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

Random forests algorithm using basic medical data for predicting the presence of colonic polyps

Background

Colorectal cancer is considered to be triggered by the malignant transformation of colorectal polyps. Early diagnosis and excision of colorectal polyps has been found to lower the mortality and morbidity associated with colorectal cancer.

Objective

The aim of this study is to offer a predictive model for the presence of colorectal polyps based on Random Forests machine learning algorithm, using basic patient information and common laboratory test results.

Materials and methods

164 patients were included in the study. The following data was collected: sex, residence, age, diabetes mellitus, body mass index, fasting blood glucose levels, hemoglobin, platelets, total, LDL and HLD cholesterol, triglycerides, serum glutamic-oxaloacetic transaminase, chronic gastritis, presence of colonic polyps at colonoscopy. 80% of patients were included in the training set for creating a Random forests algorithm, 20% were in the test set. External validation was performed on data from 42 patients. The performance of the Random Forests was compared with the performance of a generalized linear model (GLM) and support vector machine (SVM) built and tested on the same datasets.

Results

The Random Forest prediction model gave an AUC of 0.820 on the test set. The top five variables in order of importance were: body mass index, platelets, hemoglobin, triglycerides, glutamic-oxaloacetic transaminase. For external validation, the AUC was 0.79. GLM performance in internal validation was an AUC of 0.788, while for external validation AUC-0.65. For SVN, the AUC - 0.785 for internal validation and 0.685 for the external validation dataset.

Conclusions

A random forest prediction model was developed using patient's demographic data, medical history and common blood tests results. This algorithm can foresee, with good predictive power, the presence of colonic polyps.

Representation of Racial Minorities in the United States Colonoscopy Surveillance Interval Guidelines

BACKGROUND/AIMS

Clinical guidelines should ideally be formulated from data representative of the population they are applicable to; however, historically, studies have disproportionally enrolled non-Hispanic White (NHW) patients, leading to potential inequities in care for minority groups. Our study aims to evaluate the extent to which racial minorities were represented in the United States Colorectal Cancer Surveillance Guidelines.

METHODS

We reviewed US guidelines between 1997 and 2020 and all identified studies cited by recommendations for surveillance after a baseline colonoscopy with no polyps, adenomas, sessile serrated polyps, and hyperplastic polyps. We analyzed the proportion of studies reporting race, and among these studies, we calculated the racial distribution of patients and compared the proportion of Non-NHW patients between each subtype.

RESULTS

For all guidelines, we reviewed 75 studies encompassing 9,309,955 patients. Race was reported in 24% of studies and 14% of total patients. Non-NHW comprised 43% of patients in studies for normal colonoscopies, compared with 9% for adenomas, 22% for sessile serrated polyps, and 15% for hyperplastic polyps. For the 2020 guidelines, we reviewed 33 studies encompassing 5,930,722 patients. Race was reported in 15% of studies and 21% of total patients. Non-NHW comprised 43% of patients in studies for normal colonoscopies, compared with 9% for tubular adenomas. Race was not cited for any other 2020 guideline.

CONCLUSION

Racial minorities are significantly underrepresented in US Colorectal Cancer Surveillance Guidelines, which may contribute to disparities in care. Future studies should prioritize enrolling a diverse patient population to provide data that accurately reflects their population.

Colorectal Cancer Risk Perceptions Among Black Men in Florida

PURPOSE

We examined colorectal cancer (CRC) risk perceptions among Black men in relation to socio-demographic characteristics, disease prevention factors, and personal/family history of CRC.

METHODS

A self-administered cross-sectional survey was conducted in five major cities in Florida between April 2008 and October 2009. Descriptive statistics and multivariable logistic regression were performed.

RESULTS

Among 331 eligible men, we found a higher proportion of CRC risk perceptions were exhibited among those aged ≥ 60 years (70.5%) and American nativity (59.1%). Multivariable analyses found men aged ≥ 60 had three times greater odds of having higher CRC risk perceptions compared to those ≤ 49 years (95% CI = 1.51-9.19). The odds of higher CRC risk perception for obese participants were more than four times (95% CI = 1.66-10.00) and overweight were more than twice the odds (95% CI = 1.03-6.31) as compared to healthy weight/underweight participants. Men using the Internet to search for health information also had greater odds of having higher CRC risk perceptions (95% CI = 1.02-4.00). Finally, men with a personal/family history of CRC were ninefold more likely to have higher CRC risk perceptions (95% CI = 2.02-41.79).

CONCLUSION

Higher CRC risk perceptions were associated with older age, being obese/overweight, using the Internet as a health information source, and having a personal/family history of CRC. Culturally resonate health promotion interventions are sorely needed to elevate CRC risk perceptions for increasing intention to screen among Black men.

Risk prediction of advanced colorectal neoplasia varies by race and neighbourhood socioeconomic status

OBJECTIVE

Neighbourhood deprivation increases the risk of colorectal neoplasia and contributes to racial disparities observed in this disease. Developing race-specific advanced colorectal neoplasia (ACN) prediction models that include neighbourhood socioeconomic status has the potential to improve the accuracy of prediction.

METHODS

The study includes 1457 European Americans (EAs) and 936 African Americans (AAs) aged 50-80 years undergoing screening colonoscopy. Race-specific ACN risk prediction models were developed for EAs and AAs, respectively. Area Deprivation Index (ADI), derived from 17 variables of neighbourhood socioeconomic status, was evaluated by adding it to the ACN risk prediction models. Prediction accuracy was evaluated by concordance statistic (C-statistic) for discrimination and Hosmer-Lemeshow goodness-of-fit test for calibration.

RESULTS

With fewer predictors, the EA-specific and AA-specific prediction models had better prediction accuracy in the corresponding race/ethnic subpopulation than the overall model. Compared with the overall model which had poor calibration (P Calibration=0.053 in the whole population and P Calibration=0.011 in AAs), the EA model had C-statistic of 0.655 (95% CI 0.594 to 0.717) and P Calibration=0.663; and the AA model had C-statistic of 0.637 ((95% CI 0.572 to 0.702) and P Calibration=0.810. ADI was a significant predictor of ACN in EAs (OR=1.24 ((95% CI 1.03 to 1.50), P=0.029), but not in AAs (OR=1.07 ((95% CI 0.89 to 1.28), P=0.487). Adding ADI to the EA-specific ACN prediction model substantially improved ACN calibration accuracy of the prediction across area deprivation groups (P Calibration=0.924 with ADI vs P Calibration=0.140 without ADI) in EAs.

CONCLUSIONS

Neighbourhood socioeconomic status is an important factor to consider in ACN risk prediction modeling. Moreover, non-race-specific prediction models have poor generalisability. Race-specific prediction models incorporating neighbourhood socioeconomic factors are needed to improve ACN prediction accuracy.

Colorectal Cancer Incidence in Iran Based on Sex, Age, and Geographical Regions: A Study of 2014-2017 and Projected Rates to 2025

BACKGROUND

While there has been extensive research on colorectal cancer (CRC) incidence and its associated factors in Iran, a significant gap exists in studies predicting its future trends. Our study aimed to thoroughly report CRC incidence across Iran from 2014 to 2017, by sex, age, and geographical regions, and provide a projection for 2025.

METHODS

This retrospective study utilized data from the Iranian National Population-based Cancer Registry (INPCR). Patients with the International Classification of Diseases for Oncology, 3rd Edition (ICD-O-3) codes C18 to C21 were included. The age-standardized incidence rate (ASR), was calculated per 100000 individuals annually, and crude incidence rates were retrieved for various demographic groups and years.

RESULTS

Between 2014 and 2017, a total of 43580 new CRC cases (55.96% males) were registered. Men exhibited an ASR of 134.45, while women's ASR was 94.85. The highest ASRs were observed in Tehran, Qom, and Ilam (18.99, 18.26, and 18.06, respectively). Incidence rates surpassed 20 after age 50 for both genders, reaching their peak within the 80-84 age group. Adenocarcinoma was the most frequent histological type of CRC in nearly all provinces. Case numbers and ASRs are projected to continuously rise until 2025, with a predominance of male cases.

CONCLUSION

The anticipated increase in CRC incidence in Iran emphasizes the need for additional studies to better identify risk factors. Furthermore, implementing screening programs is recommended for individuals at a higher risk of CRC, including men, the elderly population, and those residing in regions with a notable prevalence of CRC.

Geographical Distribution of Colorectal Cancer in Southwestern Iran Between Years 2011 and 2019

BACKGROUND/AIMS

Colorectal cancer is one of the most common cancers in the world. Various genetic, individual, and environmental factors are associated with this disease. Today, the role of environmental and geographical factors has been considered. Accordingly, the present study was conducted to determine the cumulative incidence and geographical distribution of colorectal cancer in Khuzestan province.

