A combination of clinical risk stratification and fecal immunochemical test is useful for identifying persons with high priority of early colonoscopy

Combined performance of fecal immunochemical tests and a genetic risk score for advanced neoplasia detection

Fecal immunochemical tests (FITs) are increasingly used as noninvasive screening tests in colorectal cancer (CRC) screening programs. Polygenic risk scores (PRS) are increasingly propagated for risk stratification in CRC screening. We aimed to assess the potential of combining FIT results and PRS to enhance diagnostic accuracy of detecting advanced neoplasia (AN) compared to using FIT results alone. Of 10,362 participants of screening colonoscopy in Southern Germany who conducted either one of two quantitative FITs, genotyping was done in all participants with advanced neoplasia (CRC or advanced adenoma) and a random subset of controls. Among 5,306 individuals, a PRS was calculated based on the number of risk alleles in 140 single nucleotide polymorphisms. Partial areas under the receiver operating characteristics (ROC) curves (pAUCs) were computed for FIT and PRS alone and combined, focusing on a specificity range of 100%-80%. Both FITs showed similar performance characteristics with pAUCs (95%CIs) of 0.661 (0.625-0.698) (Ridascreen Hemoglobin) and 0.682 (0.661-0.701) (FOB Gold) for AN detection. PRS alone reached a pAUC (95%CI) of 0.524 (0.499-0.550) and 0.530 (0.516-0.545), respectively, and its addition to FIT did not improve pAUCs (0.659 (0.622-0.697) and 0.667 (0.650-0.687), respectively). This finding was confirmed by investigating sensitivities at fixed specificities at 85%, 90% and 95%. Partial AUCs also did not improve when adding the weighted PRS to FIT instead of the unweighted PRS. In summary, the combination with PRS did not improve diagnostic accuracy of FIT-based screening in a large asymptomatic CRC screening population from South-Western Germany.

A scoping review of risk-stratified bowel screening: current evidence, future directions

PURPOSE

In this scoping review, we examined the international literature on risk-stratified bowel screening to develop recommendations for future research, practice and policy.

METHODS

Six electronic databases were searched from inception to 18 October 2021: Medline, Embase, PsycINFO, CINAHL, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials. Forward and backwards citation searches were also undertaken. All relevant literature were included.

RESULTS

After de-deduplication, 3,629 records remained. 3,416 were excluded at the title/abstract screening stage. A further 111 were excluded at full-text screening stage. In total, 102 unique studies were included. Results showed that risk-stratified bowel screening programmes can potentially improve diagnostic performance, but there is a lack of information on longer-term outcomes. Risk models do appear to show promise in refining existing risk stratification guidelines but most were not externally validated and less than half achieved good discriminatory power. Risk assessment tools in primary care have the potential for high levels of acceptability and uptake, and therefore, could form an important component of future risk-stratified bowel screening programmes, but sometimes the screening recommendations were not adhered to by the patient or healthcare provider. The review identified important knowledge gaps, most notably in the area of organisation of screening services due to few pilots, and what risk stratification might mean for inequalities.

CONCLUSION

We recommend that future research focuses on what organisational challenges risk-stratified bowel screening may face and a consideration of inequalities in any changes to organised bowel screening programmes.

Factors associated with adherence to colonoscopy among individuals who were positive in the preliminary screening for colorectal neoplasms

OBJECTIVES

This study aimed to investigate the potential factors associated with adherence to colonoscopy among participants who were preliminarily screened positive in a community-based colorectal cancer screening program in China.

METHODS

This study analyzed data from 1219 out of 6971 community residents who were identified as positive cases by the well-validated high-risk factor questionnaire (HRFQ) or fecal immunochemical test (FIT) in the preliminary screening stage for colorectal neoplasms. Patients showing adherence to colonoscopy were defined as those who received positive results in a preliminary screening for colorectal neoplasms and later received a colonoscopy examination as required. The associations of social-demographic factors, lifestyle behaviors, history of diabetes, body mass index (BMI), and risk factors in the HRFQ with adherence to colonoscopy were evaluated using logistic regression models.

