The association of lifestyle and dietary factors with the risk for serrated polyps of the colorectum

The histologic features, molecular features, detection and management of serrated polyps: a review

The serrated pathway to colorectal cancers (CRCs) is a significant pathway encompassing five distinct types of lesions, namely hyperplastic polyps (HPs), sessile serrated lesions (SSLs), sessile serrated lesions with dysplasia (SSL-Ds), traditional serrated adenomas (TSAs), and serrated adenoma unclassified. In contrast to the conventional adenoma-carcinoma pathway, the serrated pathway primarily involves two mechanisms: BRAF/KRAS mutations and CpG island methylator phenotype (CIMP). HPs are the most prevalent non-malignant lesions, while SSLs play a crucial role as precursors to CRCs, On the other hand, traditional serrated adenomas (TSAs) are the least frequently encountered subtype, also serving as precursors to CRCs. It is crucial to differentiate these lesions based on their unique morphological characteristics observed in histology and colonoscopy, as the identification and management of these serrated lesions significantly impact colorectal cancer screening programs. The management of these lesions necessitates the crucial steps of removing premalignant lesions and implementing regular surveillance. This article provides a comprehensive summary of the epidemiology, histologic features, molecular features, and detection methods for various serrated polyps, along with recommendations for their management and surveillance.

Lansoprazole inhibits the development of sessile serrated lesions by inducing G1 arrest via Skp2/p27 signaling pathway

BACKGROUND

Although the serrated-neoplasia pathway reportedly accounts for 15-30% of colorectal cancer (CRC), no studies on chemoprevention of sessile serrated lesions (SSLs) have been reported. We searched for effective compounds comprehensively from a large series of compounds by employing Connectivity Map (CMAP) analysis of SSL-specific gene expression profiles coupled with in vitro screening using SSL patient-derived organoids (PDOs), and validated their efficacy using a xenograft mouse model of SSL.

METHODS

We generated SSL-specific gene signatures based on DNA microarray data, and applied them to CMAP analysis with 1309 FDA-approved compounds to select candidate compounds. We evaluated their inhibitory effects on SSL-PDOs using a cell viability assay. SSL-PDOs were orthotopically transplanted into NOG mice for in vivo evaluation. The signal transduction pathway was evaluated by gene expression profile and protein expression analysis.

RESULTS

We identified 221 compounds by employing CMAP analysis of SSL-specific signatures, which should cancel the gene signatures, and narrowed them down to 17 compounds. Cell viability assay using SSL-PDOs identified lansoprazole as having the lowest IC50 value (47 µM) among 17 compounds. When SSL-PDO was orthotopically transplanted into murine intestinal tract, the tumor grew gradually. Administration of lansoprazole to mice inhibited the growth of SSL xenograft whereas the tumor in control mice treated with vehicle alone grew gradually over time. The Ki67 index in xenograft lesions from the lansoprazole group was significantly lower compared with the control group. Cell cycle analysis of SSL-PDOs treated with lansoprazole exhibited a significant increase in G1 phase cell population. Microarray and protein analysis revealed that lansoprazole downregulated Skp2 expression and upregulated p27 expression in SSL-PDOs.

CONCLUSIONS

Our data strongly suggest that lansoprazole is the most effective chemopreventive agent against SSL, and that lansoprazole induces G1 cell cycle arrest by downregulating Skp2 and upregulating p27 in SSL cells.

Metabolic risk factors link unhealthy lifestyles to the risk of colorectal polyps in China

Colorectal cancer is the second leading cause of global cancer-related deaths, and its precursor lesions are colorectal polyps (CAP). The study aimed to explore the effect of combinations of unhealthy lifestyles on CAP and investigate the mediation role of metabolic disorder in this process. A total of 1299 adults were recruited from a hospital in Jiangsu, China, including 811 cases and 488 adults without diseases. The information on demographic characteristics and lifestyles was collected through questionnaires and the medical record system. Serum biochemical parameters were determined using the automatic biochemical analyzer. Adjusted regression analysis showed that unhealthy lifestyles, including smoking, overnight meals, daily water intake, staying up late, and exercise associated with the risk of CAP. Furthermore, metabolic biomarkers, including BMI, triglycerides, and uric acid, were associated with the risk of CAP. Also, unhealthy lifestyle scores were positively associated with BMI, triglycerides, and CAP. The mediation effect of metabolic biomarkers, such as BMI and triglycerides on the association of unhealthy lifestyle scores with CAP was significant. Available data demonstrate the adverse effect of combinations of unhealthy lifestyle factors on CAP, and metabolic disorders to potentially mediate the association of unhealthy lifestyles with the risk of CAP.

Risk factors for sessile serrated lesions among Chinese patients undergoing colonoscopy

BACKGROUND AND AIM

Serrated polyps have been recognized as a premalignant lesion accounting for a significant proportion of colorectal cancer. Limited data are available regarding the risk factors for colorectal sessile serrated lesions (SSLs). We aimed to investigate clinical risk factors of SSLs and compared them with colorectal adenomas in a study population of Chinese individuals.

METHODS

A retrospective case-control study was performed in an academic tertiary-referral center in Hong Kong. Subjects with SSLs and adenomas were identified from the hospital pathology database from January 2010 to December 2020, and additional clinical data were retrieved from the electronic patient record system. We compared clinical features and risk factors of SSL patients with those without these lesions.

RESULTS

A total of 2295 subjects were included in the study, including 459 subjects with SSLs, 918 subjects with adenomas, and 918 subjects with normal colonoscopy. By multivariable logistic regression, compared with normal subjects, patients with SSLs only were significantly more likely to have dyslipidemia (adjusted OR: 1.431, 95% CI 1.008-2.030) and diabetes mellitus (adjusted OR: 2.119, 95% CI 1.439-3.122).

CONCLUSIONS

Dyslipidemia and diabetes were independent risk factors for SSLs. Our findings suggest these metabolic factors may be important for the risk of SSLs. The findings may improve our understanding of SSLs and shed light on patient selection for screening and risk stratification.

Characteristics and risk factors for colorectal polyps among children in an urban area of Wenzhou, China: a retrospective case control study

BACKGROUND

Scarce evidence exists on pediatric colorectal polyp risk factors. This study explored the clinical manifestations, morphological and pathological characteristics of, and risk factors for pediatric colorectal polyps.

METHODS

This retrospective case-control study included children who received colonoscopy, divided into a colorectal polyp group and a normal control group based on colonoscopy results. The risk factors for colorectal polyps in children were analyzed through logistic regression analysis.

RESULTS

The mean age of children with polyps was 6.77 ± 3.44 years. Polyps were detected predominantly in males (72.9%); hematochezia was the primary clinical manifestation (80.25%). Most polyps were juvenile (88.9%) and solitary (87.7%); 50.6% were located in the rectosigmoid area. Univariate analysis showed that gender (P = 0.037), age (P < 0.001), family aggregation (P < 0.001), specific immunoglobulin E (sIgE) (P < 0.001), platelet count (P = 0.001), aspartate aminotransferase (AST) (P = 0.016), meat intake (P = 0.010), and vegetable intake (P < 0.001) were significantly associated with colorectal polyps. Age ≤ 6 years (3-6 years: OR: 26.601, 95% CI: 3.761-160.910; < 3 years: OR: 22.678, 95% CI: 1.873-274.535), positive family aggregation (OR: 3.540, 95% CI: 1.177-10.643), positive sIgE (OR:2.263, 95% CI: 1.076-4.761), and higher meat intake (OR:1.046, 95% CI: 1.029-1.063) were risk factors for pediatric colorectal polyps in logistic regression analysis. Higher vegetable intake (OR: 0.993, 95% CI: 0.986-1.000) was a protective factor against pediatric colorectal polyps. The area under the curve (AUC) of meat intake in the receiver operating characteristic (ROC) curve analysis for predicting colorectal polyps was 0.607; the best cut-off value was 92.14 g/d (P = 0.010, 95% CI: 0.527-0.687). The meat and vegetable intake combination AUC in predicting pediatric colorectal polyps was 0.781 (P < 0.001, 95% CI: 0.718-0.845).

CONCLUSIONS

Juvenile, solitary, and located in the rectosigmoid region polyps are most common in children. Hematochezia is the main clinical manifestation. Most polyps were, but multiple and proximally located polyps were also detected. Age ≤ 6 years, especially 3-6 years, positive family aggregation, positive sIgE, and higher meat intake are risk factors for pediatric colorectal polyps. A higher vegetable intake is a protective factor.