MATERIALS AND METHODS

This study was performed ecologically to determine the cumulative incidence of colorectal cancer and its geographical distribution in Khuzestan province between 2011 and 2019. The required information was extracted from the cancer registration program of the Ministry of Health and after refinement and replication.

RESULTS

The cumulative incidence of colorectal cancer in Khuzestan province between 2011 and 2019 was estimated at 40.18 per 100 000 people. The highest cumulative incidence was related to Ahvaz city (95.87 per 100 000 people) and the lowest was related to DashtAzadegan city (25.35 per 100 000 people). The highest cumulative incidence of colorectal cancer, based on climate conditions, is in dry geographical areas (63.77 per 100 000 people), based on average annual rainfall, is in areas with an average rainfall of 100-200 mm (66.28 per 100 000 people), and based on land use, belonged to areas with agricultural use (74.57 per 100 000 people).

CONCLUSION

The cumulative incidence of colorectal cancer is relatively high in Khuzestan province. The cumulative incidence of the disease was higher in the central regions of the province than in other regions. Also, based on geographical areas, the cumulative incidence of the disease was higher in areas with arid climates, the average rainfall was 100-200 mm, and in areas with agricultural land use.

Clinical characteristics and risk factors related to polyposis recurrence and advanced neoplasm development among patients with non-hereditary colorectal polyposis

BACKGROUND/AIMS

Patients with more than 10 cumulative polyps might involve a greater genetic risk of colorectal neoplasia development. However, few studies have investigated the risk factors of polyposis recurrence and development of advanced neoplasms among patients with non-hereditary colorectal polyposis.

METHODS

This study included patients (n=855) with 10 or more cumulative polyps diagnosed at Severance Hospital from January 2012 to September 2021. Patients with known genetic mutations related to polyposis, known hereditary polyposis syndromes, insufficient information, total colectomy, and less than 3 years of follow-up were excluded. Finally, 169 patients were included for analysis. We collected clinical data, including colonoscopy surveillance results, and performed Cox regression analyses of risk factors for polyposis recurrence and advanced neoplasm development.

RESULTS

The 169 patients were predominantly male (84.02%), with a mean age of 64.19±9.92 years. The mean number of adenomas on index colonoscopy was 15.33±8.47. Multivariable analysis revealed history of cancer except colon cancer (hazard ratio [HR], 2.23; 95% confidence interval [CI], 1.23-4.01), current smoking (HR, 2.39; 95% CI, 1.17-4.87), and detection of many polyps (≥15) on index colonoscopy (HR, 2.05; 95% CI, 1.21-3.50) were significant risk factors for recurrence of polyposis. We found no statistically significant risk factors for advanced neoplasm development during surveillance among our cohort.

CONCLUSIONS

The presence of many polyps (≥15) on index colonoscopy, history of cancer except colon cancer, and current smoking state were significant risk factors for polyposis recurrence among patients with non-hereditary colorectal polyposis.

[Sex-specific differences in gastroenterological diseases]

Diseases of the gastrointestinal tract present with substantial sex differences that have a potential impact on patient outcome. This fact is not sufficiently addressed either in basic research or in clinical studies. For example, most animal studies utilize male animals. Despite differences in incidence, sex may affect complication rates, prognosis, or therapeutic response. The incidence of gastrointestinal cancers is frequently higher in males, but this observation cannot solely rely on a distinct risk behaviour. Here, differences in immune response and p53 signalling may be factors responsible for this finding. Nevertheless, taking sex differences into account and improving our understanding of relevant mechanisms is crucial and will most likely have a substantial impact on disease outcome. This overview aims to highlight sex differences in the context of various gastroenterological diseases, primarily to enhance awareness. Attention to sex-specific differences is essential to improve individualized treatment.

Gastroenterologist focus of clinical practice affects adenoma detection in screening colonoscopy

Our objective was to determine whether the clinical focus of gastroenterology practice would affect screening colonoscopy quality metrics, specifically adenoma detection (AD). In a retrospective study of screening colonoscopies, gastroenterologists were categorized based on their clinical subspecialty focus into general/motility, hepatology, inflammatory bowel disease (IBD), and interventional endoscopy. The primary outcome was AD with a secondary outcome of adenoma and/or sessile serrated polyp (SSP) detection (AD + SSP). A total of 5271 (male: 49.1%) complete colonoscopies were performed between 2010 and 2020 by 16 gastroenterologists (male: 62.5%, general/motility specialists: 3, hepatologists: 3, IBD specialists: 4, interventional endoscopists: 6). The AD and AD + SSP rate between each specialty focus were 27.5% and 31.0% for general/motility, 31.4% and 35.5% for hepatology, 38.4% and 43.6% for IBD, and 37.5% and 43.2% for interventional endoscopy. In regression analysis, patient's male gender (odds ratios [OR]: 1.81, 95% CI: 1.60-2.05, P < .001), longer withdrawal time (OR: 1.16, 95% CI: 1.14-1.18, P < .001), hepatologist (OR: 1.25, 95% CI: 1.02-1.53, P = .029), IBD subspecialist (OR: 1.60, 95% CI: 1.30-1.98, P < .001), and interventional endoscopist (OR: 1.36, 95% CI: 1.13-1.64, P < .001) were independently associated with AD. Moreover, patient's male gender (OR: 1.64, 95% CI: 1.45-1.85, P < .001), acceptable bowel preparation (OR: 1.29, 95% CI: 1.06-1.56, P = .010), withdrawal time (1.20, 95% CI: 1.18-1.22, P < .001), hepatologist (OR: 1.30, 95% CI: 1.07-1.59, P = .008), IBD subspecialist (OR: 1.72, 95% CI: 1.39-2.12, P < .001), interventional endoscopist (OR: 1.44, 95% CI: 1.20-1.72, P < .001) were independent factors that improved detection of AD + SSP. Subspecialty focus of practice was an important factor in AD rate along with the male gender of the patient, bowel preparation, and withdrawal time.

Predictors for Colorectal Polyps in an Asymptomatic Population Undergoing Medical Check-ups

BACKGROUND

Colorectal cancer primarily arises from colorectal polyps. Early screening and removal is beneficial, especially in asymptomatic populations. This research aimed to reveal the risk factors detected in medical check-ups for colorectal polyps in asymptomatic people.

MATERIALS AND METHODS

Clinical data of 933 asymptomatic people who underwent colonoscopies from May 2014 to December 2021 was analyzed retrospectively. Data included sex, age, colonoscopy findings, polyp pathology, polyp number, and blood test results. The distribution of colorectal lesions was analyzed. Participants were divided into control and polyp groups, adenomatous and non-adenomatous polyp groups, and single and multiple adenoma groups.

RESULTS

Participants' age, proportion of males, carcinoembryonic antigen (CEA), uric acid and glycosylated hemoglobin levels were significantly higher ( P ≤0.05) in the polyp group. Age (>40 y), sex (male), and CEA level (>1.435 ng/mL) were independent risk factors for polyps. CEA, uric acid, carbohydrate antigen 19-9, triglyceride, and total cholesterol levels were significantly higher ( P <0.05) in the adenoma group than in the non-adenomatous group. CEA level (>1.435 ng/mL) was an independent predictor for adenomas ( P <0.05). Participants' age, proportion of males, CEA, glycosylated hemoglobin, and fasting blood glucose levels were significantly higher ( P <0.05) in the multiple adenoma group than in the single group; the high-density lipoprotein cholesterol level was lower ( P <0.05). No independent risk factors were found for the number of adenomas.

CONCLUSIONS

Serum CEA level (>1.435 ng/mL) was independent risk factor for colorectal polyps. It may be conducive to improve discriminative ability of colorectal cancer risk stratification model.

Recurrence rates after piecemeal endoscopic mucosal resection of large colorectal laterally spreading tumors

BACKGROUND

Piecemeal endoscopic mucosal resection (pEMR) is routinely employed for large laterally spreading tumors (LSTs). Recurrence rates following pEMR are still unclear, especially when cap-assisted EMR (EMR-c) is performed. We assessed the recurrence rates and recurrence risk factors post-pEMR for large colorectal LSTs, including both wide-field EMR (WF-EMR) and EMR-c.

METHODS

This was a single-center, retrospective study of consecutive patients who underwent pEMR for colorectal LSTs ≥20 mm at our institution between 2012 and 2020. Patients had a post-resection follow-up period of at least 3 months. A risk factor analysis was carried out using the Cox regression model.

