Use of colonoscopy as a primary screening test for colorectal cancer in average risk people

A Score to Predict Advanced Colorectal Neoplasia in Adults Younger than Age 45

BACKGROUND

Early-onset colorectal cancer (CRC) requires identifying adults at heightened risk of advanced colorectal neoplasia (AN) who may warrant colonoscopy initiation < age 45 years.

AIMS

We aim to develop and validate a model estimating the likelihood of AN in adults age < 45 years.

METHODS

We performed a cross-sectional analysis of adults' ages 18-44 years who underwent a colonoscopy between 2011 and 2021 at a tertiary center. Subjects with AN constituted the case group while those with a normal colonoscopy or non-advanced neoplasia (NAN) formed the control group. We used backward elimination multivariable logistic regression methods to construct a model based on significant associations (p < 0.05) between risk factors and the presence of AN in a randomly selected training set and confirmed the associations in a validation set.

RESULTS

AN was detected in 346 (3.7%) of the 9,446 participants included. The reduced logistic regression model based on the training set identified BMI (p = 0.0157), family history of CRC (first-degree relative < 60, p < 0.0001; other family history of CRC p = 0.0117), and tobacco use (current vs. never, p = 0.0015, former vs. never, p = 0.0009) as risk factors for AN. In the validation set, the model exhibited moderate discriminatory power (c-statistic 0.645). The prediction score estimated the likelihood of detecting AN in the complete dataset, from 1.8% for individuals scoring 1 to > 14% for individuals scoring ≥ 9.

CONCLUSION

We developed and internally validated a simple score using clinical factors which successfully predicts the likelihood of AN in adults < 45 years undergoing colonoscopy. Once externally validated, the proposed risk score may be useful for individualized CRC screening strategies.

An adjusted Asia-Pacific colorectal screening score system to predict advanced colorectal neoplasia in asymptomatic Chinese patients

PURPOSE

The Asia-Pacific Colorectal Screening (APCS) score and its derivatives have been used to predict advanced colorectal neoplasia (ACN). However, it remains unknown whether they apply to the current Chinese population in general clinical practice. Therefore, we aimed to update the APCS score system by applying data from two independent asymptomatic populations to predict the risk of ACN in China.

METHODS

We developed an adjusted APCS (A-APCS) score by using the data of asymptomatic Chinese patients undergoing colonoscopies from January 2014 to December 2018. Furthermore, we validated this system in another cohort of 812 patients who underwent screening colonoscopy between January and December 2021. The discriminative calibration ability of the A-APCS and APCS scores was comparatively evaluated.

RESULTS

Univariate and multivariate logistic regression were applied to assess the risk factors for ACN, and an adjusted scoring system of 0 to 6.5 points was schemed according to the results. Utilizing the developed score, 20.2%, 41.2%, and 38.6% of patients in the validation cohort were classified as average, moderate, and high risk, respectively. The corresponding ACN incidence rates were 1.2%, 6.0%, and 11.1%, respectively. In addition, the A-APCS score (c-statistics: 0.68 for the derivation and 0.80 for the validation cohort) showed better discriminative power than using predictors of APCS alone.

CONCLUSIONS

The A-APCS score may be simple and useful in clinical applications for predicting ACN risk in China.

External validation of models for predicting risk of colorectal cancer using the China Kadoorie Biobank

BACKGROUND

In China, colorectal cancer (CRC) incidence and mortality have been steadily increasing over the last decades. Risk models to predict incident CRC have been developed in various populations, but they have not been systematically externally validated in a Chinese population.  This study aimed to assess the performance of risk scores in predicting CRC using the China Kadoorie Biobank (CKB), one of the largest and geographically diverse prospective cohort studies in China.

METHODS

Nine models were externally validated in 512,415 participants in CKB and included 2976 cases of CRC. Model discrimination was assessed, overall and by sex, age, site, and geographic location, using the area under the receiver operating characteristic curve (AUC). Model discrimination of these nine models was compared to a model using age alone. Calibration was assessed for five models, and they were re-calibrated in CKB.

RESULTS

The three models with the highest discrimination (Ma (Cox model) AUC 0.70 [95% CI 0.69-0.71]; Aleksandrova 0.70 [0.69-0.71]; Hong 0.69 [0.67-0.71]) included the variables age, smoking, and alcohol. These models performed significantly better than using a model based on age alone (AUC of 0.65 [95% CI 0.64-0.66]). Model discrimination was generally higher in younger participants, males, urban environments, and for colon cancer. The two models (Guo and Chen) developed in Chinese populations did not perform better than the others. Among the 10% of participants with the highest risk, the three best performing models identified 24-26% of participants that went on to develop CRC.

CONCLUSIONS

Several risk models based on easily obtainable demographic and modifiable lifestyle factor have good discrimination in a Chinese population. The three best performing models have a higher discrimination than using a model based on age alone.

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.

Assessing Individual Risk for High-Risk Early Colorectal Neoplasm for Pre-Selection of Screening in Shanghai, China: A Population-Based Nested Case-Control Study

Objective

To identify people with high-risk early colorectal neoplasm is highly desirable for pre-selection in colorectal cancer (CRC) screening in low-resource countries. We aim to build and validate a risk-based model so as to improve compliance and increase the benefits of screening.

Patients and Methods

Using data from the Shanghai CRC screening cohort, we conducted a population-based nested case–control study to build a risk-based model. Cases of early colorectal neoplasm were extracted as colorectal adenomas and stage 0-I CRC. Each case was matched with five individuals without neoplasm (controls) by the screening site and year of enrollment. Cases and controls were then randomly divided into two groups, with two thirds for building the risk prediction model and the other one third for model validation. Known risk factors were included for risk prediction models using logistic regressions. The area under the receiver operating characteristic curve (AUC) and Hosmer–Lemeshow chi-square statistics were used to evaluate model discrimination and calibration. The predicted individual risk probability was calculated under the risk regression equation.

Results

The model incorporating age, sex, family history and lifestyle factors including body mass index (BMI), smoking status, alcohol, regular moderate-to-intensity physical activity showed good calibration and discrimination. When the risk cutoff threshold was defined as 17%, the sensitivity and specificity of the model were 63.99% and 53.82%, respectively. The validation data analysis also showed well discrimination.

Conclusion

A risk prediction model combining personal and lifestyle factors was developed and validated for high-risk early colorectal neoplasm among the Chinese population. This risk-based model could improve the pre-selection for screening and contribute a lot to efficient population-based screening in low-resource countries.

Proton-pump inhibitors are associated with a high false-positivity rate in faecal immunochemical testing

BACKGROUND

False-positivity rates in faecal immunochemical test (FIT) can be affected by drug exposure. We aimed to assess the association between proton pump inhibitors (PPI) consumption and false positive (FP) results in a colorectal cancer (CRC) screening programme using electronic prescription records.

METHODS

A retrospective cohort study within a population-based screening program for CRC from 2010 to 2016 was performed. Participants with a conclusive FIT result and with prescription electronic data were included. An FP result was defined as having a positive FIT (≥ 20 µg haemoglobin/g faeces) and a follow-up colonoscopy without intermediate or high-risk lesions or CRC. Screening data were anonymously linked to the public data analysis program for health research and innovation (PADRIS) database that recorded patient diseases history and reimbursed medication. PPI exposure was defined as having retrieved at least one dispensation of PPI three months prior to the FIT.

RESULTS

A total of 89,199 tests (of 46,783 participants) were analysed, 4824 (5.4%) tested positive and the proportion of FP was 53.5%. Overall, 17,544 participants (19.7%) were PPI users prior to FIT performance. PPI exposure increased the probability of obtaining an FP FIT result from 50.4 to 63.3% (adjusted OR 1.39; 95% CI 1.18-1.65). Nonsteroidal anti-inflammatory drugs, acetylsalicylic acid, antibiotics, and laxatives were also associated with an FP result. The effect of PPI was independent and showed a synergistic interaction with nonsteroidal anti-inflammatory drugs.

CONCLUSION

PPIs increase FIT positivity at the expense of FP results. The recommendation to avoid their use before FIT performance could reduce up to 3% of colonoscopies and 9% of FP results.

Liver transplant recipients have an increased risk of developing colorectal adenomas: Results from a retrospective study

BACKGROUND

Liver transplant recipients have an increased incidence of malignancies, but it is unclear whether they have a higher risk of colorectal cancer.

