Race and Prevalence of Large Bowel Polyps Among the Low-Income and Uninsured in South Carolina

Dual ensemble system for polyp segmentation with submodels adaptive selection ensemble

Colonoscopy is one of the main methods to detect colon polyps, and its detection is widely used to prevent and diagnose colon cancer. With the rapid development of computer vision, deep learning-based semantic segmentation methods for colon polyps have been widely researched. However, the accuracy and stability of some methods in colon polyp segmentation tasks show potential for further improvement. In addition, the issue of selecting appropriate sub-models in ensemble learning for the colon polyp segmentation task still needs to be explored. In order to solve the above problems, we first implement the utilization of multi-complementary high-level semantic features through the Multi-Head Control Ensemble. Then, to solve the sub-model selection problem in training, we propose SDBH-PSO Ensemble for sub-model selection and optimization of ensemble weights for different datasets. The experiments were conducted on the public datasets CVC-ClinicDB, Kvasir, CVC-ColonDB, ETIS-LaribPolypDB and PolypGen. The results show that the DET-Former, constructed based on the Multi-Head Control Ensemble and the SDBH-PSO Ensemble, consistently provides improved accuracy across different datasets. Among them, the Multi-Head Control Ensemble demonstrated superior feature fusion capability in the experiments, and the SDBH-PSO Ensemble demonstrated excellent sub-model selection capability. The sub-model selection capabilities of the SDBH-PSO Ensemble will continue to have significant reference value and practical utility as deep learning networks evolve.

Tri-branch feature pyramid network based on federated particle swarm optimization for polyp segmentation

Deep learning technology has shown considerable potential in various domains. However, due to privacy issues associated with medical data, legal and ethical constraints often result in smaller datasets. The limitations of smaller datasets hinder the applicability of deep learning technology in the field of medical image processing. To address this challenge, we proposed the Federated Particle Swarm Optimization algorithm, which is designed to increase the efficiency of decentralized data utilization in federated learning and to protect privacy in model training. To stabilize the federated learning process, we introduced Tri-branch feature pyramid network (TFPNet), a multi-branch structure model. TFPNet mitigates instability during the aggregation model deployment and ensures fast convergence through its multi-branch structure. We conducted experiments on four different public datasets：CVC-ClinicDB, Kvasir, CVC-ColonDB and ETIS-LaribPolypDB. The experimental results show that the Federated Particle Swarm Optimization algorithm outperforms single dataset training and the Federated Averaging algorithm when using independent scattered data, and TFPNet converges faster and achieves superior segmentation accuracy compared to other models.

Causes and Prevention of Early-Onset Colorectal Cancer

Sporadic colorectal cancer (CRC) has historically been considered a disease of the elderly. However, early-onset colorectal cancer (eoCRC) incidence and prevalence have steadily increased over the last few decades, highlighting the critical need for a comprehensive understanding of its causes and prevention. This research examines the numerous factors contributing to the increasing incidence of eoCRC. These factors include a combination of genetic predispositions and environmental effects. We also investigate the impact of modifiable lifestyle factors like obesity, physical inactivity, and an unhealthy diet on eoCRC risk. Understanding these factors is critical in developing future diagnostic, prognostic, disease monitoring, and therapy planning strategies in managing eoCRC and will help optimize guidelines for CRC screening.

Comparison of Concordance of Peptic Ulcer Disease, Non-Adenomatous Intestinal Polyp, and Gallstone Disease in Korean Monozygotic and Dizygotic Twins: A Cross-Sectional Study

Epidemiological studies have suggested the role of multiple genetic and environmental factors in the development of non-neoplastic gastrointestinal (GI) diseases; however, little information is available on these factors in the Korean population. Therefore, this cross-sectional study explored the effect of these factors by analyzing the concordance of several benign GI disorders in 525 monozygotic twins compared to that in 122 dizygotic twins aged >20 years from the Healthy Twin Study data of the Korean Genome and Epidemiology Study (2005-2014). Chi-square test, Wilcoxon rank-sum, and binomial and multinomial logistic regression models were used for statistical analysis. There was lack of concordance of gastric/duodenal ulcers and cholelithiasis/cholangitis between monozygotic twins compared to that in dizygotic twins, suggesting that environmental factors may mediate those concordant disease expressions in monozygotic twins. The concordance of intestinal polyps in monozygotic twins was 32% lower than that in dizygotic twins (p = 0.028), indicating that the effect of genetic factors on the risk for intestinal polyp development may be low. In conclusion, the lack or low concordance of several benign GI diseases between monozygotic and dizygotic twin groups suggests the relative importance of environmental factors, indicating that these are preventable diseases.