RESULTS

The analysis included 155 pEMR: 51 WF-EMR and 104 EMR-c, with a median lesion size of 30 (range: 20-80) mm and a median endoscopic follow up of 15 (range: 3-76) months. Overall, disease recurrence occurred in 29.0% of cases; there was no significant difference in recurrence rates between WF-EMR and EMR-c. Recurrent lesions were safely managed by endoscopic removal, and at risk analysis lesion size was the only significant risk factor for recurrence (mm; hazard ratio 1.03, 95% confidence interval 1.00-1.06, P=0.02).

CONCLUSIONS

Recurrence of large colorectal LSTs after pEMR occurs in 29% of cases. This rate is mainly dependent on lesion size, and the use of a cap during pEMR has no effect on recurrence. Prospective controlled trials are needed to validate these results.

Low Prevalence of Screen-Detected Colorectal Cancer in an Average-Risk Population: The New Normal

Prior studies have reported the prevalence of colorectal cancer (CRC) in average-risk screening population ages 50-75 to be 0.7%-1.0%.1,2 However, no estimates from studies enrolling individuals undergoing screening colonoscopy have been reported. The experience of ongoing studies enrolling average-risk individuals is that the prevalence rates are substantially lower. A 2020 study from a community-based cohort undergoing CRC screening with fecal immunochemical testing followed by diagnostic colonoscopy reported a CRC prevalence rate of 1.46 per 1000, or 0.15%.3 The aim of our study is to report the screen-detected prevalence of CRC and advanced neoplasia in average-risk asymptomatic individuals from selected academic and community medical centers in the United States, Canada, and Germany and describe associated risk factors.

Epigenome-Wide Study Identifies Epigenetic Outliers in Normal Mucosa of Patients with Colorectal Cancer

Nongenetic predisposition to colorectal cancer continues to be difficult to measure precisely, hampering efforts in targeted prevention and screening. Epigenetic changes in the normal mucosa of patients with colorectal cancer can serve as a tool in predicting colorectal cancer outcomes. We identified epigenetic changes affecting the normal mucosa of patients with colorectal cancer. DNA methylation profiling on normal colon mucosa from 77 patients with colorectal cancer and 68 controls identified a distinct subgroup of normally-appearing mucosa with markedly disrupted DNA methylation at a large number of CpGs, termed as "Outlier Methylation Phenotype" (OMP) and are present in 15 of 77 patients with cancer versus 0 of 68 controls (P < 0.001). Similar findings were also seen in publicly available datasets. Comparison of normal colon mucosa transcription profiles of patients with OMP cancer with those of patients with non-OMP cancer indicates genes whose promoters are hypermethylated in the OMP patients are also transcriptionally downregulated, and that many of the genes most affected are involved in interactions between epithelial cells, the mucus layer, and the microbiome. Analysis of 16S rRNA profiles suggests that normal colon mucosa of OMPs are enriched in bacterial genera associated with colorectal cancer risk, advanced tumor stage, chronic intestinal inflammation, malignant transformation, nosocomial infections, and KRAS mutations. In conclusion, our study identifies an epigenetically distinct OMP group in the normal mucosa of patients with colorectal cancer that is characterized by a disrupted methylome, altered gene expression, and microbial dysbiosis. Prospective studies are needed to determine whether OMP could serve as a biomarker for an elevated epigenetic risk for colorectal cancer development.

PREVENTION RELEVANCE

Our study identifies an epigenetically distinct OMP group in the normal mucosa of patients with colorectal cancer that is characterized by a disrupted methylome, altered gene expression, and microbial dysbiosis. Identification of OMPs in healthy controls and patients with colorectal cancer will lead to prevention and better prognosis, respectively.

Commencing colorectal cancer screening at age 45 years in U.S. racial groups

Screening for colorectal cancer (CRC) is cost-effective for reducing its mortality among the average-risk population. In the US, CRC incidence and mortality differ among racial/ethnic groups, with non-Hispanic Blacks (NHB) and American Indian/Alaska Natives showing highest incidence and mortality and earlier presentation. Since 2005, some professional societies have recommended CRC screening for NHB to commence at 45 years or earlier; this was not implemented due to lack of recommendation from key groups that influence insurance payment coverage. In 2017 the highly influential U.S. Multi-Society Task Force for Colorectal Cancer recommended screening to commence at 45 years for NHB; this recommendation was supplanted by data showing an increase in early-onset CRCs in non-Hispanic Whites approaching the under-50-year rates observed for NHB. Subsequently the American Cancer Society and the USPSTF recommended that the entire average-risk population move to commence CRC screening at 45 years. Implementing screening in 45–49-year-olds has its challenges as younger groups compared with older groups participate less in preventive care. The US had made extensive progress pre-COVID-19 in closing the disparity gap for CRC screening in NHB above age 50 years; implementing screening at younger ages will take ingenuity, foresight, and creative strategy to reach a broader-aged population while preventing widening the screening disparity gap. Approaches such as navigation for non-invasive and minimally invasive CRC screening tests, removal of financial barriers such as co-pays, and complete follow up to abnormal non-invasive screening tests will need to become the norm for broad implementation and success across all racial/ethnic groups.

Examining the Factors That Affect the Diagnosis of Patients with Positive Fecal Occult Blood Test Results

Due to the threat of colorectal cancer (CRC) to health, Taiwan included the fecal occult blood test (FOBT) under preventive health services in 2010. We examined the factors that affect the diagnosis of people with positive FOBT results. Data were retrospectively collected from the CRC screening database. In the model predicting factors that affect the diagnosis of 89,046 people with positive FOBT results, the risks of disease in the CRC group were lower in medical institutions that conducted follow-up examinations in regions such as Northern Taiwan compared to that in Eastern Taiwan (p = 0.013); they were lower in the age group of 50 to 65 years than those in the age group of 71 to 75 years (p < 0.001, p = 0.016), and lower in the outpatient medical units that conducted follow-up examinations than those in the inpatient medical units by 0.565 times (p < 0.001, 95% CI: 0.493−0.647). Factors affecting the diagnosis of patients with positive FOBT results were gender, the region of the medical institution, medical unit for follow-up examinations, age, screening site, family history, type of follow-up examinations, and follow-up time. Therefore, the identification of characteristics of patients with positive FOBT results and the promotion of follow-up examination are important prevention strategies for CRC.

Predictors of Incident Serrated Polyps: Results from a Large Multicenter Clinical Trial

BACKGROUND

Serrated polyps (SP) are important colorectal cancer precursors, yet their epidemiology is incompletely understood. We measured risk factors for incident sessile-serrated lesions (SSL) and microvesicular (MVHP) and goblet-cell rich (GCHP) hyperplastic polyp subtypes.

METHODS

We conducted a cohort study of patients undergoing colonoscopic surveillance nested within a chemoprevention trial. Outcomes of interest were ≥1 SPs, including SSLs, MVHPs, and GCHPs specifically. Multivariable generalized estimating equation models were used to estimate adjusted risk ratios (RR) and 95% confidence intervals (CI) for different polyp types.

RESULTS

Among 2,102 participants, a total of 1,615 SPs (including 212 SSLs) were found among 758 participants during follow-up. Prior history of SPs was strongly associated with subsequent occurrence of SPs. There was no apparent association between age, sex, or education and risk of SPs. Black participants were at lower risk of SSLs and MVHPs, but higher risk of GCHPs compared with white participants [RR, 0.40; 95% CI, 0.16-0.99); RR, 0.63 (95% CI, 0.42-0.96); and RR, 1.83 (95% CI, 1.23-2.72) respectively]. Alcohol and smoking exposure were also associated with SPs, including hyperplastic polyp subtypes in particular.

CONCLUSIONS

In this prospective study, the risk of SP subtypes differed by race, alcohol, and smoking status, and prior history of SPs. Risk factor associations for SPs differ from risk factors for conventional adenomas, supporting the concept of etiologic heterogeneity of colorectal cancer.

IMPACT

These findings allow for better risk stratification of patients undergoing colorectal cancer screening and could inform screening test selection.

Serrated Colorectal Lesions: An Up-to-Date Review from Histological Pattern to Molecular Pathogenesis

Until 2010, colorectal serrated lesions were generally considered as harmless lesions and reported as hyperplastic polyps (HPs) by pathologists and gastroenterologists. However, recent evidence showed that they may bear the potential to develop into colorectal carcinoma (CRC). Therefore, the World Health Organization (WHO) classification has identified four categories of serrated lesions: hyperplastic polyps (HPs), sessile serrated lesions (SSLs), traditional serrated adenoma (TSAs) and unclassified serrated adenomas. SSLs with dysplasia and TSAs are the most common precursors of CRC. CRCs arising from serrated lesions originate via two different molecular pathways, namely sporadic microsatellite instability (MSI) and the CpG island methylator phenotype (CIMP), the latter being considered as the major mechanism that drives the serrated pathway towards CRC. Unlike CRCs arising through the adenoma-carcinoma pathway, APC-inactivating mutations are rarely shown in the serrated neoplasia pathway.