AIM

To investigate whether liver transplant recipients have an increased risk of developing colorectal adenomas (a surrogate marker of colorectal cancer risk).

PATIENTS AND METHODS

One hundred thirty-nine liver transplant recipients (excluding primary sclerosing cholangitis) who underwent a colonoscopy and polypectomy before and after transplantation, and 367 nontransplanted patients who underwent a colonoscopy for colorectal cancer screening and a second colonoscopy later were retrospectively studied. The risks of incident colorectal adenomas and high-risk adenomas (advanced or multiple adenomas or carcinomas) were compared between both cohorts.

RESULTS

Incident colorectal adenomas were found in 40.3% of the transplanted patients and 30.0% of the nontransplanted patients (15.1% and 5.5%, respectively, had high-risk adenomas). After adjusting for age, sex, presence of adenomas in the baseline endoscopy, and interval between colonoscopies, transplant recipients showed a higher risk of developing colorectal adenomas (OR: 1.61; 95% CI: 1.05-2.47; p = .03) and high-risk adenomas (OR: 2.87; 95% CI: 1.46-5.65; p = .002).

CONCLUSIONS

Our results suggest that liver transplant recipients have an increased risk of developing colorectal adenomas and lesions with high risk of colorectal cancer.

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.

Association of Cardiovascular Risk Assessment with Early Colorectal Neoplasia Detection in Asymptomatic Population: A Systematic Review and Meta-Analysis

Previous studies have shown a strong coexistence of colorectal neoplasia (CRN) and cardiovascular diseases (CVD). This study was aimed to summarize the available evidence on association of CVD risk with early CRN detection in asymptomatic populations. PubMed, Web of Science, and Embase were systematically searched for eligible studies published until Dec 20, 2019. Studies exploring the associations of recommended CVD risk assessment methods (e.g., risk scores, carotid artery plaque, and coronary artery calcium score [CACS]) with risk of CRN were included. Meta-analyses were conducted to determine the overall association of CVD risk with the CRN. A total of 12 studies were finally included. The association of carotid artery plaque with the risk of colorectal adenoma (AD) was weakest (pooled odds ratio [OR)] 1.27, 95% confidence interval [CI), 1.12, 1.45]. Participants with CACS>100 had about 2-fold increased risk of AD than those with CACS=0. The pooled ORs were 3.36 (95% CI, 2.15, 5.27) and 2.30 (95% CI, 1.69, 3.13) for the risk of advanced colorectal neoplasia (AN) and AD, respectively, in participants with Framingham risk score (FRS)>20%, when compared to participants at low risk (FRS<10%). FRS might help identify subgroups at increased risk for AN, but further studies are needed.

Robust Machine Learning for Colorectal Cancer Risk Prediction and Stratification

While colorectal cancer (CRC) is third in prevalence and mortality among cancers in the United States, there is no effective method to screen the general public for CRC risk. In this study, to identify an effective mass screening method for CRC risk, we evaluated seven supervised machine learning algorithms: linear discriminant analysis, support vector machine, naive Bayes, decision tree, random forest, logistic regression, and artificial neural network. Models were trained and cross-tested with the National Health Interview Survey (NHIS) and the Prostate, Lung, Colorectal, Ovarian Cancer Screening (PLCO) datasets. Six imputation methods were used to handle missing data: mean, Gaussian, Lorentzian, one-hot encoding, Gaussian expectation-maximization, and listwise deletion. Among all of the model configurations and imputation method combinations, the artificial neural network with expectation-maximization imputation emerged as the best, having a concordance of 0.70 ± 0.02, sensitivity of 0.63 ± 0.06, and specificity of 0.82 ± 0.04. In stratifying CRC risk in the NHIS and PLCO datasets, only 2% of negative cases were misclassified as high risk and 6% of positive cases were misclassified as low risk. In modeling the CRC-free probability with Kaplan-Meier estimators, low-, medium-, and high CRC-risk groups have statistically-significant separation. Our results indicated that the trained artificial neural network can be used as an effective screening tool for early intervention and prevention of CRC in large populations.

A risk prediction tool for colorectal cancer screening: a qualitative study of patient and provider facilitators and barriers

BACKGROUND

Despite proven effectiveness of colorectal cancer (CRC) screening, at least 35% of screen-eligible adults are not current with screening. Decision aids and risk prediction tools may help increase uptake, adherence, and efficiency of CRC screening by presenting lower-risk patients with options less invasive than colonoscopy. The purpose of this qualitative study was to determine patient and provider perceptions of facilitators and barriers to use of a risk prediction tool for advanced colorectal neoplasia (CRC and advanced, precancerous polyps), to maximize its chances of successful clinical implementation.

METHODS

We conducted qualitative, semi-structured interviews with patients aged 50-75 years who were not current with CRC screening, and primary care providers (PCPs) at an academic and a U.S. Department of Veterans Affairs Medical Center in the Midwest from October 2016 through March 2017. Participants were asked about their current experiences discussing CRC screening, then were shown the risk tool and asked about its acceptability, barriers, facilitators, and whether they would use it to guide their choice of a screening test. The constant comparative method guided analysis.

RESULTS

Thirty patients and PCPs participated. Among facilitators were the tool's potential to increase screening uptake, reduce patient risk, improve resource allocation, and facilitate discussion about CRC screening. PCP-identified barriers included concerns about the tool's accuracy, consistency with guidelines, and time constraints.

CONCLUSIONS

Patients and PCPs found the risk prediction tool useful, with potential to increase uptake, safety, and efficiency of CRC screening, indicating potential acceptability and feasibility of implementation into clinical practice.

Colonoscopy Findings: A Single Institution Study from Pakistan

Introduction

Colonoscopy is a diagnostic procedure used not only for screening and assessment but also for therapeutic management of various diseases such as removal of polyps, flat lesions, etc. In this study, we determine various outcomes of colonoscopy done in the gastroenterology unit of Ghulam Muhammad Mahar Medical College and Teaching Hospital in Pakistan.

Methods and Materials

This retrospective cross-sectional review was carried out at the colonoscopy unit of Ghulam Muhammad Mahar Medical College and Teaching Hospital in Sukkur, Pakistan. Data was gathered from medical records of patients and by calling their physicians if necessary from July 1 to December 31, 2018. 

Results

In our study, the most common site for colonoscopy was a rectosigmoid colon (37.85%, n=134), almost parallel to the anal canal (37.57%, n=133). Normal colonoscopy was reported in 25.42% (n=90). The most common pathology was hemorrhoids (32.48%, n=115), followed by ulcers (17.79%, n=63).

Conclusion

Colonoscopic detection of hemorrhoids was the most common finding in colonoscopy. Normal colonoscopy was less compared to other literature, suggesting physicians are carefully screening patients in advising colonoscopies.

Scoring colorectal cancer risk with an artificial neural network based on self-reportable personal health data

Colorectal cancer (CRC) is third in prevalence and mortality among all cancers in the US. Currently, the United States Preventative Services Task Force (USPSTF) recommends anyone ages 50-75 and/or with a family history to be screened for CRC. To improve screening specificity and sensitivity, we have built an artificial neural network (ANN) trained on 12 to 14 categories of personal health data from the National Health Interview Survey (NHIS). Years 1997-2016 of the NHIS contain 583,770 respondents who had never received a diagnosis of any cancer and 1409 who had received a diagnosis of CRC within 4 years of taking the survey. The trained ANN has sensitivity of 0.57 ± 0.03, specificity of 0.89 ± 0.02, positive predictive value of 0.0075 ± 0.0003, negative predictive value of 0.999 ± 0.001, and concordance of 0.80 ± 0.05 per the guidelines of Transparent Reporting of Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD) level 2a, comparable to current risk-scoring methods. To demonstrate clinical applicability, both USPSTF guidelines and the trained ANN are used to stratify respondents to the 2017 NHIS into low-, medium- and high-risk categories (TRIPOD levels 4 and 2b, respectively). The number of CRC respondents misclassified as low risk is decreased from 35% by screening guidelines to 5% by ANN (in 60 cases). The number of non-CRC respondents misclassified as high risk is decreased from 53% by screening guidelines to 6% by ANN (in 25,457 cases). Our results demonstrate a robustly-tested method of stratifying CRC risk that is non-invasive, cost-effective, and easy to implement publicly.

Capability of four sigmoidoscopy-based screening strategies to predict proximal neoplasia in an asymptomatic Chinese population

BACKGROUND AND AIM

A proper colonoscopy referral criterion is essential for flexible sigmoidoscopy-based colorectal cancer screening. We aimed to compare the predictive capability of four existing criteria to detect proximal neoplasia (PN) and advanced proximal neoplasia (APN) in a Chinese population.