Age-Stratified Prevalence and Predictors of Neoplasia Among U.S. Adults Undergoing Screening Colonoscopy in a National Endoscopy Registry

BACKGROUND & AIMS

Several U.S. organizations now recommend starting average-risk colorectal cancer screening at age 45 years, but the prevalence of colonic neoplasia in individuals younger than 50 years has not been well characterized. We used a national endoscopic registry to calculate age-stratified prevalence and predictors of colorectal neoplasia.

METHODS

Outpatient screening colonoscopies performed during 2010-2020 in the GI Quality Improvement Consortium registry were analyzed. We measured the prevalence of advanced neoplasia and adenomas by age, sex, and race/ethnicity, as well as the prevalence ratio of neoplasia compared with the reference group of 50- to 54-year-olds. Multivariable logistic regression models were used to identify predictors of neoplasia.

RESULTS

We identified 3,928,727 screening colonoscopies, of which 129,736 (3.3%) were performed on average-risk individuals younger than 50 years. The prevalence of advanced neoplasia was 6.2% for 50- to 54-year-olds and 5.0% (prevalence ratio, 0.81; 95% confidence interval, 0.78-0.83) for average-risk 45- to 49-year-olds. Men had higher prevalence of neoplasia than women for all age groups. White individuals had higher prevalence of advanced neoplasia than persons of other racial/ethnic groups in most age groups, which was partially driven by serrated lesions. On multivariable regression, White individuals had higher odds of advanced neoplasia than Black, Hispanic, and Asian individuals in both younger and older age groups.

CONCLUSIONS

In a large U.S. endoscopy registry, the prevalence of advanced neoplasia in 45- to 49-year-olds was substantial and supports beginning screening at age 45 years. White individuals had higher risk of advanced neoplasia than Black, Hispanic, and Asian individuals across the age spectrum. These findings may inform adenoma detection benchmarks and risk-based screening strategies.

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.

Characteristics of Serrated Adenomas in Non-Hispanic Whites and African Americans Undergoing Screening Colonoscopy

Background and aim

Adenomatous polyps are precursor lesions for colorectal cancer (CRC). Serrated adenomas/polyps are considered a risk factor for the development of proximal and interval CRC. African-Americans are at higher risk for right-sided CRC. Minimal data evaluating serrated adenoma characteristics by race/ethnicity on initial screening colonoscopy (SC) exist. The aim of this investigation was to compare the characteristics of serrated adenomas found in non-Hispanic whites (nHw) and African-Americans (AA) undergoing initial SC.

Methods

The University of Florida-Jacksonville endoscopy database was searched for all SC performed between January 2000 and December 2014. Inclusion criteria were nHw or AA race/ethnicity and histologically proven serrated adenoma found at SC. Data were collected for all included age at SC, sex, number, location, and size of serrated adenomas found.

Results

A total of 8693 individuals (nHw - 4199 and AA - 4494) underwent SC between January 2000 and December 2014. Serrated adenomas were found in 479 individuals (nHw, n=294; AA, n=185), and AA were significantly less likely than nHw to have serrated adenomas on SC (AA 4.1% vs nHw 7%; p< 0.0001). No difference was observed in mean age, location, or size between nHw and AA with serrated adenomas.

Conclusions

Serrated adenomas are more frequent in nHw compared to AA at initial SC. No difference was seen in size or location of serrated adenomas, as well as patient age, between AA and nHw. A study of genetic factors predisposing to serrated adenoma formation and the impact of socioeconomic disparities should be performed across ethnic groups to understand this difference.

Preinvasive Colorectal Lesions of African Americans Display an Immunosuppressive Signature Compared to Caucasian Americans

Background

African Americans (AAs) have higher colorectal cancer (CRC) incidence and mortality rate than Caucasian Americans (CAs). Recent studies suggest that immune responses within CRCs contribute to the disparities. If racially distinct immune signatures are present in the early phases of carcinogenesis, they could be used to develop interventions to prevent or slow disease.