Risk Factors for Colorectal Polyps and Cancer

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

Prediction Model Using Readily Available Clinical Data for Colorectal Cancer in Chinese Population

BACKGROUND

In China, health screening has become common, although colonoscopy is not always available or acceptable. We sought to develop a prediction model of colorectal cancer (CRC) for health screening population based on readily available clinical data to reduce labor and economic costs.

METHODS

We conducted a cross-sectional study based on a health screening population in Karamay Central Hospital. By collecting clinical data and basic information from participants, we identified independent risk factors and established a prediction model of CRC. Internal and external validation, calibration plot, and decision curve analysis were employed to test discriminating ability, calibration ability, and clinical practicability.

RESULTS

Independent risk factors of CRC, which were readily available in basic public health institutions, included high-density lipoprotein cholesterol, male sex, total cholesterol, advanced age, and hemoglobin. These factors were successfully incorporated into the prediction model (AUC 0.740, 95% CI 0.713-0.767). The model demonstrated a high degree of discrimination and calibration, in addition to a high degree of clinical practicability in high-risk people.

CONCLUSIONS

The prediction model exhibits good discrimination and calibration and is pragmatic for CRC screening in rural areas and basic public health institutions.

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

GOAL

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

STUDY

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

RESULTS

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

CONCLUSIONS

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

Association Between the Sulfur Microbial Diet and Risk of Colorectal Cancer

IMPORTANCE

Sulfur-metabolizing bacteria that reduce dietary sulfur to hydrogen sulfide have been associated with colorectal cancer (CRC). However, there are limited studies investigating the association between diet and sulfur-metabolizing bacteria in the development of CRC.

OBJECTIVE

To develop a dietary score that correlates with gut sulfur-metabolizing bacteria and to examine its association with CRC risk.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included data from the Health Professionals Follow-up Study (1986-2014), Nurses' Health Study (1984-2016), and Nurses' Health Study II (1991-2017). Participants were US male health professionals and female registered nurses who were free of inflammatory bowel disease and cancer at baseline, with a subsample of participants who provided stool samples from 2012 to 2014. Statistical analysis was conducted from September 1, 2020, to June 1, 2021.

EXPOSURE

A dietary pattern, assessed by a food-frequency questionnaire, that most correlated with 43 sulfur-metabolizing bacteria identified through taxonomic and functional profiling of gut metagenome data.

MAIN OUTCOMES AND MEASURES

Incident CRC.

RESULTS

Among 214 797 participants comprising 46 550 men (mean [SD] age at baseline, 54.3 [9.7] years) and 168 247 women (mean [SD] age at baseline, 43.0 [9.2] years), 3217 incident cases of CRC (1.5%) were documented during 5 278 048 person-years of follow-up. The sulfur microbial diet, developed in a subsample of 307 men (mean [SD] age, 70.5 [4.3] years) and 212 women (mean [SD] age, 61.0 [3.8] years), was characterized by high intakes of low-calorie beverages, french fries, red meats, and processed meats and low intakes of fruits, yellow vegetables, whole grains, legumes, leafy vegetables, and cruciferous vegetables. After adjustment for other risk factors, greater adherence to the sulfur microbial diet was associated with an increased risk of CRC, with a hazard ratio (HR) of 1.27 (95% CI, 1.12-1.44) comparing the highest vs the lowest quintile of the diet score (linear trend of diet score quintiles; P < .001 for trend). When assessed by anatomical subsites, greater adherence to the sulfur microbial diet was positively associated with distal CRC (HR, 1.25; 95% CI, 1.05-1.50; P = .02 for trend) but not proximal colon cancer (HR, 1.13; 95% CI, 0.93-1.39; P = .19 for trend).

CONCLUSIONS AND RELEVANCE

Adherence to the sulfur microbial diet was associated with an increased risk of CRC, suggesting a potential mediating role of sulfur-metabolizing bacteria in the associaton between diet and CRC. Further research is needed to confirm these findings and to determine the underlying mechanisms.

EVALUATION OF UNDERWATER ENDOSCOPIC MUCOSAL RESECTION FOR COLORECTAL POLYPS IN AN OUTPATIENT CLINIC IN BRAZIL

BACKGROUND

Since 2012, a new technique for resection of large polyps has been described, the underwater endoscopic mucosal resection (UEMR). Some advantages that emerge from it is the needless of injection in submucosal layer and a greater chance of complete capture of the polyp.

OBJECTIVE

There are few studies of UEMR in Brazil. The aim of this study is to evaluate the safety and efficacy of this technique in one Brazilian center.

METHODS

This case series was conducted from February to December of 2020. Colorectal polyps greater than 9 mm without features of deep submucosal invasion were resected using UEMR.

RESULTS

Twenty-four large polyps were resected with the UEMR approach from 24 patients. The mean size of the polys was 19 mm, ranging from 12 to 35 mm. All lesions were successful resected and 66% (16/24) were resected en bloc. In histologic analyses, most of them were adenomas (70.8%) and only one had deep submucosal invasion. There were no cases of acute complications, such perforation or acute bleeding.

CONCLUSION

The UEMR is a safe and feasible procedure. With the emerging data on the procedure, it seems to be a wonderful tool in preventing colorectal cancer and its applicability and scope should be encourage to surpass reference centers.

Short-term aspirin and statin chemoprophylaxis did not reduce the risk of developing advanced adenomatous polyps in Black patients

BACKGROUND

Chemoprevention of colorectal neoplasia with aspirin and statins is under-investigated in Black patients. Since Black patients suffer disproportionately from colon cancer incidence and mortality compared to other populations, we investigated the utility of aspirin and statin in reducing advanced adenomatous polyp (AAP) risk in Black patients.

METHODS

We carried out a retrospective cohort study of screening colonoscopies performed at a large urban academic center from 1/1/2011 through 12/31/2019. We analyzed self-identified Black patients with > 1 colonoscopy and no personal history of either inflammatory bowel disease or colon cancer syndromes. Our primary endpoint was first AAP development after index colonoscopy among Black patients taking both aspirin and a statin compared to those taking one or neither medication. We used multivariate logistic regression modeling to investigate our outcomes.

RESULTS

We found data on chemoprophylaxis use in 560 patients. The mean observation period between index colonoscopy and AAP identification was 4 years. AAP developed in 106/560 (19%) of our cohort. We found no difference in AAP risk among Black patients taking both chemoprevention medications compared to partial or no chemoprophylaxis (20% vs 18% respectively, p = 0.49). This finding remained after adjusting for age, body mass index, and tobacco use (odds ratio 1.04, 95% CI 0.65-1.67; p = 0.87).

CONCLUSIONS

Short-term aspirin-statin chemoprevention did not reduce the risk of AAP development in our cohort of Black patients. Larger and long-term prospective investigations are needed to investigate the utility of chemoprophylaxis in this population.

TRIAL REGISTRATION

Not applicable.

Detection of Colon Polyps in India—A Large Retrospective Cohort Study (DoCPIr)

Objective Colorectal cancer (CRC) is an emerging public health problem in Asia and India. However, there is scarcity of data on CRC and adenoma. We aimed to study prevalence and characteristics of colonic polyps in a large retrospective cohort.

Methods For this retrospective single center study, all patients with age > 18 years undergoing colonoscopy from January 2018 to December 2019 were included. Age, gender, and polyp characteristics were collected from endoscopy and histology database. Patients with incomplete histology reports and anal canal polyps were excluded. Based on histology, polyps were divided into adenocarcinoma, adenoma with advanced pathology (AAP; size > 10 mm, villous morphology or high-grade dysplasia), nonadvanced adenomas (nAAP), and nonadenomas.