METHODS

Asymptomatic Chinese participants aged 50-75 years, who received screening colonoscopy, were consecutively recruited. The four criteria included (i) UK flexible sigmoidoscopy; (ii) Italian Screening for COlon REctum; (iii) NORwegian Colorectal Cancer Prevention trial; and (iv) US clinical index. The sensitivity, specificity, positive/negative predictive value, and the number of subjects needed to screen (NNS)/refer (NNR) to detect one APN/PN were examined. The area under receiver operating characteristic curve was evaluated.

RESULTS

Among 5833 subjects, 749 (12.8%) and 151 (2.6%) cases were found to have PN and APN, respectively. US criteria achieved the highest sensitivity for PN (49%) and APN (66%), while UK criteria attained the highest specificity (93%) for PN/APN. The lowest NNS was required by US criteria for PN (16 vs 19-38) and APN (58 vs 69-86), while the lowest NNR was required by UK criteria for PN (3.2 vs 4.0-4.8) and APN (7 vs 10-16). The receiver operating characteristic of all four criteria was 0.57-0.61 for PN and 0.68-0.70 for APN.

CONCLUSIONS

Among all the four criteria, US criteria had the highest sensitivity and lowest NNS, while UK criteria achieved the highest specificity and lowest NNR. Their limited discriminatory capability highlighted the need for a new score to predict PN/APN in Chinese populations.

Association between Cardiovascular Risk and Diabetes with Colorectal Neoplasia: A Site-Specific Analysis

Several studies have shown site-specific differences in colorectal cancer (CRC) with respect to the risk factors. CRC was shown to be associated with cardiovascular risk (CVR) factors, but site-specific variations have not been investigated so far. This study aimed to assess the associations between the prevalence and subsite-specific differences of colorectal neoplasia and established CVR scores or known coronary artery disease (CAD) in a large asymptomatic European screening cohort (N = 2098). Participants underwent simultaneous screening colonoscopy and CVR evaluation, using the Framingham Risk Score and Heart Score. Lesions found in the colonoscopy were classified by location (proximal/distal colon or rectum). More neoplasias were found in the proximal versus the distal colon (p < 0.001). The Framingham Risk Score and Heart Score showed incremental risk for colorectal adenoma, across the tertiles in the proximal and the distal colon (p < 0.001). The prevalence of adenomas in the rectum was much lower, but also here, incremental risk could be shown for the Framingham Risk but not the Heart Risk Score tertiles. Prevalence of adenomas in the proximal colon was higher in subjects with type 2 diabetes (T2DM) (p = 0.006), but no association was found between adenomas and T2DM in the distal colon (p = 0.618) and the rectum (p = 0.071). Males had a higher CVR and more findings, in the screening colonoscopy, as compared to females, however, no site-specific differences were noted. Patients with known CAD and high CVR have an increased risk of colorectal neoplasia in both the proximal and distal colon. Patients with T2DM have a higher risk for neoplasia in the proximal colon.

A scoring model for predicting advanced colorectal neoplasia in a screened population of asymptomatic Japanese individuals

BACKGROUND

Risk stratification of screened populations could help improve colorectal cancer (CRC) screening. Use of the modified Asia-Pacific Colorectal Screening (APCS) score has been proposed in the Asia-Pacific region. This study was performed to build a new useful scoring model for CRC screening.

METHODS

Data were reviewed from 5218 asymptomatic Japanese individuals who underwent their first screening colonoscopy. Multivariate logistic regression was used to investigate risk factors for advanced colorectal neoplasia (ACN), and a new scoring model for the prediction of ACN was developed based on the results. The discriminatory capability of the new model and the modified APCS score were assessed and compared. Internal validation was also performed.

RESULTS

ACN was detected in 225 participants. An 8-point scoring model for the prediction of ACN was developed using five independent risk factors for ACN (male sex, higher age, presence of two or more first-degree relatives with CRC, body mass index of > 22.5 kg/m², and smoking history of > 18.5 pack-years). The prevalence of ACN was 1.6% (34/2172), 5.3% (127/2419), and 10.2% (64/627) in participants with scores of < 3, ≥ 3 to < 5, and ≥ 5, respectively. The c-statistic of the scoring model was 0.70 (95% confidence interval, 0.67-0.73) in both the development and internal validation sets, and this value was higher than that of the modified APCS score [0.68 (95% confidence interval, 0.65-0.71), P = 0.03].

CONCLUSIONS

We built a new simple scoring model for prediction of ACN in a Japanese population that could stratify the screened population into low-, moderate-, and high-risk groups.

Screening-detected colorectal cancers show better long-term survival compared with stage-matched symptomatic cancers

PURPOSE

the aim of this study was to compare overall and disease-free survival among patients with colorectal cancer detected via a screening program as compared to those with symptomatic cancer.

MATERIAL AND METHODS

patients diagnosed via colonoscopy (screening group) and those with clinical symptoms (non-screening) were identified from 1995 to 2014. Demographic, clinical, surgical and pathologic variables were recorded. Stage I, II and III cancers were included. Overall and disease-free survival were calculated at five and ten years after tumor resection and survival was calculated by matching both groups for cancers at stage I, II and III.

RESULTS

two hundred and fifty patients were identified as a result of screening procedures and 1,330 patients presented with symptomatic cancers. There were no significant differences in the baseline characteristics between the two groups. Pathologic stage, degree of differentiation, perineural invasion and lymphovascular invasion were lower in the screening group (p < 0.01). Overall and disease-free survival at five and ten years were higher in the screening group (p < 0.01). However, when the subjects were matched for pathologic stage, significant differences were found between the two groups with regard to stage I and III tumors. Disease-free survival in stage III at five years (79.1 vs 61.7%; p < 0.001) and ten years (79.1% vs 58.5%; p < 0.001) were significantly higher in the screening group.

CONCLUSIONS

patients with stage I and III tumors that were diagnosed via a screening program have a higher overall and disease-free survival at five and ten years.

Development and validation of a prediction model for adenoma detection during screening and surveillance colonoscopy with comparison to actual adenoma detection rates

OBJECTIVE

The adenoma detection rate (ADR) varies widely between physicians, possibly due to patient population differences, hampering direct ADR comparison. We developed and validated a prediction model for adenoma detection in an effort to determine if physicians' ADRs should be adjusted for patient-related factors.

MATERIALS AND METHODS

Screening and surveillance colonoscopy data from the cross-sectional multicenter cluster-randomized Endoscopic Quality Improvement Program-3 (EQUIP-3) study (NCT02325635) was used. The dataset was split into two cohorts based on center. A prediction model for detection of ≥1 adenoma was developed using multivariable logistic regression and subsequently internally (bootstrap resampling) and geographically validated. We compared predicted to observed ADRs.

RESULTS

The derivation (5 centers, 35 physicians, overall-ADR: 36%) and validation (4 centers, 31 physicians, overall-ADR: 40%) cohort included respectively 9934 and 10034 patients (both cohorts: 48% male, median age 60 years). Independent predictors for detection of ≥1 adenoma were: age (optimism-corrected odds ratio (OR): 1.02; 95%-confidence interval (CI): 1.02-1.03), male sex (OR: 1.73; 95%-CI: 1.60-1.88), body mass index (OR: 1.02; 95%-CI: 1.01-1.03), American Society of Anesthesiology physical status class (OR class II vs. I: 1.29; 95%-CI: 1.17-1.43, OR class ≥III vs. I: 1.57; 95%-CI: 1.32-1.86), surveillance versus screening (OR: 1.39; 95%-CI: 1.27-1.53), and Hispanic or Latino ethnicity (OR: 1.13; 95%-CI: 1.00-1.27). The model's discriminative ability was modest (C-statistic in the derivation: 0.63 and validation cohort: 0.60). The observed ADR was considerably lower than predicted for 12/66 (18.2%) physicians and 2/9 (22.2%) centers, and considerably higher than predicted for 18/66 (27.3%) physicians and 4/9 (44.4%) centers.

CONCLUSION

The substantial variation in ADRs could only partially be explained by patient-related factors. These data suggest that ADR variation could likely also be due to other factors, e.g. physician or technical issues.