Correlations of high molecular weight adiponectin, tumor necrosis factor-alpha and vascular endothelial growth factors with occurrence of colonic polyps in the prediabetic population

We aimed to explore the correlations of high molecular weight adiponectin (HMW-ADP), tumor necrosis factor-alpha (TNF-α) and vascular endothelial growth factors (VEGFs) with the occurrence of colonic polyps in the prediabetic population. Two hundred patients with prediabetes were enrolled, and their clinical data were retrospectively analyzed. They were divided into group A (75 patients with colonic polyps) and group B (125 patients without colonic polyps). Eighty patients with normal glucose tolerance in the same period were divided into group C (32 patients with normal glucose tolerance and colonic polyps) and group D (48 patients with normal glucose tolerance but no colonic polyps). The correlations of serum HMW-ADP, TNF-α and VEGF levels with plasma glucose and insulin levels were explored by Pearson's analysis. The factors influencing the occurrence of colonic polyps were determined by logistic regression analysis. Serum HMW-ADP was negatively correlated with TNF-α, VEGFs, FPG, 2hPG, FI and HOMA-IR (r<0, P<0.05), whereas serum TNF-α and VEGFs were positively correlated with FPG, 2hPG, FI and HOMA-IR (r>0, P<0.05). Age, body mass index, waist-to-hip ratio, history of smoking, history of drinking, family history of colon cancer, TNF-α and VEGF were independent risk factors [odds ratio (OR)>1, P<0.05], and HMW-ADP was a protective factor (OR<1, P<0.05). The areas under the curves of serum HMW-ADP, TNF-α, VEGFs and their combination for predicting the occurrence of colonic polyps were 0.899, 0.787, 0.908 and 0.922, respectively. The combination of HMW-ADP, TNF-α and VEGFs can effectively predict the occurrence of colonic polyps in prediabetic patients.

Association between dietary factors and colorectal serrated polyps: a systematic review and meta-analysis

Background

Dietary factors may affect the incidence of colorectal serrated polyps (SP). However, its effects on SP are unclear as epidemiological studies on this topic have showed inconsistent results. The present systematic review and meta-analysis sought to evaluate the effects of dietary factors on SPs.

Methods

Studies regarding the association between dietary factors and SPs were identified by searching PubMed, Cochrane library, Embase and Chinese Biomedical Literature database from inception until 27 February 2023. Search terms include serrated, hyperplastic, adenoma, polyps, colorectal, rectal, rectum and risk. Heterogeneity was assessed using I2 statistics. The meta-analysis was conducted by using a random-effects model, and the pooled effects were expressed with odds ratios (OR) and 95% confidence intervals (95% CI). Probable sources of heterogeneity were identified through meta-regression. Subgroup analysis were based on lesion types, study designs, countries, and so on.

Results

28 studies were ultimately eligible after scanning, and five dietary factors including vitamin D, calcium, folate, fiber and red or processed meat were excerpted. Higher intakes of vitamin D (OR = 0.95, 95%CI:0.90-1.02), calcium (OR = 0.97, 95%CI: 0.91-1.03) and folate (OR = 0.82, 95% CI: 0.6-1.13) were not significantly associated with SP. Fiber intake (OR = 0.90, 95% CI: 0.82-0.99) was a protective factor against SPs. Red meat intake increased the risk of SPs by 30% for the highest versus lowest intakes (OR = 1.30, 95% CI: 1.13-1.51). For different lesion types, higher folate intake was associated with a decreased risk of HPs (OR = 0.59, 95%CI: 0.44-0.79), and higher vitamin D intake decreased the risk of SPs including SSA/P (OR = 0.93, 95%CI: 0.88-0.98).

Conclusions

Higher dietary fiber intake plays an effective role in preventing SP, while red meat intake is associated with an increased risk of SP. This evidence provides guidance for us to prevent SP from a dietary perspective.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?, RecordID=340750.

Genetic Predisposition to Colorectal Cancer: How Many and Which Genes to Test?

Colorectal cancer is one of the most common tumors, and genetic predisposition is one of the key risk factors in the development of this malignancy. Lynch syndrome and familial adenomatous polyposis are the best-known genetic diseases associated with hereditary colorectal cancer. However, some other genetic disorders confer an increased risk of colorectal cancer, such as Li-Fraumeni syndrome (TP53 gene), MUTYH-associated polyposis (MUTYH gene), Peutz-Jeghers syndrome (STK11 gene), Cowden syndrome (PTEN gene), and juvenile polyposis syndrome (BMPR1A and SMAD4 genes). Moreover, the recent advances in molecular techniques, in particular Next-Generation Sequencing, have led to the identification of many new genes involved in the predisposition to colorectal cancers, such as RPS20, POLE, POLD1, AXIN2, NTHL1, MSH3, RNF43 and GREM1. In this review, we summarized the past and more recent findings in the field of cancer predisposition genes, with insights into the role of the encoded proteins and into the associated genetic disorders. Furthermore, we discussed the possible clinical utility of genetic testing in terms of prevention protocols and therapeutic approaches.

Body Mass Index, sex, non-steroidal anti-inflammatory drug medications, smoking and alcohol are differentially associated with World Health Organisation criteria and colorectal cancer risk in people with Serrated Polyposis Syndrome: an Australian case-control study

OBJECTIVE

The unknown aetiology of Serrated Polyposis Syndrome (SPS) impedes risk prediction and prevention. We investigated risk factors for SPS, overall and stratified by World Health Organization (WHO)²⁰¹⁰ clinical criteria and by colorectal cancer (CRC).

METHOD

A retrospective case-control study involving a cross-sectional analysis from 350 unrelated individuals with SPS from the Genetics of Colonic Polyposis Study and 714 controls from the Australasian Colorectal Cancer Family Registry. Univariate and multivariate logistic regression modelling was used to determine the association between risk factors and SPS and risk factors associated with CRC in SPS.

RESULTS

Female biological sex (odds ratio (OR) = 4.54; 95%Confidence interval (CI) = 2.77-7.45), increasing body mass index (BMI) at age 20 years (OR = 1.09; 95%CI = 1.04-1.13), hormone replacement therapy (OR = 0.44; 95%CI = 0.20.98), and increasing weekly folate intake (OR = 0.82; 95%CI = 0.75-0.90) were associated with SPS by multivariate analysis. Increasing weekly calcium intake (OR = 0.79; 95%CI = 0.64-0.97) and smoking > 10 cigarettes daily (OR = 0.45; 95%CI = 0.23-0.86) were associated with WHO criterion I only. The consumption of 1-100 g of alcohol per week (OR = 0.39; 95%CI = 0.18-0.83) was associated with WHO criterion III only. Smoking 1-5 cigarettes daily (OR = 2.35; 95%CI = 1.09-5.05), weekly non-steroidal anti-inflammatory drug (NSAIDs) intake (OR = 0.88; 95%CI = 0.78-0.99), and increased height (OR = 1.09; 95% = 1.05-1.13), were associated with SPS fulfilling both WHO criteria I and III. Moreover, weekly NSAIDs intake (OR = 0.81; 95%CI = 0.67-0.98) was associated with a reduced likelihood of CRC in SPS.

CONCLUSION

We identified novel risk and potential protective factors associated with SPS, some specific for certain WHO²⁰¹⁰ criteria. Weekly use of NSAIDs may reduce the risk of CRC in people with SPS.

The relationship between serum lipid levels and colorectal serrated lesions: A systematic review and meta-analysis

Objective: To clarify the relationship between colorectal serrated lesions and serum lipid levels, and provide a scientific basis for the identification and early clinical prevention and treatment of populations that are at risk for colorectal serrated lesions.

Methods: Studies comparing serum lipid levels in patients with colorectal serrated lesions and controls were searched in PubMed, Embase, Web of Science, the Cochrane Library, China Biomedical Literature Database, CNKI, Wanfang Database, and VIP Database. Relevant literature was screened according to the inclusion and exclusion criteria. The mean and standard deviation of the serum lipid levels in patients and controls were extracted from the included literature. The combined weighted mean difference (WMD) and 95% confidence intervals (CIs) were calculated using Review Manager 5.0 software to evaluate the relationship between serum lipid levels and colorectal serrated lesions. Publication bias of the included studies was evaluated by the Egger test.

Results: Twenty-three studies were included, comprising 2,063 patients and 63,909 controls. The serum high-density lipoprotein cholesterol (HDL-C) levels in the case group was significantly lower than in the control group (WMD = −0.122 mmol/L, 95% CI: 0.170–0.073). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and serum triglyceride levels in the case group were significantly higher than in the control group, and the WMDs were 0.180 mmol/L (95% CI: 0.061–0.299), 0.155 mmol/L (95% CI: 0.038–0.273), and 0.241 mmol/L (95% CI: 0.181–0.302), respectively.

Conclusion: Colorectal serrated lesions may be related to blood lipid levels. Hyperlipidemia might be a risk factor for colorectal serrated lesions.