Results Overall colon polyp prevalence was 10.18% (3551/34893). The mean age (standard deviation [SD]) was 51.51 (14.84) with 75.4% males, of which 128 (3.6%) were adenocarcinoma. A total of 1514 (42.64%) were adenomas; 344 (9.7%) were AAP and 1170 (32.9%) were nAAP. The remaining 1909 (53.8%) were nonadenomas. Colonic adenoma prevalence after excluding adenocarcinoma was 4.35% (1514/34893). Adenocarcinoma (68.8% vs. 31.2%), AAP (70.6% vs. 29.4%), other adenomas (75.4% vs. 24.6%), and nonadenomas (76.7% vs. 23.3%) were significantly higher in male compared with female (p < 0.05). Adenomas and adenocarcinomas were more common in left colon and rectum than right colon (p < 0.05). The mean age (SD) were significantly lower in nonadenomas than adenocarcinomas, AAP, and other adenomas (p 0.0001; 49.25 [14.84] vs. 55.97 [12.47], 54.78 [16.40], 53.76 [13.71]).

Conclusions The prevalence of colonic adenoma in India is 4.35%. Male gender and increased age were associated with increased risk of colonic adenoma and adenocarcinoma, which is more common in left colon and rectum. Prospective multicenter studies are required for evaluation of other risk factors of CRC and colonic adenomas.

Increasing changes in visceral adiposity is associated with higher risk for colorectal adenoma: Multilevel analysis in a prospective cohort

BACKGROUND AND AIM

While many studies demonstrated an association between visceral adiposity and colorectal adenoma (CRA), the effect of longitudinal changes in body fat composition on CRA is unclear. We investigated the longitudinal association between changes in visceral adiposity and CRA occurrence.

METHODS

Between 2006 and 2018, 732 (62.8%) of the 1165 subjects in a prospective cohort voluntarily underwent follow-up abdominal fat computed tomography and colonoscopy. We defined incident and recurrent CRA as adenoma detected at follow-up colonoscopy from negative and positive adenoma at baseline colonoscopy, respectively. Multilevel survival analysis examined the longitudinal association between changes in visceral fat and CRA.

RESULTS

During a median follow-up of 7.4 years, 400 (54.6%) subjects developed CRA. In multivariable analysis, increasing changes in visceral adipose tissue (VAT) area were associated with higher risk of incident adenoma (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.00-1.46 for change per 10 cm2 increase; HR 1.79, 95% CI 1.08-2.97 for highest vs lowest quartile, P values for trend = 0.045). Likewise, increasing changes in VAT area were independently associated with a higher risk of recurrent adenoma (HR 1.35, 95% CI 1.13-1.62 for change per 10 cm2 increase; HR 1.62, 95% CI 1.04-2.52 for highest vs lowest quartile, P values for trend = 0.001). Changes in subcutaneous adipose tissue area were not independently associated with CRA.

CONCLUSION

Increasing changes in VAT area were longitudinally associated with a higher risk of incident and recurrent CRA, independent of risk factors, suggesting that visceral adiposity may be an important target in CRA prevention.

Racial and ethnic disparities in colorectal cancer incidence and mortality

The occurrence of colorectal cancer (CRC) shows a large disparity among recognized races and ethnicities in the U.S., with Black Americans demonstrating the highest incidence and mortality from this disease. Contributors for the observed CRC disparity appear to be multifactorial and consequential that may be initiated by structured societal issues (e.g., low socioeconomic status and lack of adequate health insurance) that facilitate abnormal environmental factors (through use of tobacco and alcohol, and poor diet composition that modifies one's metabolism, microbiome and local immune microenvironment) and trigger cancer-specific immune and genetic changes (e.g., localized inflammation and somatic driver gene mutations). Mitigating the disparity by prevention through CRC screening has been demonstrated; this has not been adequately shown once CRC has developed. Acquiring additional knowledge into the science behind the observed disparity will inform approaches towards abating both the incidence and mortality of CRC between U.S. racial and ethnic groups.

Histopathological and epidemiological findings of colonoscopy screening in a population with an average risk of colorectal cancer in Kuwait

BACKGROUND

Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men worldwide, with a significantly rising incidence in the Middle East region over the last few decades. This study investigates the histopathological and epidemiological characteristics of colonoscopic findings in a population with an average risk of CRC in Kuwait.

METHODS

In this study, 1,005 asymptomatic average-risk Kuwaiti adults aged over 40 years had their first colonoscopy screening during the 2015-2018 period. Data on lifestyle behaviors (cigarette smoking, alcohol consumption, and physical activity), body mass index (BMI), and comorbidities were routinely collected from these individuals. All colorectal polyps or masses were assessed for their site, size, and number and then resected and sent for histopathological examination.

RESULTS

The mean age of the participants was 54 years, and 52.2% were women. In screened individuals, the polyp detection rate, adenoma detection rate, and carcinoma detection rate were 43.8%, 27.7%, and 1.2%, respectively. Tubular, tubulovillous, and villous types of adenoma constituted 17.3%, 2.8%, and 1.3% of all screened participants. Neoplastic lesions, particularly in the proximal colon, were more common among men aged 40-49 years. Age of 70 years and older (OR: 9.6; 95% CI: 4.7-19.9; P < 0.001), male gender (OR: 1.6; 95% CI: 1.1-2.3; P = 0.011), increased BMI (OR: 1.05; 95% CI: 1.02-1.08; P = 0.001), and smoking (OR: 3.5; 95% CI: 2.3-5.4; P < 0.001) were the most significant independent risk factors for colorectal neoplasia.

CONCLUSIONS

The high adenoma detection rate (ADR) in Kuwaiti population calls for the establishment of a national programe for CRC screening. The higher ADR in those younger than 50 years calls for assessment of the threshold age at which to start screening.

Community Health Behaviors and Geographic Variation in Early-Onset Colorectal Cancer Survival Among Women

INTRODUCTION

Despite overall reductions in colorectal cancer (CRC) morbidity and mortality, survival disparities by sex persist among young patients (age <50 years). Our study sought to quantify variance in early-onset CRC survival accounted for by individual/community-level characteristics among a population-based cohort of US women.

METHODS

Geographic hot spots-counties with high early-onset CRC mortality rates among women-were derived using 3 geospatial autocorrelation approaches with Centers for Disease Control and Prevention national mortality data. We identified women (age: 15-49 years) diagnosed with CRC from 1999 to 2016 in the National Institutes of Health/National Cancer Institute's Surveillance, Epidemiology, and End Results program. Patterns of community health behaviors by hot spot classification were assessed by Spearman correlation (ρ). Generalized R values were used to evaluate variance in survival attributed to individual/community-level features.

RESULTS

Approximately 1 in every 16 contiguous US counties identified as hot spots (191 of 3,108), and 52.9% of hot spot counties (n = 101) were located in the South. Among 28,790 women with early-onset CRC, 13.7% of cases (n = 3,954) resided in hot spot counties. Physical inactivity and fertility were community health behaviors that modestly correlated with hot spot residence among women with early-onset CRC (ρ = 0.21 and ρ = -0.23, respectively; P < 0.01). Together, individual/community-level features accounted for distinct variance patterns in early-onset CRC survival among women (hot spot counties: 33.8%; non-hot spot counties: 34.1%).

DISCUSSION

Individual/community-level features accounted for approximately one-third of variation in early-onset CRC survival among women and differed between hot spot vs non-hot spot counties. Understanding the impact of community health behaviors-particularly in regions with high early-onset CRC mortality rates-is critical for tailoring strategies to reduce early-onset CRC disparities.

Effect of referral pattern and histopathology grade on surgery for nonmalignant colorectal polyps

BACKGROUND AND AIMS

The incidence of surgery for nonmalignant colorectal polyps is rising. The aims of this study were to evaluate referral patterns to surgery for nonmalignant polyps, to compare outcomes between surgery and endoscopic resection (ER), and to identify factors associated with surgery in a university-based, tertiary care center.

METHODS

Patients referred to colorectal surgery (CRS) for nonmalignant colorectal polyps between 2014 and 2019 were selected from the institution's integrated data repository. Clinical characteristics were obtained through chart review. Multivariate analysis was performed to identify factors associated with surgery for nonmalignant polyps.

RESULTS

Six hundred sixty-four patients with colorectal lesions were referred to CRS, of which 315 were for nonmalignant polyps. Most referrals (69%) came from gastroenterologists. Of the 315 cases, 136 underwent surgery and 117 were referred for attempt at ER. Complete ER was achieved in 87.2% (n = 102), with polyp recurrence in 27.2% at a median of 14 months (range, 0-72). When compared with surgery, ER was associated with a lower hospitalization rate (22.2% vs 95.6%; P < .0001), shorter hospital stay (mean, .5 ± .9 vs 2.23 ± 1 days; P < .0001), and fewer adverse events (5.9% vs 22.8%; P = .0002). Intramucosal adenocarcinoma on baseline pathology (odds ratio, 5.7; 95% confidence interval, 1.2-28.2) and referrals by academic gastroenterologists (odds ratio, 2.5; 95% confidence interval, 1.11-5.72) were associated with a higher likelihood of surgery on multivariate analysis.