Common risk variants for colorectal cancer: an evaluation of associations with age at cancer onset

Common genetic risk variants for colorectal cancer (CRC) have been identified at approximately 40 loci by genome-wide association studies (GWAS). We investigated the association of these risk variants by age at onset of CRC using case-only and case-control analysis. A total of 1,962 CRC cases and 2,668 controls from two independent case-control studies conducted by Korea’s National Cancer Center were included in this study. We genotyped 33 GWAS-identified single-nucleotide polymorphisms (SNPs) associated with CRC risk. The risk allele in SNP rs704017, located at 10q22.3 in the ZMIZ1-AS1 gene, was consistently less frequent among CRC patients aged <50 years than among CRC patients aged ≥50 years in the case-only analysis (odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.66–0.92, P = 2.7 × 10⁻³, in an additive model), although this did not surpass the threshold for multiple testing. The direction of associations between rs704017 and CRC risk differed by age group in the combined case-control analysis (<50 years: OR = 0.77, 95% CI = 0.60–0.98, P = 0.03 and ≥50 years: OR = 1.13, 95% CI = 0.98–1.29, P = 0.09, in a dominant model); the p-values for heterogeneity (P_{heterogeneity} = 7.5 × 10⁻³) and for interaction were statistically significant (P_interaction = 7.8 × 10⁻³, in the dominant model). Our results suggest that the CRC susceptibility SNP rs704017 has a hereditary effect on onset age of CRC.

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

Background

There is no validated, discriminating, and easy-to-apply tool for estimating risk of colorectal neoplasia. We studied whether the National Cancer Institute's (NCI's) Colorectal Cancer (CRC) Risk Assessment Tool, which estimates future CRC risk, could estimate current risk for advanced colorectal neoplasia among average-risk persons.

Methods

This cross-sectional study involved individuals age 50 to 80 years undergoing first-time screening colonoscopy. We measured medical and family history, lifestyle information, and physical measures and calculated each person's future CRC risk using the NCI tool's logistic regression equation. We related quintiles of future CRC risk to the current risk of advanced neoplasia (sessile serrated polyp or tubular adenoma ≥ 1 cm, a polyp with villous histology or high-grade dysplasia, or CRC). All statistical tests were two-sided.

Results

For 4457 (98.5%) with complete data (mean age = 57.2 years, SD = 6.6 years, 51.7% women), advanced neoplasia prevalence was 8.26%. Based on quintiles of five-year estimated absolute CRC risk, current risks of advanced neoplasia were 2.1% (95% confidence interval [CI] = 1.3% to 3.3%), 4.8% (95% CI = 3.5% to 6.4%), 6.4% (95% CI = 4.9% to 8.2%), 10.0% (95% CI = 8.1% to 12.1%), and 17.6% (95% CI = 15.5% to 20.6%; P < .001). For quintiles of estimated 10-year CRC risk, corresponding current risks for advanced neoplasia were 2.2% (95% CI = 1.4% to 3.5%), 4.8% (95% CI = 3.5% to 6.4%), 6.5% (95% CI = 5.0% to 8.3%), 9.3% (95% CI = 7.5% to 11.4%), and 18.4% (95% CI = 15.9% to 21.1%; P < .001). Among persons with an estimated five-year CRC risk above the median, current risk for advanced neoplasia was 12.8%, compared with 3.7% among those below the median (relative risk = 3.4, 95 CI = 2.7 to 4.4).

Conclusions

The NCI's Risk Assessment Tool, which estimates future CRC risk, may be used to estimate current risk for advanced neoplasia, making it potentially useful for tailoring and improving CRC screening efficiency among average-risk persons.

Comparison of biomarker expression between proximal and distal colorectal adenomas: The Tennessee-Indiana Adenoma Recurrence Study

It is unclear if proximal and distal traditional adenomas present with differences in molecular events which contribute to cancer heterogeneity by tumor anatomical subsite. Participants from a colonoscopy-based study (n = 380) were divided into subgroups based on the location of their most advanced adenoma: proximal, distal, or "equivalent both sides." Eight biomarkers in the most advanced adenomas were evaluated by immunohistochemistry (Ki-67, COX-2, TGFβRII, EGFR, β-catenin, cyclin D1, c-Myc) or TUNEL (apoptosis). After an adjustment for pathological features, there were no significant differences between proximal and distal adenomas for any biomarker. Conversely, expression levels did vary by other features, such as their size, villous component, and synchronousness. Large adenomas had higher expression levels of Ki-67(P < 0.001), TGFβRII (P < 0.0001), c-Myc (P < 0.001), and cyclin D1 (P < 0.001) in comparison to small adenomas, and tubulovillous/villous adenomas also were more likely to have similar higher expression levels in comparison to tubular adenomas. Adenoma location is not a major determinant of the expression of these biomarkers outside of other pathological features. This study suggests similarly important roles of Wnt/β-catenin and TGF-β pathways in carcinogenesis in both the proximal and distal colorectum. © 2016 Wiley Periodicals, Inc.

The discriminatory capability of existing scores to predict advanced colorectal neoplasia: a prospective colonoscopy study of 5,899 screening participants

We evaluated the performance of seven existing risk scoring systems in predicting advanced colorectal neoplasia in an asymptomatic Chinese cohort. We prospectively recruited 5,899 Chinese subjects aged 50–70 years in a colonoscopy screening programme(2008–2014). Scoring systems under evaluation included two scoring tools from the US; one each from Spain, Germany, and Poland; the Korean Colorectal Screening(KCS) scores; and the modified Asia Pacific Colorectal Screening(APCS) scores. The c-statistics, sensitivity, specificity, positive predictive values(PPVs), and negative predictive values(NPVs) of these systems were evaluated. The resources required were estimated based on the Number Needed to Screen(NNS) and the Number Needed to Refer for colonoscopy(NNR). Advanced neoplasia was detected in 364 (6.2%) subjects. The German system referred the least proportion of subjects (11.2%) for colonoscopy, whilst the KCS scoring system referred the highest (27.4%). The c-statistics of all systems ranged from 0.56–0.65, with sensitivities ranging from 0.04–0.44 and specificities from 0.74–0.99. The modified APCS scoring system had the highest c-statistics (0.65, 95% C.I. 0.58–0.72). The NNS (12–19) and NNR (5-10) were similar among the scoring systems. The existing scoring systems have variable capability to predict advanced neoplasia among asymptomatic Chinese subjects, and further external validation should be performed.

Evaluation of a clinical risk index for advanced colorectal neoplasia among a North American population of screening age

Background

A clinical risk index employing age, sex, family history of colorectal cancer (CRC), smoking history and body mass index (BMI) may be useful for prioritizing screening with colonoscopy. The aim of this study was to conduct an external evaluation of a previously published risk index for advanced neoplasia (AN) in a large, well-characterized cohort.

Methods

Five thousand one hundred thirty-seven asymptomatic persons aged 50 to 74 (54.9 % women) with a mean age (SD) of 58.3 (6.2) years were recruited for the study from a teaching hospital and colorectal cancer screening centre between 2003 and 2011. All participants underwent a complete screening colonoscopy and removal of all polyps. AN was defined as cancer or a tubular adenoma, traditional serrated adenoma (TSA), or sessile serrated adenoma (SSA) with villous characteristics (≥25% villous component), and/or high-grade dysplasia and/or diameter ≥10 mm. Risk scores for each participant were summed to derive an overall score (0–8). The c-statistic was used to measure discriminating ability of the risk index.

Results

The prevalence of AN in the study cohort was 6.8 %. The likelihood of detecting AN increased from 3.6 to 13.1 % for those with a risk score of 1 to 6 respectively. The c-statistic for the multivariable logistic model in our cohort was 0.64 (95 % CI = 0.61–067) indicating modest overlap between risk scores.

Conclusions

The risk index for AN using age, sex, family history, smoking history and BMI was found to be of limited discriminating ability upon external validation. The index requires further refinement to better predict AN in average risk persons of screening age.

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.