RESULTS

Among 1219 participants who preliminarily screened positive, the top five risk factors reported by the participants were chronic constipation (25.9%), hematochezia (23.5%), family history of CRC in first-degree relatives (22.1%), chronic diarrhea (21.8%), and history of polyps (16.6%). Around 14.2% of participants who preliminarily screened positive reported three or more risk factors, and the proportion was 26.2% among participants who were positive according to both HRFQ and FIT. Among all participants who were preliminarily screened positive, the multivariable results showed that those who were married (OR = 1.58, 95% CI: 1.12, 2.25, p = 0.01), had chronic diarrhea (OR = 1.34, 95% CI: 1.00, 1.78, p = 0.047), and had a positive FIT (OR = 1.60, 95% CI: 1.21, 2.10, p < 0.001 for patients who were negative according to HRFQ but positive according to FIT; OR = 2.12, 95% CI: 1.33, 2.78, p = 0.002 for patients who were positive for both HRFQ and FIT) were more likely to adhere to colonoscopy, while participants with a history of cancer (OR: 0.50, 95% CI: 0.31, 0.79, p = 0.003) were less likely to adhere to colonoscopy. The results among participants who were tested positive according to only HRFQ were similar to those among all participants who were tested positive according to HRFQ or FIT. However, among participants who were tested positive according to only FIT, we only found that those who were married (OR = 2.52, 95% CI: 1.08, 5.90, p = 0.033) had a higher odds of adhering to colonoscopy, while those with a history of diabetes (OR = 0.35, 95% CI: 0.13, 0.96, p = 0.042) were less likely to adhere to colonoscopy.

CONCLUSION

Our findings provide evidence supporting the development of tailored interventional strategies that aim to improve adherence to colonoscopy for individuals with a high risk of colorectal neoplasms. Both barriers and facilitators associated with adherence to colonoscopy should be considered in supportive systems and health policies. However, further well-designed prospective studies are warranted to confirm our findings.

Comparison of multiple statistical models for the development of clinical prediction scores to detect advanced colorectal neoplasms in asymptomatic Thai patients

A good clinical prediction score can help in the risk stratification of patients with colorectal cancer (CRC) undergoing colonoscopy screening. The aim of our study was to compare model performance of binary logistic regression (BLR), polytomous logistic regression (PLR), and classification and regression tree (CART) between the clinical prediction scores of advanced colorectal neoplasia (ACN) in asymptomatic Thai patients.We conducted a cross-sectional study of 1311 asymptomatic Thai patients to develop a clinical prediction model. The possible predictive variables included sex, age, body mass index, family history of CRC in first-degree relatives, smoking, diabetes mellitus, and the fecal immunochemical test in the univariate analysis. Variables with a P value of .1 were included in the multivariable analysis, using the BLR, CART, and PLR models. Model performance, including the area under the receiver operator characteristic curve (AUROC), was compared between the model types.ACN was diagnosed in 53 patients (4.04%). The AUROCs were not significantly different between the BLR and CART models for ACN prediction with an AUROC of 0.774 (95% confidence interval [95% CI]: 0.706-0.842) and 0.765 (95% CI: 0.698-0.832), respectively (P = .712). A significant difference was observed between the PLR and CART models in predicting average to moderate ACN risk with an AUROC of 0.767 (95% CI: 0.695-0.839 vs AUROC 0.675 [95% CI: 0.599-0.751], respectively; P = .009).The BLR and CART models yielded similar accuracies for the prediction of ACN in Thai patients. The PLR model provided higher accuracy for ACN prediction than the CART model.

Risk Stratification Score Improves Sensitivity for Advanced Colorectal Neoplasia in Colorectal Cancer Screening: The Oshima Study Workgroup

INTRODUCTION

Noninvasive colorectal cancer (CRC) screening methods with higher sensitivity for advanced colorectal neoplasia (ACN) than the fecal immunochemical test (FIT) alone are warranted. This study aimed to elucidate the diagnostic performance of a risk stratification score calculated using baseline individual characteristics and its combination with FIT for detecting ACN.

METHODS

This cross-sectional analysis of data from a prospective cohort in Izu Oshima, Japan, included asymptomatic individuals age 40-79 years who underwent both 2-day quantitative FIT and screening colonoscopy. The 8-point risk score, calculated based on age, sex, CRC family history, body mass index, and smoking history, was assessed. Colonoscopy results were used as reference.

RESULTS

Overall, 1,191 individuals were included, and 112 had ACN. The sensitivity and specificity of the 1-/2-day FIT (cutoff: 50-200 ng Hb/mL) for ACN were 17.9%-33.9% (4.9%-22.0% for right-sided ACN) and 91.8%-97.6%, respectively. The risk score's c-statistic for ACN was 0.66, and combining the score (cutoff: 5 points) with 1-/2-day FIT (cutoff: 50-200 ng Hb/mL) yielded a sensitivity and specificity for ACN of 46.4%-56.3% (43.9%-48.8% for right-sided ACN) and 76.6%-80.8%, respectively. The specificity of the risk score and FIT combination for all adenomatous lesions was 82.4%-86.4%.

DISCUSSION

The 8-point risk score remarkably increased the sensitivity for ACN, particularly for right-sided ACN. Although the specificity decreased, it was still maintained at a relatively high level. The risk score and FIT combination has the potential to become a viable noninvasive CRC screening option.

The use of electronic healthcare records for colorectal cancer screening referral decisions and risk prediction model development

BACKGROUND

The database used for the NHS Bowel Cancer Screening Programme (BCSP) derives participant information from primary care records. Combining predictors with FOBTs has shown to improve referral decisions and accuracy. The richer data available from GP databases could be used to complement screening referral decisions by identifying those at greatest risk of colorectal cancer. We determined the availability of data for key predictors and whether this information could be used to inform more accurate screening referral decisions.