CONCLUSIONS

Gastroenterologists commonly refer nonmalignant colorectal polyps to surgery, even though ER is effective and associated with lower morbidity. Both referrals from academic gastroenterologists and baseline pathology of intramucosal adenocarcinoma were factors associated with surgery. All colorectal polyps should be evaluated in a multidisciplinary approach to identify lesions suitable for ER before embarking in surgery.

Elevated Risk for Sessile Serrated Polyps in African Americans with Endometrial Polyps

BACKGROUND

Colorectal and endometrial lesions increase with age. It is not known if these two precursor lesions in sporadic cases associate with each other.

AIM

To determine the association between colorectal polyps and endometrial polyps (EP) in African Americans.

METHODS

We reviewed records of patients referred to gynecology clinics and had colonoscopy at Howard University Hospital from January 2004 to December 2015. We defined cases as all patients who had EP and underwent colonoscopy. For controls, we used EP-free patients who underwent colonoscopy. Logistic regression analysis was used to assess the association between colon polyps and EP.

RESULTS

The median age was 60 years in 118 Cases and 57 years in 664 Controls. The overall colorectal polyps prevalence in the two groups was not statistically different (54% in controls vs. 52% in cases, P = 0.60). Sessile serrated adenoma/polyps (SSPs) were more frequent in cases (8% vs. 2% in controls, P = 0.003). Sigmoid and rectal locations were more prevalent in controls than cases. In multivariate analysis and after adjusting for age, diabetes mellitus (DM), and BMI, SSPs were associated with EP occurrence with an odds ratio of 4.6 (CI 1.2-16.7, P = 0.022).

CONCLUSION

Colorectal polyp prevalence was similar in EP patients compared to EP-free controls. However, we observed a significant association between higher-risk SSPs in patients with EP. The prevalence of smoking and DM was higher in these patients. Females with EP might benefit from a screening for colonic lesions in an age-independent manner.

Common Urinary and Bowel Disorders in the Geriatric Population

The prevalence of urinary incontinence and other lower urinary tract symptoms increases with older age. These symptoms are more noticeable in men after the seventh decade of life and in women after menopause. Constipation and fecal incontinence are major causes of symptoms in elderly patients and can significantly impair quality of life. This article summarizes the current literature regarding the occurrence and implications of lower urinary tract and bowel symptoms in the geriatric population.

Gastrointestinal endoscopy nurse assistance during colonoscopy and polyp detection: A PRISMA-compliant meta-analysis of randomized control trials

BACKGROUND

Previous studies showed difference results about the effect of nurse in improvement of the colonoscopy detection rate. This meta-analysis aims to investigate whether nurse participation during colonoscopy can help in improving the detection rate of polyps and adenomas.

METHODS

Original studies in English were searched from the MEDLINE database, PubMed, Web of Science, and the Cochrane Library database. Randomized control trials (RCT) comparing colonoscopy with and without nurse participation for the detection of colorectal polyps and adenomas were identified. A meta-analysis was performed using Revman 5.3 software.

RESULTS

A total of 2268 patients from 4 RCTs were included in this meta-analysis. Outcomes of colonoscopy with nurse participation were compared with those of colonoscopy without nurse participation. The results showed that nurses' participation during colonoscopy could significantly increase both, polyp detection rate and adenoma detection rate.

CONCLUSION

Nurse assistance during colonoscopy can help improve the rate of detection of polyps and adenomas.

Sex and Race Disparities in Diverticulosis Prevalence

BACKGROUND & AIMS

The prevalence of diverticulosis differs with demographic features of patients, but evidence is limited. Well-defined demographic studies are necessary to understand diverticulosis biology. We estimated the prevalence of diverticulosis among patients of different ages, sexes, and races and ethnicities and calculated odds ratios.

DESIGN

Using data from an endoscopic database, we identified 271,181 colonoscopy procedures performed from 2000 through 2012 at 107 sites in the United States. Our analysis included individuals 40 years and older who underwent colonoscopy examination for average-risk screening. The outcome was any reported diverticulosis on colonoscopy. Multivariate analyses were performed using logistic regression to estimate odds ratios (ORs) and 95% CI values, adjusting for confounding variables.

RESULTS

The prevalence of diverticulosis increased with age in men and women of all races and ethnicities. Women 40-49 years old had significantly lower odds of any diverticulosis (OR, 0.71; 95% CI, 0.63-0.80) compared with men 40-49 years old, after adjustment. The strength of this association decreased with age. Compared with non-Hispanic white individuals, non-Hispanic black individuals (OR, 0.80; 95% CI, 0.77-0.83) and Asian/Pacific Islanders (OR, 0.38; 95% CI, 0.35-0.41) had lower odds of any diverticulosis. However, non-Hispanic black individuals (OR, 1.53, 95% CI, 1.44-1.62) had increased odds of any proximal diverticulosis, whereas Asian/Pacific Islanders (OR, 3.12; 95% CI, 2.67-3.66) had increased odds of only proximal diverticulosis.

CONCLUSIONS

In an analysis of data from 271,181 colonoscopy procedures, diverticulosis was less prevalent in women compared with men in the same age groups, indicating that sex hormones might affect pathogenesis. Differences in the odds of diverticulosis by race and ethnicity indicate a genetic contribution to risk.

Afro-Caribbeans Have a Lower Prevalence of Advanced Colon Neoplasia than African-Americans

BACKGROUND/AIMS

The black population in the USA is a heterogeneous group composed of smaller subgroups from different origins. The definition of black in many colorectal cancer (CRC) risk studies is vague, and differences in CRC risk comparing black subpopulations have not been evaluated. The aim of the study is to compare advanced colorectal neoplasia (ACN) between two subgroups of black populations: African-American (AA) and Afro-Caribbean (AC). A secondary aim was to determine whether there are differences in prevalence of adenomas.

METHODS

This was a retrospective study of 3797 AA and AC patients undergoing first time screening colonoscopy in two different institutions in the USA.

RESULTS

Overall adenoma prevalence was 29.3% for the entire population with 29.5% in AAs and 29.0% in AC with no statistically significant difference between the study groups (AOR: 1.02; 95% CI 0.88-1.18, P = 0.751). However, ACN was significantly higher in the AA group (11.8%) compared to AC (9.0%) (AOR: 1.30, 95% CI 1.02-1.66, P = 0.034). It was observed that AAs had ACN at a higher BMI than AC. After adjusting for BMI/ethnicity interactions, the difference in ACN between both groups became more significant (AOR: 1.93, 95% CI 1.16-3.23, P = 0.012).

CONCLUSIONS

AAs have a higher risk of ACN than AC. Current recommendations to start screening in average-risk AAs at an earlier age may not apply to other black subgroups.

A User-Friendly, Web-Based Integrative Tool (ESurv) for Survival Analysis: Development and Validation Study

BACKGROUND

Prognostic genes or gene signatures have been widely used to predict patient survival and aid in making decisions pertaining to therapeutic actions. Although some web-based survival analysis tools have been developed, they have several limitations.

OBJECTIVE

Taking these limitations into account, we developed ESurv (Easy, Effective, and Excellent Survival analysis tool), a web-based tool that can perform advanced survival analyses using user-derived data or data from The Cancer Genome Atlas (TCGA). Users can conduct univariate analyses and grouped variable selections using multiomics data from TCGA.

METHODS

We used R to code survival analyses based on multiomics data from TCGA. To perform these analyses, we excluded patients and genes that had insufficient information. Clinical variables were classified as 0 and 1 when there were two categories (for example, chemotherapy: no or yes), and dummy variables were used where features had 3 or more outcomes (for example, with respect to laterality: right, left, or bilateral).

RESULTS

Through univariate analyses, ESurv can identify the prognostic significance for single genes using the survival curve (median or optimal cutoff), area under the curve (AUC) with C statistics, and receiver operating characteristics (ROC). Users can obtain prognostic variable signatures based on multiomics data from clinical variables or grouped variable selections (lasso, elastic net regularization, and network-regularized high-dimensional Cox-regression) and select the same outputs as above. In addition, users can create custom gene signatures for specific cancers using various genes of interest. One of the most important functions of ESurv is that users can perform all survival analyses using their own data.

CONCLUSIONS

Using advanced statistical techniques suitable for high-dimensional data, including genetic data, and integrated survival analysis, ESurv overcomes the limitations of previous web-based tools and will help biomedical researchers easily perform complex survival analyses.