Overweight increases the risk of malignancy in patients with pancreatic mucinous cystic neoplasms

Distinguishing between benign and malignant pancreatic cysts remains a clinical challenge. The aim of this study was to investigate the influence of body mass index (BMI) and preoperative clinical and cyst features, as described by the International Consensus Guidelines, on malignancy in patients with pancreatic mucinous cystic neoplasms (PMCNs).A retrospective cohort study was performed on patients with PMCNs who underwent surgical resection between January 1994 and June 2014. Preoperative BMI, clinical demographic data, cystic features, tumor markers, and surgical pathology results were analyzed. Predictors of malignancy were determined by univariate and multivariate analysis using logistic regression.One hundred sixty-four cases of PMCNs, including 106 intraductal papillary mucinous neoplasms (IPMNs) and 58 mucinous cystic neoplasms (MCNs), were analyzed. On univariate analysis, older age (P = 0.008), male sex (P = 0.007), high-risk stigmata (P = 0.007), diabetes mellitus (DM; P = 0.008), and BMI >25 (P < 0.001) were associated with malignancy. Multivariate analysis found that BMI >25 (odds ratio, 3.99; 95% confidence interval: 1.60-10) was an independent predictor of malignancy. In subgroup analysis, BMI >25 was an independent predictor of malignancy in IPMNs but not in MCNs.Overweight patients with IPMNs have a higher risk of malignancy and should be followed closely or undergo resection. The operative strategy for PMCNs should consider cyst-related and patient-related risk factors.

Assessing individual risk for high-risk colorectal adenoma at first-time screening colonoscopy

Assessing risk of colorectal adenoma at first-time colonoscopy that are of higher likelihood of developing advanced neoplasia during surveillance could help tailor first-line colorectal cancer screening. We developed prediction models for high-risk colorectal adenoma (at least one adenoma ≥1 cm, or with advanced histology, or ≥3 adenomas) among 4,881 asymptomatic white men and 17,970 women who underwent colonoscopy as their first-time screening for colorectal cancer in two prospective US studies using logistic regressions. C-statistics and Hosmer-Lemeshow tests were used to evaluate discrimination and calibration. Ten-fold cross-validation was used for internal validation. A total of 330 (6.7%) men and 678 (3.8%) women were diagnosed with high-risk adenoma at first-time screening colonoscopy. The model for men included age, family history of colorectal cancer, BMI, smoking, sitting watching TV/VCR, regular aspirin/NSAID use, physical activity, and a joint term of multivitamin and alcohol. For women, the model included age, family history of colorectal cancer, BMI, smoking, alcohol, beef/pork/lamb as main dish, regular aspirin/NSAID, calcium, and oral contraceptive use. The C-statistic of the model for men was 0.67 and 0.60 for women (0.64 and 0.57 in cross-validation). Both models calibrated well. The predicted risk of high-risk adenoma for men in the top decile was 15.4% vs. 1.8% for men in the bottom decile (Odds Ratio [OR] = 9.41), and 6.6% vs. 2.1% for women (OR = 3.48). In summary, we developed and internally validated an absolute risk assessment tool for high-risk colorectal adenoma among the US population that may provide guidance for first-time colorectal cancer screening.

Is surveillance colonoscopy necessary for patients with sporadic gastric hyperplastic polyps?

Background

Gastric polyps, such as adenomas and hyperplastic polyps, can be found in various colonic polyposis syndromes. Unlike in sporadic gastric adenomas, in which the increased risk of colorectal neoplasia has been well characterized, information in sporadic gastric hyperplastic polyps was limited.

Aim

To evaluate the association of sporadic gastric hyperplastic polyps with synchronous colorectal neoplasia in a large cohort.

Methods

Patients with sporadic gastric hyperplastic polyps who underwent colonoscopy simultaneously or within six months were consecutively enrolled. Each patient was compared with two randomly selected age and sex matched controls without gastric polyps who also underwent colonoscopy in the same period. Data of patients’ demographics and characteristics of the gastrointestinal polyps were documented.

Results

A total of 261 cases in 118,576 patients who underwent esophagogastroduodenoscopy were diagnosed as sporadic gastric hyperplastic polyps, and 192 of 261 (73.6%) patients underwent colonoscopy. Colorectal neoplasias were identified in 46 (24.0%) of 192 cases and in 40 (10.4%) of 384 controls (P＜0.001). The mean size and distribution of colorectal neoplasias were not significantly different between the two groups. There was a significantly higher rate of colorectal adenoma (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.9–5.3) in the gastric hyperplastic polyps group than in the control group, while the prevalence of colorectal cancer was similar in the two groups. Logistic regression analysis also suggested that the presence of gastric hyperplastic polyps (OR 2.5, 95% CI 1.5–4.0) was an independent risk factor for colorectal neoplasias.

Conclusion

The risk of colorectal adenoma increases in patients with sporadic gastric hyperplastic polyps, and surveillance colonoscopy for these patients should be considered.

History, evolution, and current status of radiologic imaging tests for colorectal cancer screening

Colorectal cancer screening is thought to be an effective tool with which to reduce the mortality from colorectal cancer through early detection and removal of colonic adenomas and early colon cancers. In this article, we review the history, evolution, and current status of imaging tests of the colon-including single-contrast barium enema, double-contrast barium enema, computed tomographic (CT) colonography, and magnetic resonance (MR) colonography-for colorectal cancer screening. Despite its documented value in the detection of colonic polyps, the double-contrast barium enema has largely disappeared as a screening test because it is widely perceived as a labor-intensive, time-consuming, and technically demanding procedure. In the past decade, the barium enema has been supplanted by CT colonography as the major imaging test in colorectal cancer screening in the United States, with MR colonography emerging as another viable option in Europe. Although MR colonography does not require ionizing radiation, the radiation dose for CT colonography has decreased substantially, and regular screening with this technique has a high benefit-to-risk ratio. In recent years, CT colonography has been validated as an effective tool for use in colorectal cancer screening that is increasingly being disseminated.

Should prior FIT results be incorporated as an additional variable to estimate risk of colorectal neoplasia? A prospective study of 5,813 screening colonoscopies

Background

Recent studies showed that previous negative results from faecal immunochemical tests (FITs) for colorectal cancer (CRC) screening was associated with lower risk of advanced neoplasia (AN). We evaluated whether prior FIT results should be included to estimate the risk of AN in 2008–2012.

Methods

A community-based screening practice recruited 5,813 asymptomatic residents aged 50 to 70 years in Hong Kong for CRC screening. We included study participants who had (1). positive FIT with subsequent colonoscopy workup (FIT+ group; n = 356); (2). negative FIT in three consecutive years and received a colonoscopy (FIT- group; n = 857); (3). received colonoscopy without FIT (colonoscopy group; n = 473); and (4). received both colonoscopy and FIT at the same time (combined group; n = 4,127). One binary logistic regression model evaluated whether prior FIT results were associated with colonoscopy findings of AN.

Results

The proportion of participants having AN/CRC was 18.0% (FIT+), 5.5% (FIT-), 8.0% (colonoscopy group), and 4.3% (combined group), respectively. When compared with the colonoscopy group, those in the FIT- group were not significantly more or less likely to have AN/CRC (AOR  = 0.77, 95% C.I. = 0.51 to 1.18, p  = 0.230). Having one (AOR = 0.73, 95% C.I. 0.48–1.12, p = 0.151) or three consecutive negative FIT result (AOR = 0.98, 95% C.I. 0.60–1.62, p = 0.944) were not associated with lower risks of AN/CRC. Subjects in the FIT+ group was 3.32-fold (95% C.I. 2.07 to 5.32, p<0.001) more likely to have AN/CRC.

Conclusions

These findings indicated that subjects with negative FIT findings could be risk stratified similarly as those who had not previously received FIT.

Routine colonic endoscopic evaluation following resolution of acute diverticulitis: Is it necessary?

Diverticular disease incidence is increasing up to 65% by age 85 in industrialized nations, low fiber diets, and in younger and obese patients. Twenty-five percent of patients with diverticulosis will develop acute diverticulitis. This imposes a significant burden on healthcare systems, resulting in greater than 300000 admissions per year with an estimated annual cost of $3 billion USD. Abdominal computed tomography (CT) is the diagnostic study of choice, with a sensitivity and specificity greater than 95%. Unfortunately, similar CT findings can be present in colonic neoplasia, especially when perforated or inflamed. This prompted professional societies such as the American Society of Colon Rectal Surgeons to recommend patients undergo routine colonoscopy after an episode of acute diverticulitis to rule out malignancy. Yet, the data supporting routine colonoscopy after acute diverticulitis is sparse and based small cohort studies utilizing outdated technology. While any patient with an indication for a colonoscopy should undergo appropriate endoscopic evaluation, in the era of widespread use of high-resolution computed tomography, routine colonic endoscopic evaluation following resolution of acute uncomplicated diverticulitis poses additional costs, comes with inherent risks, and may require further study. In this manuscript, we review the current data related to this recommendation.