Serrated Polyposis Syndrome in a Young Adolescent Patient

Serrated polyps are pathological neoplastic lesions in the colon with subtle gross morphology leading to underreporting during colonoscopy. While detection rates are increasing in average-risk adult screening colonoscopy, the rate of detection during pediatric colonoscopy is unknown. Serrated polyposis syndrome is characterized by the presence of multiple serrated polyps in the colon and an increased risk of developing colorectal cancer. Cancer prevention relies on early recognition, endoscopic clearance of all polyps > 5 mm, and continued interval surveillance or prophylactic colectomy. We report the diagnosis and management of serrated polyposis syndrome in a young adolescent patient and highlight the subtle features of serrated polyps that may go unrecognized leading to underreporting in childhood.

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.

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.

Immune Responses Vary in Preinvasive Colorectal Lesions by Tumor Location and Histology

Immune responses vary in colorectal cancers, which strongly influence prognosis. However, little is known about the variance in immune response within preinvasive lesions. The study aims to investigate how the immune contexture differs by clinicopathologic features (location, histology, dysplasia) associated with progression and recurrence in early carcinogenesis. We performed a cross-sectional study using preinvasive lesions from the surgical pathology laboratory at the Medical University of South Carolina. We stained the tissues with immunofluorescence antibodies, then scanned and analyzed expression using automated image analysis software. We stained CD117 as a marker of mast cells, CD4/RORC to indicate Th17 cells, MICA/B as a marker of NK-cell ligands, and also used antibodies directed against cytokines IL6, IL17A, and IFNγ. We used negative binomial regression analysis to compare analyte density counts by location, histology, degree of dysplasia adjusted for age, sex, race, and batch. All immune markers studied (except IL17a) had significantly higher density counts in the proximal colon than distal colon and rectum. Increases in villous histology were associated with significant decreases in immune responses for IL6, IL17a, NK ligand, and mast cells. No differences were observed in lesions with low- and high-grade dysplasia, except in mast cells. The lesions of the proximal colon were rich in immune infiltrate, paralleling the responses observed in normal mucosa and invasive disease. The diminishing immune response with increasing villous histology suggests an immunologically suppressive tumor environment. Our findings highlight the heterogeneity of the immune responses in preinvasive lesions, which may have implications for prevention strategies. PREVENTION RELEVANCE: Our study is focused on immune infiltrate expression in preinvasive colorectal lesions; our results suggest important differences by clinicopathologic features that have implications for immune prevention research.

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.

Can Aspirin Use Be Associated With the Risk or Prognosis of Bladder Cancer? A Case-Control Study and Meta-analytic Assessment

Aspirin, widely used to prevent cardiovascular disease, had been linked to the incidence of bladder cancer (BCa). Existing studies focusing on Chinese populations are relatively rare, especially for Northeast China. Meanwhile, relevant studies on the effects of aspirin on the occurrence or prognosis of BCa are inconsistent or even controversial. First, in the case control study, logistic regression analysis was used to investigate the association between aspirin intake and risk of BCa including 1121 patients with BCa and the 2242 controls. Subsequently, Kaplan-Meier curve and Cox regression analyses were applied to explore the association between aspirin intake and clinicopathological factors which may predict overall survival (OS) and recurrence-free survival (RFS) of BCa patients. Finally, we quantificationally combined the results with those from the published literature evaluating aspirin intake and its effects on the occurrence, outcome of surgery and prognosis of BCa by meta-analysis up to May 1, 2021.Our case-control study demonstrated that the regular use of aspirin was not associated with a reduced incidence of BCa (P=0.175). Stratified analyses of sex showed that aspirin intake did not lead to a lower risk of BCa in female patients (P=0.063). However, the male population who regularly took aspirin had a lower incidence of BCa (OR=0.748, 95% CI= 0.584-0.958, P=0.021). Subgroup analyses stratified by smoking found a significant reduction in the risk of BCa in current smokers with aspirin intake (OR=0.522, 95% CI=0.342-0.797, P=0.002). In terms of prognosis of BCa, patients with a history of aspirin intake did not had a markedly longer OS or RFS than those with no history of aspirin intake by Kaplan-Meier curves. Stratified analysis by sex showed no correlation between aspirin intake and the recurrence or survival of BCa for either male or female patients. However, in people younger than 68, aspirin intake seemed to have prolonged effects for overall survival (HR=3.876; 95% CI=1.326-11.325, P=0.019). Then, we performed a meta-analysis and the combined results from 19 articles and our study involving more than 39524 BCa cases indicated that aspirin intake was not associated with the occurrence of BCa (P=0.671). Subgroup analysis by whether regular use of aspirin, by the mean duration of use of aspirin, by sex, by smoking exposure, by research region and by study type also supported the above results. In terms of the impact of aspirin intake on the prognosis of patients with BCa, 11 articles and our study involving 8825 BCa cases were eligible. The combined results showed that patients with aspirin intake did not have significantly influence on survival, recurrence, progression and metastasis than those without aspirin intake. On the whole, both our retrospective study and literature meta-analysis suggested a lack of a strong relevant association between the use of aspirin and the incidence or prognosis of BCa. Thus, additional long-term follow-up prospective research is warranted to clarify the association of aspirin with BCa incidence and prognosis.

AGA Clinical Practice Update on Chemoprevention for Colorectal Neoplasia: Expert Review

DESCRIPTION

The purpose of this expert review is to describe the role of medications for the chemoprevention of colorectal neoplasia. Neoplasia is defined as precancerous lesions (e.g., adenoma and sessile serrated lesion) or cancer. The scope of this review excludes dietary factors and high-risk individuals with hereditary syndromes or inflammatory bowel disease.

METHODS

The best practice advice statements are based on a review of the literature to provide practical advice. A formal systematic review and rating of the quality of evidence or strength of recommendation were not performed. BEST PRACTICE ADVICE 1: In individuals at average risk for CRC who are (1) younger than 70 years with a life expectancy of at least 10 years, (2) have a 10-year cardiovascular disease risk of at least 10%, and (3) not at high risk for bleeding, clinicians should use low-dose aspirin to reduce CRC incidence and mortality. BEST PRACTICE ADVICE 2: In individuals with a history of CRC, clinicians should consider using aspirin to prevent recurrent colorectal neoplasia. BEST PRACTICE ADVICE 3: In individuals at average risk for CRC, clinicians should not use non-aspirin NSAIDs to prevent colorectal neoplasia because of a substantial risk of cardiovascular and gastrointestinal adverse events. BEST PRACTICE ADVICE 4: In individuals with type 2 diabetes, clinicians may consider using metformin to prevent colorectal neoplasia. BEST PRACTICE ADVICE 5: In individuals with CRC and type 2 diabetes, clinicians may consider using metformin to reduce mortality. BEST PRACTICE ADVICE 6: Clinicians should not use calcium or vitamin D (alone or together) to prevent colorectal neoplasia. BEST PRACTICE ADVICE 7: Clinicians should not use folic acid to prevent colorectal neoplasia. BEST PRACTICE ADVICE 8: In individuals at average risk for CRC, clinicians should not use statins to prevent colorectal neoplasia. BEST PRACTICE ADVICE 9: In individuals with a history of CRC, clinicians should not use statins to reduce mortality.

Serrated polyps of the colon and rectum: a concise review

"Serrated polyps" is the term used for epithelial lesions of the colon and rectum that have a "sawtooth" pattern on the polyp's surface and crypt epithelium. The so-called serrated pathway describes the progression of sessile serrated adenomas and traditional serrated adenomas to colorectal cancer. Said pathway is well recognized as an alternative mechanism of carcinogenesis and accounts for 15-30% of the cases of colorectal cancer. It also explains a large number of the cases of interval colorectal cancer. Thus, due to their usually aggressive and uncertain behavior, serrated polyps are of the utmost importance in colorectal cancer screening. Our aim was to review the history, current nomenclature, pathophysiology, morphology, treatment, and surveillance of serrated polyps.

Prevalence and risk factors for sessile serrated lesions in an average risk colorectal cancer screening population

BACKGROUND AND AIM

The reported prevalence and risk factors for sessile serrated lesions (SSLs) show significant variation. We aimed to specifically study the prevalence and potential risk factors of SSLs in an average risk colorectal cancer (CRC) screening population of Chinese subjects.

METHODS

This is a case-control study of prospectively collected data from a territory-wide colorectal screening program in Hong Kong. Information on risk factors was obtained from questionnaires completed prior to screening colonoscopy. We compared subjects with SSLs against controls without these lesions to identify potential risk factors using multivariable logistic regression.

RESULTS

Of 12 039 asymptomatic screening subjects, 6011 subjects received a screening colonoscopy with 2214 subjects (36.8%) having conventional adenomas, 486 subjects (8.1%) having hyperplastic polyps, and 85 subjects (1.4%) having SSLs only. Of these subjects, three had synchronous advanced adenomas and were excluded from the analysis. More than 60% of these lesions were in the proximal colon. We compared these 82 subjects with SSLs only and 3226 controls without any polyps. After multivariable logistic regression, age ≥ 66 years, smoking, and diabetes mellitus (DM) were significant independent risk factors for SSLs.