METHODS

An English BCSP cohort was derived using the electronic notifications received from the BCSP database to GP records. The cohort covered a period between 13th May 2009 to 17th January 2017. Completeness of variables and univariable associations were assessed. Risk prediction models were developed using Cox regression and multivariable fractional polynomials with backwards elimination. Optimism adjusted performance metrics were reported. The sensitivity and specificity of a combined approach using the negative FOBT model plus FOBT positive patients was determined using a probability equivalent to a 3% PPV NICE guidelines level.

RESULTS

292,059 participants aged 60-74 were derived for the BCSP screening cohort. A model including the screening test result had a C-statistic of 0.860, c-slope of 0.997, and R² of 0.597. A model developed for negative screening results only had a C-statistic of 0.597, c-slope of 0.940, and R² of 0.062. Risk predictors included in the models included; age, sex, alcohol consumption, IBS diagnosis, family history of gastrointestinal cancer, smoking status, previous negatives and whether a GP had ordered a blood test. For the combined screening approach, sensitivity increased slightly from 53.90% (FOBT only) to 58.82% but at the expense of an increased referral rate.

CONCLUSIONS

This research has identified several potential predictors for CRC in a BCSP population. A risk prediction model developed for BCSP FOBT negative patients was not clinically useful due to a low sensitivity and increased referral rate. The predictors identified in this study should be investigated in a refined algorithm combining the quantitative FIT result. Combining data from multiple sources enables fuller patient profiles using the primary care and screening database interface.

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.

Towards risk-stratified colorectal cancer screening. Adding risk factors to the fecal immunochemical test: Evidence, evolution and expectations

With increasing incidence and mortality, colorectal cancer (CRC) is a growing health problem worldwide. An effective way to address CRC is by screening for fecal (occult) blood by the fecal immunochemical test (FIT). However, there is room for improvement since precursor lesions and CRC bleed intermittent and can therefore be missed by the FIT (false negatives) or, the detected blood did not result from precursor lesions or CRC (false positives). This review provides the latest evidence on risk prediction models using FIT combined with additional risk factors before colonoscopy, which risk factors to include and if these models will better discriminate between normal findings and CRC compared to the FIT-only. Many prediction models are known for CRC, but compared to the FIT, these are less effective in detecting CRC. The literature search resulted in 645 titles where 11 papers matched the inclusion criteria and were analyzed. Comparing the FIT-only with the risk prediction models for detecting CRC resulted in a significantly increased discrimination for the models. In addition, 2 different risk-stratification categories before colonoscopy were distinguished, namely the 1-model approach which combined risk factors with FIT results in a prediction model while the 2 step approach used risk factors apart from the FIT. Finally, combining FIT with CRC risk factors by means of a model before colonoscopy seems effective regarding discriminative power, however, more research is needed for validation combined with transparent and standardized reporting to improve quality assessment, for which suggestions are reported in this study.

Comparative evaluation of novel screening strategies for colorectal cancer screening in China (TARGET-C): a study protocol for a multicentre randomised controlled trial

INTRODUCTION

Screening for colorectal cancer (CRC) is effective in reducing the disease burden. However, high-level evidence from randomised controlled trials on the effectiveness of CRC screening modalities is still lacking. We will conduct a large-scale multicentre randomised controlled trial in China to evaluate the effectiveness and cost-effectiveness of different CRC screening strategies.

METHODS AND ANALYSIS

20 000 eligible participants aged 50-74 years are enrolled in five provinces in China. After providing signed informed consent, the participants will be randomised into one of the three screening groups: (1) one-time colonoscopy (n=4000), (2) annual faecal immunochemical test (FIT) (n=8000) and (3) annual risk-adapted screening strategy (n=8000). The risk-adapted screening strategy will use an established CRC risk scoring system, the Asia-Pacific Colorectal Screening score. Participants at high risk of CRC will be referred for colonoscopy, while participants at low risk will be referred for an FIT. Information on clinical reports, epidemiological risk factors and health economic factors will be collected and stored in a web-based data management system. We will further request the participants to donate blood, faecal and saliva samples before conducting the colonoscopy. The primary outcome will be the detection rate of advanced colorectal neoplasia and the secondary outcomes will include the rates of CRC-related mortality, incidence of CRC, participation and complications. The study will last for at least 4 years and the cohort will be followed for 10 years to adequately answer the scientific questions.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of the National Cancer Center/Cancer Hospital, the Chinese Academy of Medical Sciences and Peking Union Medical College (18-013/1615). The results of the study will be submitted for publication in peer-reviewed journals and will be discussed by policy and decision makers.

TRIAL REGISTRATION NUMBER

ChiCTR1800015506.