Prediction rule for estimating advanced colorectal neoplasm risk in average-risk populations in southern Jiangsu Province

OBJECTIVE

The aim of this study was to establish the risk scoring system towards the advanced colorectal neoplasm (CN) risk in the average-risk populations in the southern Jiangsu Province, and to evaluate the screening efficacy.

METHODS

Totally 905 cases of the average-risk populations who received the colonoscopy were selected as the objective. The multivariate logistic regression analysis method was used to establish the scoring system towards the occurrence risk of the advanced tumor, and its screening efficacy was evaluated through the prediction consistency, distinguishing ability and screening accuracy.

RESULTS

The scoring system consisted of five variables, namely age, gender, coronary heart disease, egg intake and stool frequency. The results revealed that it had good prediction consistency (P=0.205) and distinguishing ability [the area under the receiver operating characteristic (ROC) curve was 0.75, with 95% confidence interval (95% CI) of 0.69-0.82]. Thus, 2.5 points was set as the screening cutoff value, and its sensitivity, specificity, accuracy, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were 93.8%, 47.6%, 50.1%, 9.1%, 99.3%, 1.79 and 0.13, respectively.

CONCLUSIONS

The established scoring system had good screening efficacy, and can be used as the screening tool applying to the CN screening within the average-risk populations in the southern Jiangsu Province.

Routine colonoscopy is not required in uncomplicated diverticulitis: a systematic review

BACKGROUND

It is generally accepted that patients following an episode of diverticulitis should have additional colonoscopy screening to rule out a colorectal malignancy. We aimed to investigate the rate of CRC found by colonoscopy after an attack of uncomplicated diverticulitis.

METHODS

MEDLINE, Embase, and Cochrane databases were searched systematically for clinical trials or observational studies on colonic evaluation by colonoscopy after the initial diagnosis of acute uncomplicated diverticulitis, followed by hand-searching of reference lists.

RESULTS

Nine studies met the inclusion criteria and included a total number of 2,490 patients with uncomplicated diverticulitis. Subsequent colonoscopy after an episode of uncomplicated diverticulitis was performed in 1,468 patients (59%). Seventeen patients were diagnosed with CRC, having a prevalence of 1.16% (95% confidence interval 0.72-1.9% for CRC). Hyperplastic polyps were seen in 156 patients (10.6%), low-grade adenoma in 90 patients (6.1%), and advanced adenoma was reported in 32 patients (2.2%).

CONCLUSION

Unless colonoscopy is regarded for screening in individuals aged 50 years and older, routine colonoscopy in the absence of other clinical signs of CRC is not required.

Derivation and validation of a prediction rule for estimating colorectal neoplasm risk in asymptomatic individuals in southern Jiangsu province

AIM: To develop a prediction rule to stratify risk for colorectal neoplasms in asymptomatic individuals in southern Jiangsu province, and to evaluate its screening efficiency.

METHODS: Asymptomatic persons in southern Jiangsu province who had complete colonoscopy data were included in this study. All participants were asked to complete a questionnaire which covered information on potential risk factors, including demographic characteristics, medical history, smoking, alcohol consumption, dietary intake, and other factors that may be associated with colorectal neoplasms. A multivariable logistic regression method was used to identify independent predictors of colorectal neoplasms. A prediction rule was developed from the logistic regression model by using a regression coefficient-based scoring method, and then internally validated. The screening efficiency of the prediction rule was assessed by its calibration, discrimination, and accuracy.

RESULTS: A total of 905 asymptomatic persons were included in this study. The prediction rule comprised three variables (age, smoking, and alcohol consumption), with scores ranging from 0 to 6. The prediction rule had good calibration (P = 0.093) and good discrimination (area under the receiver operating characteristic curve = 0.65, 95%CI: 0.61-0.69). When a score of 1.5 was used as the screening cutoff value, the sensitivity, specificity, accuracy, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 65.1%, 57.2%, 59.9%, 44.4%, 75.7%, 1.52, and 0.61, respectively.

CONCLUSION: The developed prediction rule had good screening efficiency and, thus, can be used as a preliminary method to screen colorectal neoplasms in asymptomatic individuals in southern Jiangsu province.

Prevalence of and risk factors for gastrointestinal diseases in korean americans and native koreans undergoing screening endoscopy

BACKGROUND/AIMS

In South Korea, health check-ups are readily accessible to the public. We aimed to compare the prevalence of upper gastrointestinal (GI) and lower GI diseases in Korean Americans and native Koreans to determine differences and risk factors.

METHODS

In total, 1,942 subjects who visited Gangnam Severance Hospital from July 2008 to November 2010 for a health check-up were enrolled. Basic characteristics and laboratory data for the subjects were collected. Esophagogastroduodenoscopy and colonoscopy were performed. In total, 940 Korean Americans (group 1) and 1,002 native Koreans (group 2) were enrolled.

RESULTS

The overall prevalence of GI diseases for each group (group 1 vs group 2) were as follows: reflux esophagitis (RE) (9.65% vs 7.9%), gastric ulcer (2.8% vs 3.4%), duodenal ulcer (2.3% vs 3.6%), gastric cancer (0.4% vs 0.3%), colorectal polyp (35.9% vs 35.6%), colorectal cancer (0.5% vs 0.5%), and hemorrhoids (29.4% vs 21.3%). The prevalence of hemorrhoids was significantly higher in group 1 than in group 2 (p=0.001). In the multivariable analysis of group 1, male sex, age over 50 years, hypercholesterolemia and hypertriglyceridemia predicted colorectal polyps. Male sex and high fasting glucose levels were associated with RE.

CONCLUSIONS

Our study showed that the prevalence of GI diseases (except hemorrhoids) in Korean Americans was similar to that observed in native Koreans. Therefore, the Korean guidelines for upper and lower screening endoscopy may be applicable to Korean Americans.

The Your Disease Risk Index for colorectal cancer is an inaccurate risk stratification tool for advanced colorectal neoplasia at screening colonoscopy

Tailoring the use of screening colonoscopy based on the risk of advanced colorectal neoplasia (ACN) could optimize the cost-effectiveness of colorectal cancer (CRC) screening. Our goal was to assess the accuracy of the Your Disease Risk (YDR) CRC risk index for stratifying average risk patients into low- versus intermediate/high-risk categories for ACN. The YDR risk assessment tool was administered to 3,317 asymptomatic average risk patients 50 to 79 years of age just before their screening colonoscopy. Associations between YDR-derived relative risk (RR) scores and ACN prevalence were examined using logistic regression and χ(2) analyses. ACN was defined as a tubular adenoma ≥1 cm, tubulovillous or villous adenoma of any size, and the presence of high-grade dysplasia or cancer. The overall prevalence of ACN was 5.6%. Although YDR-derived RR scores were linearly associated with ACN after adjusting for age and gender (P = 0.033), the index was unable to discriminate "below average" from "above/average" risk patients [OR, 1.01; 95% confidence interval (CI), 0.75-1.37]. Considerable overlap in rates of ACN was also observed between the different YDR risk categories in our age- and gender-stratified analyses. The YDR index lacks accuracy for stratifying average risk patients into low- versus intermediate/high-risk categories for ACN.

Colon capsule endoscopy: Advantages, limitations and expectations. Which novelties?

Since the first reports almost ten years ago, wireless capsule endoscopy has gained new fields of application. Colon capsule endoscopy represents a new diagnostic technology for colonic exploration. Clinical trials have shown that colon capsule endoscopy is feasible, accurate and safe in patients suffering from colonic diseases and might be a valid alternative to conventional colonoscopy in selected cases such as patients refusing conventional colonoscopy or with contraindications to colonoscopy or when colonoscopy is incomplete. Despite the enthusiasm surrounding this new technique, few clinical and randomized controlled trials are to be found in the current literature, leading to heterogeneous or controversial results. Upcoming studies are needed to prove the substantial utility of colon capsule endoscopy for colon cancer screening, especially in a low prevalence of disease population, and for other indications such as inflammatory bowel disease. Possible perspectives are critically analysed and reported in this paper.