CONCLUSION

In this study, we report the prevalence of SSLs to be 1.4%. Age ≥ 66 years, smoking, and DM were independent risk factors for these lesions. Our findings provide relevant new data that should be taken into consideration when designing region-specific surveillance programs for SSLs with the ultimate goal of reducing the risk of CRC.

Aspirin reduces the incidence of metastasis in a pre-clinical study of Braf mutant serrated colorectal neoplasia

BACKGROUND

Aspirin reduces the incidence of conventional adenomas driven by APC mutation and thus colorectal cancer. The effect of aspirin on the ~20% of colorectal cancers arising via BRAF mutation is yet to be established.

METHODS

Braf^V637E/+;Villin-Cre^ERT2/+ mice were allocated to a control (n = 86) or aspirin-supplemented (n = 83) diet. After 14 months the incidence of murine serrated lesions, carcinoma and distant metastases were measured by histological examination. RNA was extracted from carcinomas from each cohort and subjected to sequencing to identify differentially expressed genes and molecular pathways.

RESULTS

Aspirin did not reduce the incidence of murine serrated lesions or carcinoma when compared to control, however, did significantly reduce lesion size (P = 0.0042). Among the mice with carcinoma there was a significant reduction in the incidence of distant metastasis with aspirin treatment (RR 0.69, 95% CI 0.48-0.90, P = 0.0134). Key pathways underlying metastasis of carcinoma cells include NOTCH, FGFR and PI3K signalling, were significantly downregulated in carcinomas sampled from mice on an aspirin-supplemented diet.

CONCLUSIONS

Aspirin reduces the incidence of metastatic Braf mutant carcinoma, although this is not due to a reduction in primary disease. The reduction in metastasis could be attributed to a delay or prevention of molecular changes within the primary site driving metastatic growth.

Multidisciplinary prevention and management strategies for colorectal cancer and cardiovascular disease

Colorectal cancer (CRC) and cardiovascular disease (CVD) are leading causes of morbidity and mortality worldwide. Their numerous shared and modifiable risk factors underscore the importance of effective prevention strategies for these largely preventable diseases. Conventionally regarded as separate disease entities, clear pathophysiological links and overlapping risk factors represent an opportunity for synergistic collaborative efforts of oncologists and cardiologists. In addition, current CRC treatment approaches can exert cardiotoxicity and thus increase CVD risk. Given the complex interplay of both diseases and increasing numbers of CRC survivors who are at increased risk for CVD, multidisciplinary cardio-oncological approaches are warranted for optimal patient care from primary prevention to acute disease treatment and long-term surveillance.

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.

Colorectal Cancer: In the Pursuit of Health Equity

Colorectal cancer mortality has decreased considerably following the adoption of national screening programs, yet, within at-risk subgroups, there continue to be measurable differences in clinical outcomes from variations in screening, receipt of chemotherapy, radiation or surgery, access to clinical trials, research participation, and survivorship. These disparities are well-described and some have worsened over time. Disparities identified have included race and ethnicity, age (specifically young adults), socioeconomic status, insurance access, geography, and environmental exposures. In the context of the COVID-19 pandemic, colorectal cancer care has necessarily shifted dramatically, with broad, immediate uptake of telemedicine, transition to oral medications when feasible, and considerations for sequence of treatment. However, it has additionally marginalized patients with colorectal cancer with historically disparate cancer-specific outcomes; among them, uninsured, low-income, immigrant, and ethnic-minority patients-all of whom are more likely to become infected, be hospitalized, and die of either COVID-19 or colorectal cancer. Herein, we outline measurable disparities, review implemented solutions, and define strategies toward ensuring that all have a fair and just opportunity to be as healthy as possible.

Colorectal cancer statistics, 2020

Colorectal cancer (CRC) is the second most common cause of cancer death in the United States. Every 3 years, the American Cancer Society provides an update of CRC occurrence based on incidence data (available through 2016) from population-based cancer registries and mortality data (through 2017) from the National Center for Health Statistics. In 2020, approximately 147,950 individuals will be diagnosed with CRC and 53,200 will die from the disease, including 17,930 cases and 3,640 deaths in individuals aged younger than 50 years. The incidence rate during 2012 through 2016 ranged from 30 (per 100,000 persons) in Asian/Pacific Islanders to 45.7 in blacks and 89 in Alaska Natives. Rapid declines in incidence among screening-aged individuals during the 2000s continued during 2011 through 2016 in those aged 65 years and older (by 3.3% annually) but reversed in those aged 50 to 64 years, among whom rates increased by 1% annually. Among individuals aged younger than 50 years, the incidence rate increased by approximately 2% annually for tumors in the proximal and distal colon, as well as the rectum, driven by trends in non-Hispanic whites. CRC death rates during 2008 through 2017 declined by 3% annually in individuals aged 65 years and older and by 0.6% annually in individuals aged 50 to 64 years while increasing by 1.3% annually in those aged younger than 50 years. Mortality declines among individuals aged 50 years and older were steepest among blacks, who also had the only decreasing trend among those aged younger than 50 years, and excluded American Indians/Alaska Natives, among whom rates remained stable. Progress against CRC can be accelerated by increasing access to guideline-recommended screening and high-quality treatment, particularly among Alaska Natives, and elucidating causes for rising incidence in young and middle-aged adults.

Body fatness over the life course and risk of serrated polyps and conventional adenomas

Serrated polyps (SPs) and conventional adenomas represent 2 distinct groups of colorectal premalignancy. The influence of early life adiposity on risk of these precursors remains unclear. Within the Nurses' Health Study, the Nurses' Health Study 2, and the Health Professionals Follow-up Study, we assessed body fatness during childhood using 9-level somatotype and obtained weight and body mass index (BMI) in adulthood. We used multivariable-adjusted logistic regression to examine the association of SPs and conventional adenomas with body fatness in early childhood (age 5), late childhood (age 10), early adulthood (age 18/21) and middle adulthood (baseline) and weight change during early-to-middle adulthood. During 18-20 years of follow-up, we documented 8,697 SPs and 10,219 conventional adenomas in 132,514 women; 2,403 SPs and 4,495 conventional adenomas in 29,207 men. We found a modest positive association of adiposity in early and late childhood with risk of SPs and conventional adenomas, with odds ratios ranging from 1.12 to 1.18 for comparison of extreme somatotypes groups. The associations were attenuated after adjusting for adulthood BMI but remained significant for conventional adenomas. No association with early life body fatness was found in men. Adulthood body fatness and weight change during early-to-middle adulthood showed positive relationships with SPs and conventional adenomas in both women and men, with stronger associations observed for SPs (p_{heterogeneity}  < 0.0001). Our findings indicated a potential role in development of colorectal cancer precursors of childhood body fatness in women, and early-to-middle adulthood weight gain and attained adiposity in both sexes.

Validation of serrated polyps (SPs) in Swedish pathology registers

Background

Little is known about the natural history of serrated polyps (SPs), partly due to the lack of large-scale epidemiologic data. In this study, we examined the validity of SP identification according to SNOMED (Systematised Nomenclature of Medicine) codes and free text from colorectal histopathology reports.

Methods

Through the ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden) study, we retrieved data on SPs from all pathology departments in Sweden in 2015–2017 by using SNOMED codes and free-text search in colorectal histopathology reports. Randomly selected individuals with a histopathology report of SPs were validated against patient charts using a structured, retrospective review.

Results

SPs were confirmed in 101/106 individuals with a histopathology report of SPs, yielding a positive predictive value (PPV) of 95% (95%CI = 89–98%). By year of diagnosis, the PPV was 89% (95%CI = 69–97%), 96% (95%CI = 81–99%) and 97% (95%CI = 89–99%) for individuals diagnosed before 2001 (n = 19), between 2001 and 2010 (n = 26) and after 2010 (n = 61), respectively. According to search method, the PPV for individuals identified by SNOMED codes was 100% (95%CI = 93–100%), and 93% (95%CI = 86–97%) using free-text search. Recorded location (colon vs. rectum) was correct in 94% of all SP histopathology reports (95%CI = 84–98%) identified by SNOMED codes. Individuals with SPs were classified into hyperplastic polyps (n = 34; 32%), traditional serrated adenomas (n = 3; 3%), sessile serrated adenomas/polyps (SSA/Ps) (n = 70; 66%), unspecified SPs (n = 3, 3%), and false positive SPs (n = 5, 5%). For individuals identified by SNOMED codes, SSA/Ps were confirmed in 49/52 individuals, resulting in a PPV of 94% (95%CI: 84–98%). In total, 57% had ≥2 polyps (1: n = 44, 2–3: n = 33 and ≥ 4: n = 27). Some 46% of SPs (n = 71) originated from the proximal colon and 24% were ≥ 10 mm in size (n = 37). Heredity for colorectal cancer, intestinal polyposis syndromes, or both was reported in seven individuals (7%). Common comorbidities included diverticulosis (n = 45, 42%), colorectal cancer (n = 19, 18%), and inflammatory bowel disease (n = 10, 9%).