Methods

We selected a convenience sample of 95 patients (48 CAs, 47 AAs) with preinvasive colorectal adenomas from the surgical pathology laboratory at the Medical University of South Carolina. Using immunofluorescent-conjugated antibodies on tissue slides from the lesions, we quantified specific immune cell populations: mast cells (CD117⁺), Th17 cells (CD4⁺RORC⁺), and NK cell ligand (MICA/B) and inflammatory cytokines, including IL-6, IL-17A, and IFN-γ. We compared the mean density counts (MDCs) and density rate ratios (RR) and 95% CI of immune markers between AAs to CAs using negative binomial regression analysis. We adjusted our models for age, sex, clinicopathologic characteristics (histology, location, dysplasia), and batch.

Results

We observed no racial differences in age or sex at the baseline endoscopic exam. AAs compared to CAs had a higher prevalence of proximal adenomas (66% vs. 40%) and a lower prevalence of rectal adenomas (11% vs. 23%) (p =0.04) but no other differences in pathologic characteristics. In age, sex, and batch adjusted models, AAs vs. CAs had lower RRs for cells labeled with IFNγ (RR 0.50 (95% CI 0.32-0.81); p=0.004) and NK cell ligand (RR 0.67 (0.43-1.04); p=0.07). In models adjusted for age, sex, and clinicopathologic variables, AAs had reduced RRs relative to CAs for CD4 (p=0.02), NK cell ligands (p=0.01), Th17 (p=0.005), mast cells (p=0.04) and IFN-γ (p< 0.0001).

Conclusions

Overall, the lower RRs in AAs vs. CAs suggests reduced effector response capacity and an immunosuppressive (‘cold’) tumor environment. Our results also highlight the importance of colonic location of adenoma in influencing these differences; the reduced immune responses in AAs relative to CAs may indicate impaired immune surveillance in early carcinogenesis. Future studies are needed to understand the role of risk factors (such as obesity) in influencing differences in immune responses by race.

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.

Prevalence and Clinical Features of Sessile Serrated Polyps: A Systematic Review

BACKGROUND & AIMS

Sessile serrated polyps (SSPs) could account for a substantial proportion of colorectal cancers. We aimed to increase clarity on SSP prevalence and clinical features.

METHODS

We performed a systematic review of MEDLINE, Web of Science, Embase, and Cochrane databases for original studies published in English since 2000. We included studies of different populations (United States general or similar), interventions (colonoscopy, autopsy), comparisons (world regions, alternative polyp definitions, adenoma), outcomes (prevalence, clinical features), and study designs (cross-sectional). Random-effects regression was used for meta-analysis where possible.

RESULTS

We identified 74 relevant colonoscopy studies. SSP prevalence varied by world region, from 2.6% in Asia (95% confidence interval [CI], 0-5.9) to 10.5% in Australia (95% CI, 2.8-18.2). Prevalence values did not differ significantly between the United States and Europe (P = .51); the pooled prevalence was 4.6% (95% CI, 3.4-5.8), and SSPs accounted for 9.4% of polyps with malignant potential (95% CI, 6.6-12.3). The mean prevalence was higher when assessed through high-performance examinations (9.1%; 95% CI, 4.0-14.2; P = .04) and with an alternative definition of clinically relevant serrated polyps (12.3%; 95% CI, 9.3-15.4; P < .001). Increases in prevalence with age were not statistically significant, and prevalence did not differ significantly by sex. Compared with adenomas, a higher proportion of SSPs were solitary (69.0%; 95% CI, 45.9-92.1; P = .08), with diameters of 10 mm or more (19.3%; 95% CI, 12.4-26.2; P = .13) and were proximal (71.5%; 95% CI, 63.5-79.5; P = .008). The mean ages for detection of SSP without dysplasia, with any or low-grade dysplasia, and with high-grade dysplasia were 60.8 years, 65.6 years, and 70.2 years, respectively. The range for proportions of SSPs with dysplasia was 3.7%-42.9% across studies, possibly reflecting different study populations.

CONCLUSIONS

In a systematic review, we found that SSPs are relatively uncommon compared with adenoma. More research is needed on appropriate diagnostic criteria, variations in detection, and long-term risk.