Korean guidelines for colorectal cancer screening and polyp detection

Now colorectal cancer is the second most common cancer in males and the fourth most common cancer in females in Korea. Since most of colorectal cancers occur after the prolonged transformation of adenomas into carcinomas, early detection and removal of colorectal adenomas are one of the most effective methods to prevent colorectal cancer. Considering the increasing incidence of colorectal cancer and polyps in Korea, it is very important to establish Korean guideline for colorectal cancer screening and polyp detection. The guideline was developed by the Korean Multi-Society Take Force and we tried to establish the guideline by evidence-based methods. Parts of the statements were draw by systematic reviews and meta-analyses. Herein we discussed epidemiology of colorectal cancers and adenomas in Korea and optimal methods for screening of colorectal cancer and detection of adenomas including fecal occult blood tests, radiologic tests, and endoscopic examinations.

Increased prevalence of colorectal neoplasia in korean patients with sporadic duodenal adenomas: a case-control study

Background/Aims

Recent data from Western populations have suggested that patients with sporadic duodenal adenomas are at a higher risk for the development of colorectal neoplasia. In this study, we compared the frequency of colorectal neoplasia in patients with sporadic duodenal adenomas to healthy control subjects.

Methods

This retrospective case-control study used the databases of 3 teaching hospitals in Gyeonggi-do Province, South Korea. The colonoscopy findings of patients with sporadic duodenal adenomas were compared with those of age- and gender-matched healthy individuals who had undergone gastroduodenoscopies and colonoscopies during general screening examinations.

Results

Between 2001 and 2008, 45 patients were diagnosed endoscopically with sporadic duodenal adenomas; 26 (58%) of these patients received colonoscopies. Colorectal neoplasia (42% vs 21%; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.1 to 7.4) and advanced colorectal adenoma (19% vs 3%; OR, 9.0; 95% CI, 1.6 to 50.0) were significantly more common in patients with sporadic duodenal adenomas than in healthy control subjects.

Conclusions

Compared with healthy individuals, patients with sporadic duodenal adenomas were at a significantly higher risk for developing colorectal neoplasia. Such at-risk patients should undergo routine screening colonoscopies.

Cutoff value determines the performance of a semi-quantitative immunochemical faecal occult blood test in a colorectal cancer screening programme

Background:

The cutoff of semi-quantitative immunochemical faecal occult blood tests (iFOBTs) influences colonoscopy referrals and detection rates. We studied the performance of an iFOBT (OC-Sensor) in colorectal cancer (CRC) screening at different cutoffs.

Methods:

Dutch screening participants, 50–75 years of age, with average CRC risk and an iFOBT value ⩾50 ng ml⁻¹ were offered colonoscopy. The detection rate was the percentage of participants with CRC or advanced adenomas (⩾10 mm, ⩾20% villous, high-grade dysplasia). The number needed to scope (NNTScope) was the number of colonoscopies to be carried out to find one person with CRC or advanced adenomas.

Results:

iFOBT values ⩾50 ng ml⁻¹ were detected in 526 of 6157 participants (8.5%) and 428 (81%) underwent colonoscopy. The detection rate for advanced lesions (28 CRC and 161 with advanced adenomas) was 3.1% (95% confidence interval: 2.6–3.5%) and the NNTScope was 2.3. At 75 ng ml⁻¹, the detection rate was 2.7%, the NNTScope was 2.0 and the CRC miss rate compared with 50 ng ml⁻¹ was <5% (N=1). At 100 ng ml⁻¹, the detection rate was 2.4% and the NNTScope was <2. Compared with 50 ng ml⁻¹, up to 200 ng ml⁻¹ CRC miss rates remained at 16% (N=4).

Conclusions:

Cutoffs below the standard 100 ng ml⁻¹ resulted in not only higher detection rates of advanced lesions but also more colonoscopies. With sufficient capacity, 75 ng ml⁻¹ might be advised; if not, up to 200 ng ml⁻¹ CRC miss rates are acceptable compared with the decrease in performed colonoscopies.

Colorectal Neoplasm in Asymptomatic Average-risk Koreans: The KASID Prospective Multicenter Colonoscopy Survey

BACKGROUND/AIMS

The incidence of colorectal cancer is increasing in Korea, but the epidemiology of colorectal neoplasm is not clearly defined. We aimed to elucidate the prevalence of colorectal neoplasm in average-risk Koreans and explore the underlying risk factors.

METHODS

A large-scale, multicenter, prospective study was conducted. Of the 19,460 subjects who underwent colonoscopy at 11 university hospitals, we analyzed 3,951 consecutive asymptomatic adults with no risk factors for colorectal cancer.

RESULTS

The subjects were aged 52.1+/-11.6 years (mean+/-SD) and 60.1% of them were men. The prevalences of colorectal neoplasm and advanced neoplasm were 33.3% and 2.2%, respectively. The prevalence of a neoplasm increased with age (trend: p<0.001) and was higher in males (p<0.001). The prevalence of a proximal neoplasm was higher in subjects with a distal neoplasm than in those without a distal neoplasm (11.9% vs. 5.4%, p<0.001). However, 150 (52.1%) of the 288 subjects with a proximal neoplasm had no distal neoplasm.

CONCLUSIONS

The overall prevalence of colorectal neoplasm in asymptomatic average-risk Koreans is comparable with that in Western countries. Being male and older are associated with a higher risk of colorectal neoplasm. Over half of proximal neoplasms are not associated with any distal sentinel lesions.

Factors that increase risk of colon polyps

Adenomatous polyps are common and factors that increase risk include race, gender, smoking, and obesity. This author summarizes the evidence supporting increased risk with these factors and describes how epidemiological data may be used to tailor screening programs.

Screening CT colonography in an asymptomatic average-risk Asian population: a 2-year experience in a single institution

OBJECTIVE

The purpose of our study was to report the results of screening CT colonography (CTC) in an asymptomatic average-risk Asian population.

MATERIALS AND METHODS

In 2005 and 2006, 1,015 Korean adults (609 men and 406 women; mean age, 51 years) underwent screening CTC using a 16-MDCT scanner and an automated CO2 delivery system. During the study period, the protocols were changed to use less vigorous purgation and lower radiation doses; fecal tagging (n = 890) and primary 3D interpretation (n = 966) were generally used. CTC results were categorized as C0, inadequate; C1, no significant polyp; C2, one or two 6- to 9-mm polyps; C3, polyps > or = 10 mm or > or = three 6- to 9-mm polyps; and C4, mass. Patients with positive CTC results were referred to gastroenterologists for follow-up or management planning.

RESULTS

Categories C0-C4 were assigned to 21 (2.1%), 916 (90.2%), 54 (5.3%), 23 (2.3%), and one (0.1%) patients, respectively. Fifty-four patients with C4 (n = 1), C3 (n = 20), or C2 (n = 33) underwent subsequent optical colonoscopy: complete (n = 53) and incomplete (n = 1). Per-patient positive predictive values (PPVs) for categories C3-C4 and C2-C4 were 90% (18/20) and 74% (39/53), respectively. Per-polyp PPVs at 10- and 6-mm thresholds were 92% (22/24) and 69% (45/65), respectively. The diagnostic yield for advanced neoplasm was 1.5% (15/1,015).

CONCLUSION

Our results seem comparable to Western experiences, showing that a successful screening CTC program can be reproduced in an Asian population.

Colon capsule endoscopy

Wireless capsule endoscopy has become the first imaging tool for small bowel examination. Recently, new capsule endoscopy applications have been developed, such as esophageal capsule endoscopy and colon capsule endoscopy. Clinical trials results have shown that colon capsule endoscopy is feasible, accurate and safe in patients suffering from colonic diseases. It could be a good alternative in patients refusing conventional colonoscopy or when it is contraindicated. Upcoming studies are needed to demonstrate its utility for colon cancer screening and other indications such us ulcerative colitis. Comparative studies including both conventional and virtual colonoscopy are also required.

Screening colonoscopy in asymptomatic average-risk Koreans: analysis in relation to age and sex

BACKGROUND AND AIMS

Although the incidence of colorectal cancer is rising in Asian countries, there are no guidelines for its screening in this region due in part to the lack of epidemiological data regarding colorectal neoplasms. This study aimed to evaluate the prevalence of colorectal neoplasms in average-risk Koreans and to assess the effectiveness of screening colonoscopy in Korea.

METHODS

The prevalence of colorectal neoplasms was assessed by primary screening colonoscopy in 5,086 consecutive asymptomatic adults (males 70.5%; age 20-84 years) with no risk factors for colorectal cancer.