Conclusion

Colorectal histopathology reports are a reliable data source to identify individuals with SPs.

IS THERE A DIFFERENCE BETWEEN RIGHT- VERSUS LEFT-SIDED COLON CANCERS? DOES SIDE MAKE ANY DIFFERENCE IN LONG-TERM FOLLOW-UP?

BACKGROUND

Since 1990 it was proposed that distal and proximal location of colon cancer might follow different biological, epidemiology, pathology and prognosis, probably due to embryologic different development of the two segments of the colon, which may represent two separate disease entities. These differences might have consequences for the treatment of patients with colorectal cancer.

AIM

To compare the characteristics between patients with right and left colon cancer, with severity and tumor characteristic that influence in the survival of these patients.

METHOD

Were evaluated the outcomes of surgical treatment of patients with colon cancer with data collected retrospectively from prospectively collected database.

RESULTS

The tumor's side did not influence survival time of patients with colon cancer (p=0.112) in the regression model. Only the diseases stage leads to influence on survival time; patients with right colon cancer have more advanced staging (III or IV) and present a risk of death greater in 3.23 times.

CONCLUSION

This analysis provides evidence that the prognosis of localized left-sided colon cancer is better compared to right-sided colon cancer. Also, the patients with right colon cancer have more advanced stage, mucinous tumor and are older.

Folic acid supplementation and risk of colorectal neoplasia during long-term follow-up of a randomized clinical trial

BACKGROUND

The Aspirin/Folate Polyp Prevention Study previously found folic acid increased risk of advanced and multiple colorectal adenomas during a surveillance colonoscopy interval starting about 3 y after randomization.

OBJECTIVE

We conducted secondary analyses to evaluate folic acid effects with additional follow-up after treatment was stopped.

METHODS

In total, 1021 participants recently diagnosed with colorectal adenomas were randomly assigned to 1 mg/d of folic acid (n = 516) or placebo (n = 505), with or without aspirin, beginning 6 July 1994. The original 3-y treatment period was extended into a subsequent colonoscopy interval, but eventually stopped prematurely on 1 October 2004. With additional post-treatment follow-up, a total of 663 participants who extended treatment completed a second colonoscopic surveillance interval after the initial 3-y follow-up. In addition, 490 participants provided information regarding a subsequent surveillance colonoscopy occurring before completion of follow-up on 31 May 2012, including 325 who had agreed to extended treatment. Study endpoints included conventional adenomas, sessile serrated adenomas/polyps (SSA/Ps), or colorectal cancer, and RRs with 95% CIs were adjusted for baseline characteristics associated with availability of follow-up.

RESULTS

Among those who extended treatment, any colorectal neoplasia was found in 118 (36%) participants assigned to placebo and 146 (43%) assigned to folic acid during the second surveillance interval (RR: 1.21; 95% CI: 0.99, 1.47; P = 0.06). Increased risk of SSA/P with extended folic acid supplementation was statistically significant during the second surveillance interval (RR: 1.94; 95% CI: 1.02, 3.68; P = 0.04). There was no evidence of post-treatment effects for any colorectal neoplasia (RR: 1.01; 95% CI: 0.80, 1.28; P = 0.94), and the post-treatment effect for SSA/P was no longer statistically significant (RR: 1.38; 95% CI: 0.59, 3.19; P = 0.46).

CONCLUSIONS

Delayed treatment effects were not observed, but folic acid may increase SSA/P risk. This trial was registered at clinicaltrials.gov as NCT00272324.

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.

Plasma Biomarkers of Insulin and the Insulin-like Growth Factor Axis, and Risk of Colorectal Adenoma and Serrated Polyp

BACKGROUND

Hyperinsulinemia, high insulin-like growth factor 1 (IGF1) levels, and low IGF binding protein 1 (IGFBP1) levels have been implicated in the relationship between obesity and increased risk of colorectal cancer (CRC). However, it remains inconclusive whether circulating biomarkers of insulin and the IGF axis are associated with conventional adenoma and serrated polyp, the two distinct groups of CRC precursors.

METHODS

We prospectively examined the associations of plasma C-peptide, IGF1, IGFBP1, IGFBP3, and IGF1 to IGFBP3 ratio with conventional adenoma and serrated polyp among 11 072 women from the Nurses' Health Studies. Multivariable logistic regression was used to calculate the odds ratio (OR) per 1-SD increase in each biomarker for overall risk of conventional adenoma and serrated polyp and according to polyp feature.

RESULTS

During 20 years of follow-up, we documented 1234 conventional adenomas and 914 serrated polyps. After adjusting for various lifestyle factors (including body mass index), higher concentrations of IGFBP1 were associated with lower risk of serrated polyp (OR = 0.84, 95% confidence interval = 0.75 to 0.95, P = .005). The association was particularly strong for large serrated polyp (≥10 mm) located in the distal colon and rectum (OR = 0.59, 95% confidence interval = 0.39 to 0.87, P = .01). In contrast, we did not find any statistically significant association between the biomarkers and conventional adenoma.

CONCLUSIONS

A higher plasma level of IGFBP1 was associated with lower risk of serrated polyp. Our findings support a potential role of IGFBP1 in the serrated pathway of CRC in women.

Common habitual behaviors and synchronous colorectal cancer risk: a retrospective case-control study

PURPOSE

The association of habitual behaviors with the prevalence of synchronous colorectal cancer (sCRC) is unknown. Here, we investigated whether these behaviors, which are known risk factors for colorectal polyps, may be related to sCRC risk.

METHODS

We enrolled 17,093 patients who underwent cancer treatment between January 1995 and December 2016 and examined the association of age, sex, familial history of hereditary colorectal cancer (CRC), and status of three common habitual behaviors (smoking and alcohol and coffee consumption) with the prevalence of sCRC.

RESULTS

Of the enrolled patients, 960 (5.6%) patients had sCRC. The independent risk factors for sCRC prevalence included advanced age, male sex, hereditary CRC, smoking, and daily alcohol consumption of more than one bottle (> 600 mL). Contrary to these factors, daily coffee consumption of more than one cup seemed to provide a protection from sCRC. In the Kaplan-Meier test, the significantly worse 5-year overall survival (OS) was noted in smokers with stage 0-III CRC. The effect of alcohol consumption on 5-year OS was significant in stages II and III. Compared with those without daily coffee consumption, patients with daily coffee consumption had significantly higher 5-year OS in stages I (93.0% vs. 86.4%), II (87.1% vs. 77.2%), III (71.5% vs. 61.9%), and IV (18.0% vs. 13.0%).

CONCLUSIONS

sCRC prevalence was significantly associated with habitual behaviors. Patients with smoking or with daily alcohol consumption of one bottle had higher sCRC prevalence than did those without these habits. Coffee consumption could be a protective factor for lowering sCRC risk.

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.

From "Serum Sickness" to "Xenosialitis": Past, Present, and Future Significance of the Non-human Sialic Acid Neu5Gc

The description of "serum sickness" more than a century ago in humans transfused with animal sera eventually led to identification of a class of human antibodies directed against glycans terminating in the common mammalian sialic acid N-Glycolylneuraminic acid (Neu5Gc), hereafter called "Neu5Gc-glycans." The detection of such glycans in malignant and fetal human tissues initially raised the possibility that it was an oncofetal antigen. However, "serum sickness" antibodies were also noted in various human disease states. These findings spurred further research on Neu5Gc, and the discovery that it is not synthesized in the human body due to a human-lineage specific genetic mutation in the enzyme CMAH. However, with more sensitive techniques Neu5Gc-glycans were detected in smaller quantities on certain human cell types, particularly epithelia and endothelia. The likely explanation is metabolic incorporation of Neu5Gc from dietary sources, especially red meat of mammalian origin. This incorporated Neu5Gc on glycans appears to be the first example of a "xeno-autoantigen," against which varying levels of "xeno-autoantibodies" are present in all humans. The resulting chronic inflammation or "xenosialitis" may have important implications in human health and disease, especially in conditions known to be aggravated by consumption of red meat. In this review, we will cover the early history of the discovery of "serum sickness" antibodies, the subsequent recognition that they were partly directed against Neu5Gc-glycans, the discovery of the genetic defect eliminating Neu5Gc production in humans, and the later recognition that this was not an oncofetal antigen but the first example of a "xeno-autoantigen." Further, we will present comments about implications for disease risks associated with red meat consumption such as cancer and atherosclerosis. We will also mention the potential utility of these anti-Neu5Gc-glycan antibodies in cancer immunotherapy and provide some suggestions and perspectives for the future. Other reviews in this special issue cover many other aspects of this unusual pathological process, for which there appears to be no other described precedent.