Terminology, Molecular Features, Epidemiology, and Management of Serrated Colorectal Neoplasia

In addition to the adenoma to carcinoma sequence, colorectal carcinogenesis can occur via the serrated pathway. Studies have focused on clarification of categories and molecular features of serrated polyps, as well as endoscopic detection and risk assessment. Guidelines from the World Health Organization propose assigning serrated polyps to categories of hyperplastic polyps, traditional serrated adenomas, and sessile serrated lesions (SSLs). Traditional serrated adenomas and SSLs are precursors to colorectal cancer. The serrated pathway is characterized by mutations in RAS and RAF, disruptions to the Wnt signaling pathway, and widespread methylation of CpG islands. Epidemiology studies of serrated polyps have been hampered by inconsistencies in terminology and reporting, but the prevalence of serrated class polyps is 20%-40% in average-risk individuals; most serrated polyps detected are hyperplastic. SSLs, the most common premalignant serrated subtype, and are found in up to 15% of average-risk patients by high-detecting endoscopists. Variations in rate of endoscopic detection of serrated polyps indicate the need for careful examination, with adequate bowel preparation and sufficient withdrawal times. Risk factors for SSLs include white race, family history of colorectal cancer, smoking, and alcohol intake. Patients with serrated polyps, particularly SSLs and traditional serrated adenomas, have an increased risk of synchronous and metachronous advanced neoplasia. Surveillance guidelines vary among countries, but SSLs and proximal hyperplastic polyps require special attention in assignment of surveillance interval-especially in light of concerns regarding incomplete detection and resection.

Formative Research on Knowledge and Preferences for Stool-based Tests compared to Colonoscopy: What Patients and Providers Think

The rates of colorectal cancer (CRC) screening in the U.S. remain below national targets, so many people at risk are not being screened. The objective of this qualitative research project was to assess patient and provider knowledge and preferences about CRC screening modalities and specifically the use of the fecal immunochemical test (FIT) as a first line screening choice. Nine focus groups were conducted with a medically underserved patient population and qualitative interviews were administered to their medical providers. Thematic analysis was used to synthesize key findings. Both providers and patients thought that the FIT would be a good option for CRC screening both as an individual choice and for an overall program approach. The test is less expensive and therefore more readily available for patients compared to colonoscopy. Overall, there was consensus that the FIT offers a reasonably priced, simple approach to CRC screening which has broad appeal to both providers and patients. Concerns identified by patients and providers included the possibility of false positives with the FIT which could be caused by test contamination or failing to perform the test properly. Patients also described feelings of disgust toward performing the FIT and difficulties in following the instructions. Study findings indicate provider and patient support for using the FIT for CRC screening at both the individual and system-wide levels of implementation. While barriers to the use of the FIT were listed, benefits of using the FIT were perceived as positive motivators to engage previously unscreened and uninsured or under-insured individuals in CRC screening.

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.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Helicobacter pylori is associated with increased risk of serrated colonic polyps: Analysis of serrated polyp risk factors

BACKGROUND

Sessile serrated adenomas (SSA) and traditional serrated adenomas (TSA) are recognized precursors of colorectal cancer, but their risk factors are not well established. We investigated the association between Helicobacter pylori infection (HPI) and the development of SSA and TSA.

METHODS

Retrospective data were collected on patients aged ≥ 18 years that underwent colonoscopy with biopsy between 2006 and 2016. Based on histology, patients were classified into three groups: those with SSA and/or TSA, (serrated neoplasia group, SN); conventional adenomas only (CA); and with no polyps (NP). Gastric HPI status, demographic, and clinical risk factors were compared between groups using bivariate and multivariable analysis.

RESULTS

HPI was significantly associated with increased risk of SN (SN vs. NP: OR 1.71 [95% CI 1.29-2.27]; SN vs. CA: 1.49 [1.14-1.96]). Additional factors associated with increased risk of SN included the following: age 50-75 years, compared to younger age (SN vs. NP: 2.83 [1.69-4.74]), female gender (SN vs. CA: 1.28 [0.99-1.64]), White race, compared to Blacks (SN vs. CA: 1.52 [1.07-2.15)], overweight and obese body mass index [SN vs. NP: p < 0.001) and current smoking status (SN vs. CA: 2.09 [1.55-2.82)]. Among SN, higher HPI prevalence was associated with dysplasia (p = 0.05) and proximal location (p = 0.01).

