asymptomatic populations undergoing screening colonoscopy.

METHODS

PubMed, EMBASE, and Web of Science databases were searched up to 28 March 2018. Studies that developed or validated a risk score to predict the risk of advanced colorectal neoplasia were included. Two reviewers independently extracted study characteristics including diagnostic performance indicators and assessed risk of bias and applicability in the included studies. Meta-analyses were conducted to determine the overall discrimination of risk scores evaluated by more than 1 study.

RESULTS

A total of 22 studies including 17 original risk scores were identified. Risk scores included a median number of 5 risk factors. Factors most commonly included were age, sex, family history in first-degree relatives, body mass index and smoking. The area under the receiver operating characteristic curve of risk scores ranged from 0.62 to 0.77 in the individual studies and from 0.61 to 0.70 in the meta-analyses.

CONCLUSIONS

Although the majority of available risk scores had relatively weak discriminatory power, they may be of some use for risk stratification in CRC screening. Rather than developing more risk scores based on environmental risk factors, future research should focus on exploring possibilities of enhancing predictive power by combining risk factor data with novel laboratory matters, such as polygenetic risk scores.

Precision Medicine Versus Population Medicine in Colon Cancer: From Prospects of Prevention, Adjuvant Chemotherapy, and Surveillance

With the advances of technologic revolution that provides new insights into human biology, genetics and cancer, as well as advantages of big data which amasses large amounts of information for us to approach cancer treatment and prevention, we are facing challenges of organically combining data from studies based on general population and information from individual testing and setting out precisional recommendations in cancer diagnosis, prevention, and treatment. We are obligated to accelerate the adaptation of new scientific discoveries into effective treatments and prevention for cancer. In this review, we introduce our opinions on bringing knowledge of precision and population medicine together to guide our clinical practice from the prospects of colorectal cancer prevention, stage III colon cancer adjuvant therapy, and postsurgery surveillance.

Long-term outcomes of endoscopic submucosal dissection for high-grade dysplasia and early-stage carcinoma in the colorectum

Background

Colorectal carcinomas (CRCs) arise from premalignant precursors in an adenoma-carcinoma sequence, in which adenoma with high-grade dysplasia (HGD) and early-stage carcinoma are defined as advanced neoplasia. A limited number of studies have evaluated the long-term outcomes of endoscopic submucosal dissection (ESD) for advanced colorectal neoplasia. This study aimed to assess the efficacy and safety of ESD for advanced colorectal neoplasia as well as the long-term outcomes, including local recurrence and metastasis.

Methods

We analyzed data collected from 610 consecutive patients with 616 advanced colorectal neoplasia lesions treated with ESD between January 2007 and December 2013. Clinical, endoscopic, and histological data were collected over a median follow-up period of 58 months to determine tumor stage and type, resection status, complications, tumor recurrence, and distant metastasis.

Results

The overall rates of en bloc resection, histological complete resection, and major complications were 94.3%, 89.4%, and 2.3%, respectively. Hybrid ESD was an independent factor of piecemeal resection. Tumor location in the colon was associated with increased risk of ESD-related complications. During the follow-up period, all patients remained free of metastasis. However, local recurrence occurred in 4 patients (0.8%); piecemeal resection was a risk factor.

Conclusions

ESD is effective and safe for resection of advanced colorectal neoplasia, with a high en bloc resection rate and favorable long-term outcomes. ESD is indicated for the treatment of HGD and early-stage CRC to obtain curative resection and reduce local recurrence rate.