Calcium and vitamin D supplementation and increased risk of serrated polyps: results from a randomised clinical trial

OBJECTIVE

Serrated lesions such as sessile serrated adenomas or polyps (SSA/Ps) are important colorectal cancer precursors, but aetiological factors for these lesions are largely unknown. We aimed to determine the effects of calcium and vitamin D supplementation on the incidence of serrated polyps (SPs) in general and hyperplastic polyps and SSA/Ps specifically.

DESIGN

Participants with one or more adenoma at baseline were randomised to receive 1200 mg/day of elemental calcium, 1000 IU/day of vitamin D₃, both or neither agent. Treatment continued for 3 or 5 years, when risk of polyps was determined from surveillance colonoscopy (treatment phase). Outcomes after treatment ceased were also assessed (observational phase). Adjusted risk ratios (aRRs) of SPs were determined via multivariable generalised linear models.

RESULTS

SPs were diagnosed in 565 of 2058 (27.5%) participants during the treatment phase and 329/1108 (29.7%) during the observational phase. In total, 211 SSA/Ps were identified during follow-up. In the treatment phase, there was no effect of either calcium or vitamin D on incidence of SSA/Ps. However, during the later observational phase, we observed elevated risks of SSA/Ps associated with calcium alone and calcium+vitamin D treatment (aRR (95% CI): 2.65 (1.43 to 4.91) and 3.81 (1.25 to 11.64), respectively).

CONCLUSION

In a large multicentre chemoprevention study, we found evidence that calcium and vitamin D supplementation increased the risk of SSA/Ps. This appeared to be a late effect: 6-10 years after supplementation began. These possible risks must be weighed against the benefits of calcium and vitamin D supplementation. : Trial registration NUMBER: NCT00153816; Results.

The dark side of the colon: current issues surrounding the significance, prevalence, detection, diagnosis and management of serrated polyps

PURPOSE OF REVIEW

Hyperplastic polyps, once considered to have no malignant potential, are now recognized to be part of a larger group of polyps known as serrated polyps. Serrated polyps can progress to CRC through an epigenetic pathway known as CpG Island Methylator Phenotype (CIMP), characterized by hypermethylation of specific DNA regions such as the promoter regions of the DNA mismatch repair genes like MLH1. The CIMP pathway is tightly linked with mutations of the oncogene BRAF. There are three subtypes of serrated polyps - hyperplastic polyps, sessile serrated polyps (SSPs) and traditional serrated adenomas (TSAs). TSAs harbor cytologic dysplasia whereas hyperplastic polyps and SSPs are nondysplastic lesions. Currently, only SSPs and TSAs are believed to progress to CRC whereas hyperplastic polyps are thought to be benign with no malignant potential. This article will review the current evidence while highlighting some of the issues regarding serrated polyps.

RECENT FINDINGS

One challenge has been pathologically distinguishing hyperplastic polyps from SSPs, which is an important distinction, given the potential for progression of SSPs to CRC. Other challenges regarding serrated polyps include adequate detection and resection. Surveillance guideline recommendations for some serrated polyps have been changed in current guidelines to reflect the malignant potential, recommending closer surveillance intervals than the 10-year follow-up that has been traditionally provided for hyperplastic polyps.

SUMMARY

Given the difficulties in diagnosing as well as resecting, it is important for endoscopists to know how to detect, resect and manage follow-up in patients with serrated polyps.

Eicosapentaenoic acid and aspirin, alone and in combination, for the prevention of colorectal adenomas (seAFOod Polyp Prevention trial): a multicentre, randomised, double-blind, placebo-controlled, 2 × 2 factorial trial

BACKGROUND

The omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) and aspirin both have proof of concept for colorectal cancer chemoprevention, aligned with an excellent safety profile. Therefore, we aimed to test the efficacy of EPA and aspirin, alone and in combination and compared with a placebo, in individuals with sporadic colorectal neoplasia detected at colonoscopy.

METHODS

In a multicentre, randomised, double-blind, placebo-controlled, 2 × 2 factorial trial, patients aged 55-73 years who were identified during colonoscopy as being at high risk in the English Bowel Cancer Screening Programme (BCSP; ≥3 adenomas if at least one was ≥10 mm in diameter or ≥5 adenomas if these were <10 mm in diameter) were recruited from 53 BCSP endoscopy units in England, UK. Patients were randomly allocated (1:1:1:1) using a secure web-based server to receive 2 g EPA-free fatty acid (FFA) per day (either as the FFA or triglyceride), 300 mg aspirin per day, both treatments in combination, or placebo for 12 months using random permuted blocks of randomly varying size, and stratified by BCSP site. Research staff and participants were masked to group assignment. The primary endpoint was the adenoma detection rate (ADR; the proportion of participants with any adenoma) at 1 year surveillance colonoscopy analysed in all participants with observable follow-up data using a so-called at-the-margins approach, adjusted for BCSP site and repeat endoscopy at baseline. The safety population included all participants who received at least one dose of study drug. The trial is registered with the International Standard Randomised Controlled Trials Number registry, number ISRCTN05926847.

FINDINGS

Between Nov 11, 2011, and June 10, 2016, 709 participants were randomly assigned to four treatment groups (176 to placebo, 179 to EPA, 177 to aspirin, and 177 to EPA plus aspirin). Adenoma outcome data were available for 163 (93%) patients in the placebo group, 153 (85%) in the EPA group, 163 (92%) in the aspirin group, and 161 (91%) in the EPA plus aspirin group. The ADR was 61% (100 of 163) in the placebo group, 63% (97 of 153) in the EPA group, 61% (100 of 163) in the aspirin group, and 61% (98 of 161) in the EPA plus aspirin group, with no evidence of any effect for EPA (risk ratio [RR] 0·98, 95% CI 0·87 to 1·12; risk difference -0·9%, -8·8 to 6·9; p=0·81) or aspirin (RR 0·99 (0·87 to 1·12; risk difference -0·6%, -8·5 to 7·2; p=0·88). EPA and aspirin were well tolerated (78 [44%] of 176 had ≥1 adverse event in the placebo group compared with 82 [46%] in the EPA group, 68 [39%] in the aspirin group, and 76 [45%] in the EPA plus aspirin group), although the number of gastrointestinal adverse events was increased in the EPA alone group at 146 events (compared with 85 in the placebo group, 86 in the aspirin group, and 68 in the aspirin plus placebo group). Six upper-gastrointestinal bleeding events were reported across the treatment groups (two in the EPA group, three in the aspirin group, and one in the placebo group).

INTERPRETATION

Neither EPA nor aspirin treatment were associated with a reduction in the proportion of patients with at least one colorectal adenoma. Further research is needed regarding the effect on colorectal adenoma number according to adenoma type and location. Optimal use of EPA and aspirin might need a precision medicine approach to adenoma recurrence.

FUNDING

Efficacy and Mechanism Evaluation Programme, a UK Medical Research Council and National Institute for Health Research partnership.

Aspects of the Natural History of Sessile Serrated Adenomas/Polyps: Risk Indicators for Carcinogenesis in the Colorectal Mucosa?

BACKGROUND

Sessile serrated adenomas/polyps are potentially premalignant colorectal lesions that are precursors to colorectal cancer arising via CpG island methylator phenotype. They are caused by the combination of a BRAF mutation and promoter hypermethylation. DNA methylation is an age-dependent phenomenon in the right colon, and we would expect the occurrence and severity of serrated neoplasia to reflect this.

OBJECTIVE

The purpose of this study was to document the natural history of sessile serrated adenomas/polyps, including the ages at which they appear and the ranges of their number, size, and associated lesions.

DESIGN

This was a retrospective cohort study.

SETTINGS

The study was conducted at a tertiary referral center.

PATIENTS

Consecutive patients with sessile serrated adenomas/polyps removed between 2006 and 2015 were included. Patients with IBD, familial adenomatous polyposis, Lynch syndrome, serrated polyposis, and hereditary nonpolyposis colorectal cancer were excluded.

MAIN OUTCOME MEASURES

Age at which polyps were first diagnosed, location and size of polyps, demographics, and family history were measured.

RESULTS

A total of 440 patients had 668 sessile serrated adenomas/polyps, 257 (58%) also had ≥1 adenoma, and 28 (6%) had a history of colorectal cancer. Mean age at diagnosis was 68 ± 11 years, and 45% were men. Two hundred had had ≥1 colonoscopy before the diagnosis of the first sessile serrated adenomas/polyps. A total of 136 patients (31%) had multiple sessile serrated adenomas/polyps, including 24% synchronous and 10% metachronous. The range of total cumulative sessile serrated adenomas/polyps was from 1 to 7. A total of 554 (83%) of 668 sessile serrated adenomas/polyps were right sided; 48% were ≥1 cm diameter and 22% were >2 cm. The size of the first sessile serrated adenomas/polyps in those diagnosed under age 50 years averaged 10 mm, those between 50 and 60 years averaged 12 mm, and those between 60 and 70 years averaged 12 mm.