CONCLUSIONS

Our data suggest that gastric HPI is associated with increased risk of SN and CA, with a stronger association with SN as compared to CA. Age 50-75 years, female gender, White race, obesity, and smoking were also predictors of SN. A positive correlation of HPI with proximal and dysplastic SN suggests a possible role in serrated pathway carcinogenesis. Prospective studies with large patient population are needed to further investigate this association.

Diagnosis and predictors of sessile serrated adenoma after educational training in a large, community-based, integrated healthcare setting

BACKGROUND AND AIMS

Sessile serrated adenomas (SSAs) are precursors of 15% to 30% of colorectal cancers but are frequently underdiagnosed. We sought to measure the SSA detection rate (SDR) and predictors of SSA detection after educational training for community gastroenterologists and pathologists.

METHODS

Colonoscopy and pathology data (2010-2014) from 3 medical centers at Kaiser Permanente Northern California were accessed electronically. Gastroenterologists and pathologists attended a training session on SSA diagnosis in 2012. Mean SDRs and patient-level predictors of SSA detection post-training (2013-2014) were investigated.

RESULTS

Mean SDRs increased from .6% in 2010-2012 to 3.7% in 2013-2014. The increase in the detection of proximal SSAs was accompanied by a decrease in the detection of proximal hyperplastic polyps (HPs). Among 34,161 colonoscopies performed in 2013 to 2014, SDRs for screening, fecal immunochemical test positivity, surveillance, and diagnostic indication were 4.2%, 4.5%, 4.9%, and 3.0%, respectively. SSA detection was lower among Asians (adjusted odds ratio [aOR], .46; 95% confidence interval [CI], .31-.69) and Hispanics (aOR, .59; 95% CI, .36-.95) compared with non-Hispanic whites and higher among patients with synchronous conventional adenoma (aOR, 1.46; 95% CI, 1.15-1.86), HP (aOR, 1.74; 95% CI, 1.30-2.34), and current smokers (aOR, 1.78; 95% CI, 1.17-2.72). SDRs varied widely among experienced gastroenterologists, even after training (1.1%-8.1%). There was a moderately strong correlation between adenoma detection rate (ADR) and SDR for any SSA (r = .64, P = .0003) and for right-sided SSAs (r = .71, P < .0001).

CONCLUSIONS

Educational training significantly increased the detection of SSA, but a wide variation in SDR remained across gastroenterologists. SSA detection was inversely associated with Asian and Hispanic race/ethnicity and positively associated with the presence of conventional adenoma, HP, and current smoking. There was a moderately strong correlation between ADR and SDR.

Herniation of crypts in hyperplastic polyp and sessile serrated adenoma: a prospective study

Presence of colonic crypts in submucosa was previously termed as herniation of crypts, pseudoinvasion, epithelial-misplacement, or inverted hyperplastic-polyp. It is considered as an important criterion for diagnosing sessile serrated adenoma (SSA), which links to a higher risk of synchronous and future colorectal cancers compared with hyperplastic polyp (HP). Here, we aimed to study the frequencies, diagnostic specificity and synchronous neoplasms of herniation of crypts in HP and SSA. We prospectively included all HP and SSA cases and 514 randomly-selected colorectal polyps of normal histology diagnosed from 2013 to 2015 at our institution. We calculated the frequencies of herniation of crypts by histology, sex, age, size, race, location, prior polyp-history and synchronous neoplasms (including colorectal cancers and adenomas). Binary and ordinal (ordered) logistic regression analyses were used to identify potential associations. Among the 2,560 colorectal polyps in the subjects with average-risk of colorectal cancer, the frequencies of herniation of crypts were 1.79% (10/559) in SSA, 0.2% (3/1487) in HP and 0% (0/514) in polypoid normal tissue. The specificity of herniation of crypts for diagnosing serrated polyp (HP and SSA versus normal tissue) was 100% (514/514), but its sensitivity was 0.64% (13/2046), while the specificity of herniation of crypts for diagnosing SSA (versus HP and polypoid normal tissue) was 99.85% (1998/2001) and its sensitivity was 1.79% (10/559). Our multivariate analyses identified an independent association between herniation of crypts and diagnosis of SSA (Odds ratio [OR]=9.37, P=0.015 for versus HP and normal tissue, and OR=11.47, P=0.009 for versus HP). We also found that herniation of crypts in SSA and HP did not independently link to race or synchronous neoplasms (including cancers and adenomas). In summary, our data show that, while herniation of crypts is rare, its presence is highly suggestive of SSA.