RESULTS

The overall prevalence of colorectal neoplasms in the 5,086 subjects was 21.9% and this increased linearly with age. Among the 2,435 subjects aged >or=50 years (males 66.7%; mean age 57.7 years), the prevalence of all colorectal neoplasms was 30.2% (males 35.9% vs females 18.7%; P < 0.001), while advanced neoplasms accounted for only 4.1% (males 5.1% vs females 2.0%; P < 0.001). The prevalence of advanced neoplasms in Korean men of a specific age group was similar to that of Korean women in the 10-years older age group. Also, Koreans in a specific age group showed a prevalence of advanced neoplasms similar to that of Westerners in the 10-years younger age group.

CONCLUSIONS

Colonoscopy is a useful modality for colorectal cancer screening in Korea, as established in Western countries. However, the screening colonoscopy may begin at an older age for Koreans than for Westerners. Similarly, the optimal starting age for screening in Korean women may be higher than that in men by 10 years.

Colorectal Cancer: Screening Double-Contrast Barium Enema Examination in Average-Risk Adults Older Than 50 Years

PURPOSE

To retrospectively determine the diagnostic yield of double-contrast barium enema examinations performed for colorectal cancer screening of neoplasms 1 cm or larger or advanced neoplastic lesions of any size in average-risk adults older than 50 years.

MATERIALS AND METHODS

The Institutional Review Board at the affiliated Veterans Affairs Medical Center approved this HIPAA-compliant study protocol and did not require informed consent from patients. Computerized databases revealed 276 double-contrast barium enema examinations performed for colorectal cancer screening in average-risk adults older than 50 years. Radiographic and pathologic reports were reviewed to determine the number of patients who had polypoid lesions 1 cm or larger, polyps smaller than 1 cm, or advanced neoplastic lesions of any size. Forty-five (16.3%) of the 276 patients underwent follow-up sigmoidoscopy or colonoscopy. Medical, endoscopic, and pathologic records were reviewed and compared with radiographic findings.

RESULTS

The results of double-contrast barium enema examination revealed 74 (26.8%) of 276 patients with 104 polypoid lesions in the colon, including 32 patients (11.6%) with 41 polypoid lesions 1 cm or larger, 15 patients (5.4%) with 19 polyps 6-9 mm, and 27 patients (9.8%) with 44 polyps 5 mm or smaller. Endoscopy was performed in 24 (75%) of 32 patients, the results of which confirmed 23 (72%) of 32 radiographically diagnosed lesions 1 cm or larger in 16 (67%) of 24 patients. In two of these individuals, the polyps were hyperplastic. The remaining 14 patients had a total of 21 neoplastic lesions 1 cm or larger, including 11 tubular adenomas, seven tubulovillous adenomas, one villous adenoma with marked dysplasia, and two cancers. The diagnostic yield of screening double-contrast barium enema examination was 5.1% (14 of 276 patients) for neoplastic lesions 1 cm or larger and 6.2% (17 of 276 patients) for advanced neoplastic lesions of any size.

CONCLUSION

Double-contrast barium enema examinations performed in average-risk adults older than 50 years have a diagnostic yield of 5.1% for neoplastic lesions 1 cm or larger and 6.2% for advanced neoplastic lesions, regardless of size.

The rare epidemiologic coincidence of diverticular disease and advanced colonic neoplasia

BACKGROUND AND AIMS

In Western industrialised countries the prevalence of neoplastic colonic lesions and diverticular disease markedly increases with age. In contrast, the coincident occurrence of both diseases seems to fall below their individual epidemiologic estimates. Because directly comparing data are rare, this retrospective study evaluates the coincidence of neoplastic lesions and diverticular disease.

PATIENT AND METHODS

A total of 1,838 patients from 1986 to 2000 were admitted to the study. For 1,326 patients-56% male (n=741), 44% female (n=585), mean age 64 (+/-11.83 SD)-with a resection due to colonic cancer, the documented findings of colonoscopy, colonic contrast enema, and/or histopathology were analysed with regard to the prevalence of colonic diverticulosis. In 512 patients--51% male (n=263), 49% female (n=249), mean age 60 (+/-12.59 SD)--with a colonic resection due to diverticulitis, the synchronous or metachronous occurrence of neoplastic colonic lesions was recorded using the database of the Tumour Centre, Aachen. To compare the observed results with published epidemiology, statistical analysis included age-referred binomial tests and an age-stratified analysis (Cochran-Mantel-Haenszel test). Odds ratios (OR) were also calculated. P<0.05 was considered to indicate locally statistical significance.

RESULTS

In the cancer group, we found a statistically significant reduced rate of diverticula in nearly all age categories and the age-stratified analyses (corresponding OR 0.30-0.51). Consistently, the diverticulitis group revealed a statistically significant decreased rate of advanced colonic neoplastic lesion in nearly all age categories and all age-stratified analyses (corresponding OR 0.13-0.43).

CONCLUSION

Our results indicate that patients with colonic neoplastic lesions or diverticular disease probably form heterogeneous groups. Because current results from molecular biology emphasize the impact of the extracellular matrix on the genesis of diverticulosis and colonic cancer, the observed heterogeneity could be an expression of a distinct composition of the local milieu.

Prevalence and risk of colorectal neoplasia in consumers of alcohol in a screening population

BACKGROUND AND AIMS

Although studies suggest a positive association between alcohol consumption and risk for colorectal neoplasia, the impact on screening has not been fully examined. It is also unclear whether all types of alcohol are associated with an increased risk. We performed a cross-sectional study to examine the impact of regular alcohol consumption on the detection of significant colorectal neoplasia in a screening population.

METHODS

Data collected for 2,291 patients presenting for screening colonoscopy: known risk factors for colorectal neoplasia and alcohol drinking pattern. Our outcome was the endoscopic detection of significant colorectal neoplasia, which included adenocarcinoma, high-grade dysplasia, villous tissue, adenomas 1 cm or greater and multiple (>2) adenomas of any size.

RESULTS

When compared to abstainers, we found an increased risk for significant neoplasia in those patients who consumed more than eight drinks of spirits alcohol (26.3%; OR = 2.53; 95% CI = 1.10-4.28; p < 0.01) and those who drank more than eight servings of beer per week (21.7%; OR = 2.43; 95% CI = 1.11-5.32; p= 0.02). Consuming one to eight glasses of wine per week was associated with a decreased risk for significant neoplasia (OR = 0.55; 95% CI = 0.34-0.87; p < 0.01).

CONCLUSIONS

While there was a more than twofold increased risk of significant colorectal neoplasia in people who drink spirits and beer, people who drank wine had a lower risk. In our sample, people who drank more than eight servings of beer or spirits per week had at least a one in five chance of having significant colorectal neoplasia detected by screening colonoscopy.

Prevalence of advanced colonic polyps in asymptomatic Chinese

AIM: To investigate the prevalence of advanced polyps in asymptomatic Chinese and to determine the risk of proximal advanced colonic polyps in subjects with and without polyps in the distal colon.

METHODS: Data were collected prospectively during colonoscopic examinations performed in 5 973 subjects as part of health evaluation at our unit from December 1997 to December 2003. Polyps were considered advanced, if they were larger than 10 mm or were tubovillous, villous or malignant. Proximal colon was defined as the splenic flexure and more proximal portions of the colon.

RESULTS: Colon polyps were detected in 971 (16.3%) subjects (613 males and 358 females) with their mean age being 56.6 ± 10.7 years. Advanced polyps were noted in 199 (3.3%) individuals. Subjects were sub-classified according to the location of polyps into three groups: distal (569, 58.6%), proximal (284, 29.2%), and combined proximal and distal (118, 12.2%) groups. Subjects with advanced polyps in these three groups were 95 (9.8%), 56 (5.8%), and 48 (4.9%) respectively. In the 48 subjects with advanced combined polyps, 13 advanced polyps were distributed at the distal colon, 17 at the proximal colon, and 18 at both. Eighteen colon cancers including 12 at sigmoid and 6 at ascending colon were confirmed by final pathology. The relative risk for advanced proximal polyp according to distal findings was 3.1 (95%CI: 1.3-7.4) for hyperplastic polyp, 2.7 (95%CI: 1.4-5.3) for tubular polyp and 13.5 (95%CI: 5.1-35.4) for advanced polyp as compared to that for no polyp. However, 56 (28.2%) of 199 subjects with advanced polyps had no index polyps at the distal colon and might go undetected under sigmoidoscopic screening.

CONCLUSION: Although distal lesions can predict the risk of advanced proximal polyps, a substantial portion of Chinese with advanced proximal polyps is not associated with any distal sentinel lesions. These data have implications for screening policy of colon cancers in Taiwanese Chinese.