Molecular Aspects of Colorectal Adenomas: The Interplay among Microenvironment, Oxidative Stress, and Predisposition

The development of colorectal cancer (CRC) is a multistep process initiated by a benign polyp that has the potential to evolve into in situ carcinoma through the interactions between environmental and genetic factors. CRC incidence rates are constantly increased for young adult patients presenting an advanced tumor stage. The majority of CRCs arise from colonic adenomas originating from aberrant cell proliferation of colon epithelium. Endoscopic polypectomy represents a tool for early detection and removal of polyps, although the occurrence of cancers after negative colonoscopy shows a significant incidence. It has long been recognized that the aberrant regulation of Wingless/It (Wnt)/β-Catenin signaling in the pathogenesis of colorectal cancer is supported by its critical role in the differentiation of stem cells in intestinal crypts and in the maintenance of intestinal homeostasis. For this review, we will focus on the development of adenomatous polyps through the interplay between renewal signaling in the colon epithelium and reactive oxygen species (ROS) production. The current knowledge of molecular pathology allows us to deepen the relationships between oxidative stress and other risk factors as lifestyle, microbiota, and predisposition. We underline that the chronic inflammation and ROS production in the colon epithelium can impair the Wnt/β-catenin and/or base excision repair (BER) pathways and predispose to polyp development. In fact, the coexistence of oxidative DNA damage and errors in DNA polymerase can foster C>T transitions in various types of cancer and adenomas, leading to a hypermutated phenotype of tumor cells. Moreover, the function of Adenomatous Polyposis Coli (APC) protein in regulating DNA repair is very important as therapeutic implication making DNA damaging chemotherapeutic agents more effective in CRC cells that tend to accumulate mutations. Additional studies will determine whether approaches based on Wnt inhibition would provide long-term therapeutic value in CRC, but it is clear that APC disruption plays a central role in driving and maintaining tumorigenesis.

Colorectal Cancer in the Young: Epidemiology, Prevention, Management

Colorectal cancer (CRC) incidence rates in the United States overall have declined since the mid-1980s because of changing patterns in risk factors (e.g., decreased smoking) and increases in screening. However, this progress is increasingly confined to older adults. CRC occurrence has been on the rise in patients younger than age 50, often referred to as early-onset disease, since the mid-1990s. Young patients are more often diagnosed at an advanced stage and with rectal disease than their older counterparts, and they have numerous other unique challenges across the cancer management continuum. For example, young patients are less likely than older patients to have a usual source of health care; often need a more complex treatment protocol to preserve fertility and sexual function; are at higher risk of long-term and late effects, including subsequent primary malignancies; and more often suffer medical financial hardship. Diagnosis is often delayed because of provider- and patient-related factors, and clinicians must have a high index of suspicion if young patients present with rectal bleeding or changes in bowel habits. Educating primary care providers and the larger population on the increasing incidence and characteristic symptoms is paramount. Morbidity can further be averted by increasing awareness of the criteria for early screening, which include a family history of CRC or polyps and a genetic predisposition.

Causes of Socioeconomic Disparities in Colorectal Cancer and Intervention Framework and Strategies

Colorectal cancer (CRC) disproportionately affects people from low socioeconomic backgrounds and some racial minorities. Disparities in CRC incidence and outcomes might result from differences in exposure to risk factors such as unhealthy diet and sedentary lifestyle; limited access to risk-reducing behaviors such as chemoprevention, screening, and follow-up of abnormal test results; or lack of access to high-quality treatment resources. These factors operate at the individual, provider, health system, community, and policy levels to perpetuate CRC disparities. However, CRC disparities can be eliminated. Addressing the complex factors that contribute to development and progression of CRC with multicomponent, adaptive interventions, at multiple levels of the care continuum, can reduce gaps in mortality. These might be addressed with a combination of health care and community-based interventions and policy changes that promote healthy behaviors and ensure access to high-quality and effective measures for CRC prevention, diagnosis, and treatment. Improving resources and coordinating efforts in communities where people of low socioeconomic status live and work would increase access to evidence-based interventions. Research is also needed to understand the role and potential mechanisms by which factors in diet, intestinal microbiome, and/or inflammation contribute to differences in colorectal carcinogenesis. Studies of large cohorts with diverse populations are needed to identify epidemiologic and molecular factors that contribute to CRC development in different populations.

Screening for Colon Cancer in Older Adults: Risks, Benefits, and When to Stop

Colorectal cancer (CRC) is the fourth leading cause of cancer and second leading cause of mortality from cancer in the United States. As the population ages, decisions regarding the initiation and cessation of screening and surveillance for CRC are of increasing importance. In elderly patients, the risks of CRC and the presenting signs and symptoms are similar to those in younger patients. Screening and ongoing surveillance should be considered in patients who have a life expectancy of 10 years or more. Life expectancy estimates can be calculated using online calculators. If screening is deemed appropriate, the choice of which test to use first is unclear. Currently, there are a number of modalities available to screen for CRC, including both invasive modalities (eg, colonoscopy, sigmoidoscopy, capsule colonoscopy, and computed tomographic colonography) and noninvasive modalities (fecal immunochemical test, stool DNA testing, and blood testing). Colonoscopy and other invasive testing options are considered safe, but the risks of complications of the bowel preparation, the procedure, and sedation medications are all increased in older patients. In contrast, noninvasive testing provides a safe initial test; however, it is important to consider the increased false-positive rates in the elderly, and a positive test result will usually necessitate colonoscopy to establish the diagnosis. Ongoing screening and surveillance should be a shared decision-making process with the patient based on multiple factors including the patient's morbidity and mortality risk from CRC and his or her underlying comorbidities, the patient's functional status, and the patient's preferences for screening. Ultimately, the decision to initiate or discontinue screening for CRC in older patients should be done based on a case-by-case individualized discussion.

Potential Prognostic and Diagnostic Values of CDC6, CDC45, ORC6 and SNHG7 in Colorectal Cancer

Background

Colorectal cancer (CRC) is a common human malignancy. The aims of this study are to investigate the gene expression profile of CRC and to explore potential strategy for CRC diagnosis, therapy and prognosis.

Methods

We use affy and Limma package of Bioconductor R to do differential expression genes (DEGs) and differential expression lncRNAs (DELs) analysis from the gene datasets (GSE8671, GSE21510, GSE32323, GSE39582 and TCGA) respectively. Then, DEGs were analyzed by GO and KEGG pathway and Kaplan-Meier survival curve and Cox regression analyses were used to find aberrantly expressed genes associated with survival outcome of CRC patients. Real-time PCR assay was used to verify the aberrantly expressed genes expression in CRC samples.

Results

306 up-regulation and 213 down-regulation common DEGs were found. A total of 485 DELs were identified, of which 241 up-regulated and 244 down-regulated. Then, GO and KEGG pathway analyses showed that DEGs were involved in cell cycle, mineral absorption, DNA replication, and Nitrogen metabolism. Among them, Kaplan-Meier survival curve and Cox regression analyses revealed that CDC6, CDC45, ORC6 and SNHG7 levels were significantly associated with survival outcome of CRC patients. Finally, real-time PCR assay was used to verify that the CDC6, CDC45, ORC6 and SNHG7 expression were up-regulated in 198 CRC samples compared with the expression levels in individual-matched adjacent mucosa samples.

Conclusion

CDC6, CDC45, ORC6 and SNHG7 are implicated in CRC initiation and progression and could be explored as potential diagnosis, therapy and prognosis targets for CRC.

Sugar-sweetened beverages and colorectal cancer risk in the California Teachers Study

BACKGROUND

The association between sugar-sweetened beverage (SSB) consumption and colorectal cancer (CRC) risk remains unclear and published data are limited.

METHODS

The analytic cohort included 99,798 women, free of cancer at baseline, from the California Teachers Study, a longitudinal cohort comprised of 133,477 female teachers and administrators who were active or recently retired members of the California State Teachers Retirement System in 1995. SSB consumption constituted caloric soft drinks, sweetened bottled waters and teas, and fruit drinks, derived from a self-administered food frequency questionnaire. Consumption was divided into four categories: Rare or never, >rare/never to <1 serving/week, ≥1 serving/week to <1 serving/day, and ≥1 serving/day. CRC endpoints were based on annual linkage with California Cancer Registry, defined as first diagnosis of CRC, and classified following the Surveillance, Epidemiology, and End Results Program coding system. Multivariable-adjusted Cox proportional hazards models were used to generate hazard ratios (HR) and 95% confidence intervals (CI) for assessing the association between SSB consumption and incident CRC.