Proximal Sessile Serrated Adenomas Are More Prevalent in Caucasians, and Gastroenterologists Are Better Than Nongastroenterologists at Their Detection

Background and Aim

Proximal sessile serrated adenomas (PSSA) leading to colorectal cancer (CRC) represent an alternate pathway for CRC development. In this study, we aim to determine the prevalence of PSSAs and the impact of patient, colonoscopy, and endoscopist-related factors on PSSA detection.

Methods

Patients ≥ 50 years of age undergoing a screening colonoscopy between 2012 and 2014 were included. Detection rates based on patient gender, race, colonoscopy timing, fellow participation, bowel preparation quality, and specialty of the endoscopist were calculated. t-tests were used to compare detection rates and a multivariate-adjusted analysis was performed.

Results

140 PSSAs were detected from 4151 colonoscopies, with a prevalence of 3.4%. Detection rate was higher in Caucasians compared to African-Americans (AA) (3.7 ± 4.1 versus 0.96 ± 3.5; p < 0.001). Gastroenterologists detected more PSSAs compared to nongastroenterologists (3.9 ± 3.5 versus 2.2 ± 3.0; p = 0.028). These findings were still significant after adjusted multivariate analysis. The rest of the factors did not make significant difference in PSSA detection rate.

Conclusions

PSSAs are more prevalent in Caucasians compared to AAs. Racial difference in prevalence of PSSAs is intriguing and warrants further investigation. Gastroenterologists have a significantly higher PSSADR compared to nongastroenterologists. Educational measures should be implemented in nongastroenterologists to improve their PSSA detection rates.

The Serrated Polyp Pathway: Is It Time to Alter Surveillance Guidelines?

PURPOSE OF REVIEW

In this manuscript, we review current surveillance guidelines for serrated polyps (SPs) and discuss how recent studies inform the selection of appropriate surveillance intervals for patients with SPs.

RECENT FINDINGS

Large and/or proximal SPs, particularly sessile serrated polyps (SSPs), are associated with increased risk of both synchronous and metachronous neoplasia, including advanced adenomas and colorectal cancer (CRC). Persons harboring multiple SSPs or dysplastic SSPs are at the highest risk. Moreover, a high percentage of large and/or proximal SPs are reclassified as SSPs when read by trained gastrointestinal pathologists, even if they were originally reported as hyperplastic polyps. These findings support the adoption of surveillance guidelines that prescribe closer surveillance of large and/or proximal SPs, regardless of subtype. SSPs remain a challenge to reliably identify, resect, and diagnose via histology. The increased risk of future neoplasia in patients with SSPs is likely driven by a combination of underdetection, inadequate removal, misclassification, and biology. Until further evidence emerges, we support guidelines that recommend close surveillance of patients with a history of large and/or proximal SPs and SSPs specifically in order to mitigate the threat of interval CRC.

Colorectal Cancer in Young African Americans: Is It Time to Revisit Guidelines and Prevention?

BACKGROUND & AIMS

Previous studies have suggested an increase in the incidence of colorectal cancer (CRC) in young adults (younger than 50 years). Among older people, African Americans have disproportionally higher CRC incidence and mortality. We assessed whether this CRC disparity also applies to CRC diagnosed among young people.

METHODS

Using the Surveillance, Epidemiology, and End Results cancer registries, a population-based cancer registry covering 25.6 % of the United States' African American population, we identified patients diagnosed with CRC between the years of 2000-2012. The age-adjusted rates for non-Hispanic whites (NHW), African Americans, and Asian-Pacific Islanders (API) were calculated for the age categories 20-24, 25-29, 30-34, 35-39, and 40-44.

RESULTS

CRC age-adjusted incidence is increasing among all three racial groups and was higher for African Americans compared to NHW and API across all years 2000-2012 (P < 0.001). Stage IV CRC was higher in African Americans compared with NHW, while there was higher stage III CRC in API compared with NHWs.

CONCLUSION

CRC incidence is increasing among the young in all racial groups under study. This increase in frequency of CRC is true among young African American adults who display highly advanced tumors in comparison with other races. While the present attention to screening seems to have decreased CRC prevalence in individuals older than 50, special attention needs to be addressed to young African American adults as well, to counter the observed trend, as they have the highest incidence of CRC among young population groups by race/ethnicity.