LIMITATIONS

No measurement of methylation or BRAF mutations in polyps or normal mucosa and a lack of subclassification of hyperplastic polyps limited this study.

CONCLUSIONS

The age of onset of sessile serrated adenomas/polyps varies, but the pattern is consistent with increasing methylation in the mucosa. Early negative colonoscopies predict a low risk of methylator cancers. See Video Abstract at http://links.lww.com/DCR/A736.

Calcium and vitamin D in the serrated neoplastic pathway: Friends or foes?

Sessile serrated adenoma/polyps (known as SSA/Ps) may play an important role in the development of interval colorectal cancer (CRC). These lesions are more difficult to detect with conventional endoscopy and they may quickly turn into CRC, especially when dysplasia has developed. Therefore, primary or secondary chemoprevention may be an appealing strategy at a population level. Calcium and vitamin D have been shown in epidemiological studies to reduce the risk of CRC and conventional adenomas, but the evidence regarding their effect on SSA/Ps is controversial. In this editorial we comment on the results of a recent randomized controlled trial investigating the effect of calcium and vitamin D on the development of serrated lesions, summarizing the possible antineoplastic mechanisms of calcium and vitamin D, and discussing the differences found with previous observational reports.

Association Between Risk Factors for Colorectal Cancer and Risk of Serrated Polyps and Conventional Adenomas

BACKGROUND & AIMS

Serrated polyps (SPs) and conventional adenomas are precursor lesions for colorectal cancer (CRC), but they are believed to arise via distinct pathways. We characterized risk factor profiles for SPs and conventional adenomas in a post hoc analysis of data from 3 large prospective studies.

METHODS

We collected data from the Nurses' Health Study, the Nurses' Health Study 2, and the Health Professionals Follow-up Study on subjects who developed SPs or conventional adenomas. Our analysis comprised 141,143 participants who had undergone lower gastrointestinal endoscopy, provided updated diet and lifestyle data every 2-4 years, and were followed until diagnosis of a first polyp. We assessed 13 risk factors for CRC in patients with SPs or conventional adenomas and examined the associations according to histopathology features.

RESULTS

We documented 7945 SPs, 9212 conventional adenomas, and 2382 synchronous SPs and conventional adenomas during 18-20 years of follow-up. Smoking, body mass index, alcohol intake, family history of CRC, and height were associated with higher risk of SPs and conventional adenomas, whereas higher intake of vitamin D and marine omega-3 fatty acid were associated with lower risk. The associations tended to be stronger for synchronous SPs and conventional adenomas. Smoking, body mass index, and alcohol intake were more strongly associated with SPs than conventional adenomas (P for heterogeneity <.05), whereas physical activity and intake of total folate and calcium were inversely associated with conventional adenomas but not SPs. For SPs and conventional adenomas, the associations tended to be stronger for polyps in the distal colon and rectum, of 10 mm or larger or with advanced histology.

CONCLUSIONS

In an analysis of data from 3 large prospective studies, we found that although SPs and conventional adenomas share many risk factors, some factors are more strongly associated with one type of lesion than the other. These findings provide support for the etiologic heterogeneity of colorectal neoplasia.

Sessile Serrated Adenomas: How to Detect, Characterize and Resect

Serrated polyps are important contributors to the burden of colorectal cancers (CRC). These lesions were once considered to have no malignant potential, but currently up to 30% of all CRC are recognized to arise from the serrated neoplasia pathway. The primary premalignant lesions are sessile serrated adenomas/polyps (SSA/Ps), although traditional serrated adenomas are relatively uncommon. Compared to conventional adenomas, SSA/Ps are morphologically subtle with indistinct borders, may be difficult to detect endoscopically, are more prevalent than previously thought, are associated with synchronous and metachronous advanced neoplasia, and have a higher risk of incomplete resection. Although many lesions remain “dormant,” progressive disease is associated with the development of dysplasia and more rapid progression to CRC. As a result, SSA/Ps are strongly implicated in the development of interval cancers. These factors represent unique challenges that require a meticulous approach to their management. In this review, we summarize the contemporary literature on the characterization, detection and resection of SSA/Ps.

Influence of Smoking, Body Mass Index, and Other Factors on the Preventive Effect of Nonsteroidal Anti-Inflammatory Drugs on Colorectal Cancer Risk

Nonsteroidal anti-inflammatory drugs' (NSAID) use has consistently been associated with lower risk of colorectal cancer; however, studies showed inconsistent results on which cohort of individuals may benefit most. We performed multivariable logistic regression analysis to systematically test for the interaction between regular use of NSAIDs and other lifestyle and dietary factors on colorectal cancer risk among 11,894 cases and 15,999 controls. Fixed-effects meta-analyses were used for stratified analyses across studies for each risk factor and to summarize the estimates from interactions. Regular use of any NSAID, aspirin, or nonaspirin NSAIDs was significantly associated with a lower risk of colorectal cancer within almost all subgroups. However, smoking status and BMI were found to modify the NSAID-colorectal cancer association. Aspirin use was associated with a 29% lower colorectal cancer risk among never-smokers [odds ratios (OR) = 0.71; 95% confidence intervals (CI): 0.64-0.79], compared with 19% and 17% lower colorectal cancer risk among smokers of pack-years below median (OR, 0.81; 95% CI, 0.71-0.92) and above median (OR, 0.83; 95% CI, 0.74-0.94), respectively (P interaction = 0.048). The association between any NSAID use and colorectal cancer risk was also attenuated with increasing BMI (P interaction = 0.075). Collectively, these results suggest that obese individuals and heavy smokers are unlikely to benefit as much as other groups from the prophylactic effect of aspirin against colorectal cancer.Significance: Obesity and heavy smoking attenuate the benefit of aspirin use for colorectal cancer prevention. Cancer Res; 78(16); 4790-9. ©2018 AACR.

Polyclonal human antibodies against glycans bearing red meat-derived non-human sialic acid N-glycolylneuraminic acid are stable, reproducible, complex and vary between individuals: Total antibody levels are associated with colorectal cancer risk

BACKGROUND

N-glycolylneuraminic acid (Neu5Gc) is a non-human red-meat-derived sialic acid immunogenic to humans. Neu5Gc can be metabolically incorporated into glycan chains on human endothelial and epithelial surfaces. This represents the first example of a "xeno-autoantigen", against which circulating human "xeno-autoantibodies" can react. The resulting inflammation ("xenosialitis") has been demonstrated in human-like Neu5Gc-deficient mice and contributed to carcinoma progression via antibody-mediated inflammation. Anti-Neu5Gc antibodies have potential as biomarkers for diseases associated with red meat consumption such as carcinomas, atherosclerosis, and type 2 diabetes.

METHODS

ELISA assays measured antibodies against Neu5Gc or Neu5Gc-glycans in plasma or serum samples from the Nurses' Health Studies, the Health Professionals Follow-up Study, and the European Prospective Investigation into Cancer and Nutrition, including inter-assay reproducibility, stability with delayed sample processing, and within-person reproducibility over 1-3 years in archived samples. We also assessed associations between antibody levels and coronary artery disease risk (CAD) or red meat intake. A glycan microarray was used to detected antibodies against multiple Neu5Gc-glycan epitopes. A nested case-control study design assessed the association between total anti-Neu5Gc antibodies detected in the glycan array assay and the risk of colorectal cancer (CRC).

RESULTS

ELISA assays showed a wide range of anti-Neu5Gc responses and good inter-assay reproducibility, stability with delayed sample processing, and within-person reproducibility over time, but these antibody levels did not correlate with CAD risk or red meat intake. Antibodies against Neu5Gc alone or against individual Neu5Gc-bearing epitopes were also not associated with colorectal cancer (CRC) risk. However, a sialoglycan microarray study demonstrated positive association with CRC risk when the total antibody responses against all Neu5Gc-glycans were combined. Individuals in the top quartile of total anti-Neu5Gc IgG antibody concentrations had nearly three times the risk compared to those in the bottom quartile (Multivariate Odds Ratio comparing top to bottom quartile: 2.98, 95% CI: 0.80, 11.1; P for trend = 0.02).

CONCLUSIONS

Further work harnessing the utility of these anti-Neu5Gc antibodies as biomarkers in red meat-associated diseases must consider diversity in individual antibody profiles against different Neu5Gc-bearing glycans. Traditional ELISA assays for antibodies directed against Neu5Gc alone, or against specific Neu5Gc-glycans may not be adequate to define risk associations. Our finding of a positive association of total anti-Neu5Gc antibodies with CRC risk also warrants confirmation in larger prospective studies.

Identification of risk factors for sessile and traditional serrated adenomas of the colon by using big data analysis

BACKGROUND AND AIM

Little is known about the risk factors associated with serrated polyps, because the early studies, which occurred before the new World Health Organization classification was introduced, included mixtures of serrated polyps. This study aimed to evaluate the risk factors associated with the presence of sessile serrated adenomas (SSAs) and traditional serrated adenomas (TSAs) using big data analytics.