RESULTS

A total of 1,318 incident CRC cases were identified over 20 years of follow-up (54.5% proximal colon and 45.5% distal colorectum). Compared with rare/never consumers, the multivariable-adjusted HRs (95% CI) were 1.14 (0.86, 1.53) for total CRC; 1.11 (0.73, 1.68) for proximal colon; and 1.22 (0.80, 1.86) for distal colorectum cancers among women consuming ≥ 1 serving/day of SSBs.

CONCLUSION

SSBs were not significantly associated with CRC risk. The biological effects of high SSB consumption make it important to continue to evaluate whether SSBs are associated with CRC. Additionally, future studies should further assess SSBs in large, racial/ethnically diverse cohorts of males and females, and, if feasible, address changes in SSB consumption over time.

Disparities in Utilization of Medical Specialists for Colonoscopy

Purpose: Colonoscopy is the preferred screening modality for colorectal cancer (CRC) prevention. The quality of the procedure varies although medical specialists such as gastroenterologists and colorectal surgeons tend to have better outcomes. We aimed to determine whether there are demographic and clinical differences between those who received a colonoscopy from a specialist versus those who received a colonoscopy from a nonspecialist.

Methods: Using the population-based South Carolina Outpatient Ambulatory Surgery Database, we looked retrospectively to obtain patient-level endoscopy records from 2010 to 2014. We used multilevel logistic regression to model whether patients saw a specialist for their colonoscopy. The primary variables were patient race and insurance type, and an interaction by rurality was tested.

Results: Of the 392,285 patients included in the analysis, 81% saw a specialist for their colonoscopy. County of residence explained 30% of the variability in the outcome. Non-Hispanic black (OR=0.65; confidence interval [95% CI]: 0.64–0.67) and Hispanic patients (OR=0.75; 95% CI: 0.67–0.84) were significantly less likely than non-Hispanic white patients to see a specialist. Compared with commercial/HMO insurance, all other types were less likely to see a specialist, and even more so for rural patients. The interaction of race by rurality was not significant.

Conclusions: Specialists play a key role in CRC screening and can affect later downstream outcomes. This study has shown that ethnic minorities and adults with public or other insurance, particularly in rural areas, are most likely not to see a specialist. These results are consistent with disparities in CRC incidence, mortality, and survival.

Can the rate and location of sessile serrated polyps be part of colorectal Cancer disparity in African Americans?

BACKGROUND

Up to 30% of colorectal cancers develop through the serrated pathway. African Americans (AAs) suffer a disproportionate burden of colorectal cancer. The aim of this study was to evaluate clinicopathological features of AA patients diagnosed with sessile serrated polyps (SSPs).

METHODS

We conducted a retrospective study of all colonoscopies (n = 12,085) performed at Howard University Hospital, from January 1st, 2010 to December 31st, 2015, of which 83% were in AA patients, (n = 10,027). Among AAs, pathology reports confirmed 4070 patients with polyps including 252 with SSPs. Demographic and clinical variables (i.e. sex, age, BMI, anatomic location, clinical symptoms, polyp size, and clinical indications were collected at colonoscopy.

RESULTS

In the AA population, the median age was 56 with interquartile range (IQR) of 51 to 62 years, 54% were female, and 48% had a BMI > 30. The most common reason for colonoscopy was screening (53%), whereas the prevalent reasons for diagnostic colonoscopies were changes in bowel habits (18%) and gastrointestinal bleeding (17%). The total number of SSPs among the 252 AA (diagnosed with SSPs) was 338. Of these, 9% (n = 29/338) had some degree of cytological dysplasia, primarily in the ascending colon (n = 6/42, 14%), Transverse colon (n = 2/16, 13%) and rectosigmoid (n = 19/233, 8%). About 24% of patients had more than 2 polyps. Most patients (76%) had distal SSPs (rectal and rectosigmoid), in comparison to 14% of proximal polyps and 10% of bilateral locations. Median SSA/P size for all locations was 0.6 cm.

CONCLUSION

The prevalence of SSPs accounts for 6% of all polyps in AA patients and was diagnosed in 2.5% of all colonoscopies (n = 252/10,027), which is higher than Caucasians in the US. SSPs were predominantly located in the left side, as compared to published literature showing the predominance in the right side of the colon. Screening of CRC will have the chance to detect high risk SSA/P in this population.

Optimal age for screening colonoscopy: a modeling study

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Confounders in Adenoma Detection at Initial Screening Colonoscopy: A Factor in the Assessment of Racial Disparities as a Risk for Colon Cancer

Background and Aims

The incidence and mortality of colorectal cancer is persistently highest in Black/African-Americans in the United States. While access to care, barriers to screening, and poverty might explain these findings, there is increased interest in examining biological factors that impact the colonic environment. Our group is examining biologic factors that contribute to disparities in development of adenomas prospectively. In preparation for this and to characterize a potential patient population, we conducted a retrospective review of initial screening colonoscopies in a cohort of patients.

Methods

A retrospective review was performed on initial average risk screening colonoscopies on patients (age 45-75 years) during 2012 at three institutions. Descriptive statistics and multivariable logistic regression models were used to examine the relationship between potential risk factors and the detection of adenomas.

Results

Of the 2225 initial screening colonoscopies 1495 (67.2%) were performed on Black/African-Americans and 566 (25.4%) on Caucasians. Multivariable logistic regression revealed that older age, male sex, current smoking and teaching gastroenterologists were associated with higher detection of adenomas and these were less prevalent among Black/African-Americas except for age. Neither race, ethnicity, BMI, diabetes mellitus, HIV nor insurance were associated with adenoma detection.

Conclusion

In this sample, there was no association between race and adenoma detection. While this may be due to a lower prevalence of risk factors for adenomas in this sample, our findings were confounded by a lower detection rate by consultant gastroenterologists at one institution. The study allowed us to rectify the problem and characterize patients for future trials.

Effects of supplemental calcium and vitamin D on tight-junction proteins and mucin-12 expression in the normal rectal mucosa of colorectal adenoma patients

The physical gut barrier, comprised of a thick mucus layer and the epithelium, plays an important role in defense against microbes and foreign antigens. Calcium and vitamin D may be involved in maintaining the integrity of the intestinal mucosal barrier, the dysfunction of which may lead to endotoxemia and inflammation, and contribute to colorectal carcinogenesis. We investigated supplemental calcium (1200 mg, daily) and/or vitamin D₃ (1000 IU daily) effects on intestinal barrier function-related biomarkers in a subset of 105 participants from a large colorectal adenoma recurrence chemoprevention clinical trial. We assessed expression of the tight junction proteins claudin-1 (CLDN1), occludin (OCLD), and mucin-12 (MUC12) in the normal-appearing colorectal mucosa using standardized, automated immunohistochemistry and quantitative image analysis. Following 1 year of treatment, in the calcium relative to the no calcium group, the CLDN1, OCLD, and MUC12 expression increased by 14% (P = 0.17), 23% (P = 0.11), and 22% (P = 0.07), respectively. In secondary analyses, the estimated calcium treatment effects were greater among participants with baseline serum 25-OH-vitamin D concentrations below the median value of 22.69 ng/mL (CLDN1: 29%, P = 0.04; OCLD: 36%, P = 0.06; MUC12: 35%, P = 0.05). There were no biomarker expression changes in the vitamin D₃ alone group; however, modest increases were found in the combined calcium/vitamin D₃ group. At baseline, obesity, history of a sessile-serrated adenoma, colorectal MIB-1/Ki-67 expression, and a family history of colorectal cancer were associated with CLDN1, OCLD, and MUC12 expression. Our study supports continued investigation of factors that could affect intestinal mucosal barrier integrity relevant to colorectal carcinogenesis.

W∗d -test: robust distance-based multivariate analysis of variance

BACKGROUND

Community-wide analyses provide an essential means for evaluation of the effect of interventions or design variables on the composition of the microbiome. Applications of these analyses are omnipresent in microbiome literature, yet some of their statistical properties have not been tested for robustness towards common features of microbiome data. Recently, it has been reported that PERMANOVA can yield wrong results in the presence of heteroscedasticity and unbalanced sample sizes.

FINDINGS

We develop a method for multivariate analysis of variance, [Formula: see text], based on Welch MANOVA that is robust to heteroscedasticity in the data. We do so by extending a previously reported method that does the same for two-level independent factor variables. Our approach can accommodate multi-level factors, stratification, and multiple post hoc testing scenarios. An R language implementation of the method is available at https://github.com/alekseyenko/WdStar .

CONCLUSION

Our method resolves potential for confounding of location and dispersion effects in multivariate analyses by explicitly accounting for the differences in multivariate dispersion in the data tested. The methods based on [Formula: see text] have general applicability in microbiome and other 'omics data analyses.