METHODS

Using a case-control design, we evaluated the risk factors associated with the presence of SSAs and TSAs. Subjects who underwent colonoscopies from 2002 to 2012 as part of the comprehensive health screening programs undertaken at the Samsung Medical Center, Korea, participated in this study.

RESULTS

Of the 48 677 individuals who underwent colonoscopies, 183 (0.4%) had SSAs and 212 (0.4%) had TSAs. The multivariate analysis determined that being aged ≥ 50 years (odds ratio [OR] 1.91, 95% confidential interval [CI] 1.27-2.90, P = 0.002) and a history of colorectal cancer among first-degree relatives (OR 3.14, 95% CI 1.57-6.27, P = 0.001) were significant risk factors associated with the presence of SSAs and that being aged ≥ 50 years (OR 2.61, 95% CI 1.79-3.80, P < 0.001), obesity (OR 1.63, 95% CI 1.12-2.36, P = 0.010), and a higher triglyceride level (OR 1.63, 95% CI 1.12-2.36, P = 0.010) were independent risk factors associated with the presence of TSAs.

CONCLUSIONS

We used big data analytics to determine the risk factors associated with the presence of specific polyp subgroups, and individuals who have these risk factors should be carefully scrutinized for the presence of SSAs or TSAs during screening colonoscopies.

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.

Modifiable lifestyle factors associated with risk of sessile serrated polyps, conventional adenomas and hyperplastic polyps

OBJECTIVE

To identify modifiable factors associated with sessile serrated polyps (SSPs) and compare the association of these factors with conventional adenomas (ADs) and hyperplastic polyps (HPs).

DESIGN

We used data from the Tennessee Colorectal Polyp Study, a colonoscopy-based case-control study. Included were 214 SSP cases, 1779 AD cases, 560 HP cases and 3851 polyp-free controls.

RESULTS

Cigarette smoking was associated with increased risk for all polyps and was stronger for SSPs than for ADs (OR 1.74, 95% CI 1.16 to 2.62, for current vs never, ptrend=0.008). Current regular use of non-steroidal anti-inflammatory drugs was associated with a 40% reduction in SSP risk in comparison with never users (OR 0.68, 95% CI 0.48 to 0.96, ptrend=0.03), similar to the association with AD. Red meat intake was strongly associated with SSP risk (OR 2.59, 95% CI 1.41 to 4.74 for highest vs lowest intake, ptrend<0.001) and the association with SSP was stronger than with AD (ptrend=0.003). Obesity, folate intake, fibre intake and fat intake were not associated with SSP risk after adjustment for other factors. Exercise, alcohol use and calcium intake were not associated with risk for SSPs.

CONCLUSIONS

SSPs share some modifiable risk factors for ADs, some of which are more strongly associated with SSPs than ADs. Thus, preventive efforts to reduce risk for ADs may also be applicable to SSPs. Additionally, SSPs have some distinctive risk factors. Future studies should evaluate the preventive strategies for these factors. The findings from this study also contribute to an understanding of the aetiology and biology of SSPs.

Management of Serrated Polyps of the Colon

PURPOSE OF REVIEW

The purpose of this review is to summarize the management of serrated colorectal polyps (SPs), with a particular focus on the most common premalignant SP, sessile serrated adenoma or polyp (SSA/P). These lesions present a challenge for endoscopists with respect to detection and resection, and are also susceptible to pathologic misdiagnosis.

RECENT FINDINGS

Patients with SSA/Ps are at an increased risk of future colorectal neoplasia, including advanced polyps and cancer. Reasonable benchmarks for SP detection rates are 5-7% for SSA/Ps and 10-12% for proximal SPs. Certain endoscopic techniques such as chromoendoscopy, narrow band imaging, water immersion, and wide-angle viewing may improve SSA/P detection. Emerging endoscopic techniques such as underwater polypectomy, suction pseudopolyp technique, and piecemeal cold snare polypectomy are helpful tools for the endoscopist's armamentarium for removing SSA/Ps. Proper orientation of SSA/P specimens can improve the accuracy of pathology readings. Patients with confirmed SSA/Ps and proximal HPs should undergo surveillance at intervals similar to what is recommended for patients with conventional adenomas. Patients with SSA/Ps may also be able to lower their risk of future polyps by targeting modifiable risk factors including tobacco and alcohol use and high-fat diets. NSAIDs and aspirin appear to be protective agents. SPs and SSA/Ps in particular are important colorectal cancer precursors that merit special attention to ensure adequate detection, resection, and surveillance.

Statins dose-dependently exert a significant chemopreventive effect on colon cancer in patients with chronic obstructive pulmonary disease: A population-based cohort study

Purpose

We evaluated the chemopreventive effect of statins on colon cancer in patients with chronic obstructive pulmonary disease (COPD) and identified the statin exerting the strongest chemopreventive effect.

Methods

Using the National Health Insurance Research Database, we identified patients who received a COPD diagnosis in Taiwan between January 1, 2001, and December 31, 2012, and included them in the study cohort. Each patient was followed to assess the colon cancer risk and protective factors. A propensity score was derived using a logistic regression model to estimate the effect of statins by accounting for covariates predicted during the intervention (statins). To examine the dose–response relationship, we categorized statin doses into four groups in each cohort [<28, 28–90, 91–365, and >365 cumulative defined daily dose].

Results

Compared with the statin nonusers, the adjusted hazard ratio (aHR) for colon cancer decreased in the statin users (aHR = 0.52, 95% confidence interval = 0.44, 0.62). Hydrophilic statins exerted a stronger preventive effect against colon cancer. Regarding the statin type, lovastatin, pravastatin, and fluvastatin nonsignificantly reduced the colon cancer risk in the patients with COPD. Compared with the statin nonusers, the aHRs for colon cancer decreased in the individual statin users (rosuvastatin, simvastatin, and atorvastatin: aHRs = 0.28, 0.64, and 0.65, respectively). In the sensitivity analysis, statins dose-dependently reduced the colon cancer risk.

Conclusions

Statins dose-dependently exert significant chemopreventive effects on colon cancer in patients with COPD, with rosuvastatin exerting the largest chemopreventive effect.

The ethnic distribution of sessile serrated polyps in the United States is inversely associated with Helicobacter pylori prevalence

AIM

Little is known about the epidemiology of sessile serrated polyps (SSP). Our study aimed to investigate the influence of Helicobacter pylori gastritis and patient demographic characteristics (age, gender, ethnicity) on the prevalence of SSP using a large national database of patients undergoing bi-directional endoscopy.

METHOD

De-identified patient data were extracted from the Miraca Life Sciences electronic database of histopathological reports. Using multivariate logistic regression analysis, the influence of H. pylori gastritis and demographic characteristics on the occurrence of SSP were expressed as odds ratios (OR) with their 95% confidence intervals (CI).

RESULTS

The total study population comprised 228 506 subjects, of whom 28 890 carried a diagnosis of H. pylori gastritis and 11 285 SSP. Age (OR 4.35, 95% CI: 3.82-4.96), female gender (0.92, 0.88-0.95) and H. pylori gastritis (0.94, 0.88-0.99) exerted the strongest influence on the occurrence of SSP. In comparison with the population comprising Caucasians and African Americans, SSP were less common among subjects of Hispanic (0.67, 0.62-0.73), East Asian (0.59, 0.50-0.69), Indian (0.43, 0.27-0.64) or Middle Eastern descent (0.61, 0.41-0.87). All these ethnic subgroups were also characterized by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of SSP (R²  = 0.82, P < 0.001).

CONCLUSION

The prevalence of SSP within the United States is characterized by a marked ethnic variation. The inverse correlation between the prevalence of H. pylori and SSP suggests that gastric infection with H. pylori may be partly responsible for the observed ethnic distribution of SSP.

Alcohol, smoking and the risk of premalignant and malignant colorectal neoplasms

Colorectal cancer (CRC) is the third most common cancer worldwide and has a complex aetiology consisting of environmental and genetic factors. In this review, we evaluate the roles of alcohol and tobacco smoking in colorectal neoplasia. Alcohol intake and tobacco smoking are associated with modest, but significantly, increased risks of CRC, adenomatous and serrated polyps. There is consistent evidence of dose-response relationships for both alcohol and smoking, and risk of these neoplasms. Alcohol and smoking appear to be more strongly associated with colorectal polyp than CRC development, suggesting roles in the initiation of neoplastic growths. These lifestyle factors also seem more strongly related to adenomas and sessile serrated lesions than hyperplastic polyps, but further confirmation is required. The gastroenterology community has an important, yet currently underexploited, role to play addressing the modifiable factors associated with CRC and polyps. These behaviours include, but are not limited to, alcohol and smoking.