Differences in epidemiologic risk factors for colorectal adenomas and serrated polyps by lesion severity and anatomical site

Predictors for dMMR colorectal cancer in patients with serrated lesions and polyps - A register-based cohort study

BACKGROUND

Serrated lesions and polyps (SP) are precursors of up to 30 % of colorectal cancers (CRC) through the serrated pathway. This often entails early BRAF mutations and MLH1 hypermethylation leading to mismatch repair deficient (dMMR) CRC. We investigated predictors of dMMR CRC among patients with co-occurrence of CRC and SP to increase our knowledge on the serrated pathway.

METHODS

We used data from The Danish Pathology Registry and Danish Colorectal Cancer Groups Database from the period 2010-2021 to investigate risk factors for development of dMMR CRC. We used logistic regression models to identify difference in risk factors of developing dMMR CRC in comparison to CRC with proficient MMR (pMMR).

RESULTS

We included 3273 patients with a median age of 70.7 years [64.3,76.4] of which 1850 (56.5 %) were male. dMMR CRC was present in 592 patients (18.1 %), with loss of MLH1/PMS2 being most common. The risk of dMMR CRC was significantly higher in females OR 3.47 [2.87;4.20]. When adjusting for age, SP subtype, conventional adenomas (CA), anatomical location and lifestyle factors, female sex remained the strongest predictor OR 2.84 [2.27;3.56]. The presence of sessile serrated lesions with or without dysplasia was related to higher risk OR 1.60 [1.11;2.31] and OR 1.42 [1.11;1.82] respectively, while conventional adenomas constituted a lower risk OR 0.68 [0.55;0.84].

CONCLUSION

In conclusion we found several predictors of whom female sex had the strongest correlation with dMMR CRC in patients with SP.

Different modifiable risk factors for the development of non-advanced adenoma, advanced adenomatous lesion, and sessile serrated lesions, on screening colonoscopy

The development of premalignant colorectal polyps is significantly influenced by various lifestyle and modifiable risk factors. In our study, we used a large cohort of 9025 patients, who underwent screening colonoscopies at a university hospital, to assess the risk factors associated with the development of three different colorectal cancer precursor lesions: non-advanced adenomas (NAs), advanced adenomatous lesions (ADLs), and sessile serrated lesions (SSLs). Among the participants, 3641 had NAs, 836 had ADLs, and 533 had SSLs. We identified obesity, current smoking, and appendicular skeletal muscle mass as modifiable lifestyle risk factors that increase the development of NAs and ADLs (all P < 0.05). Furthermore, we found a positive correlation between the degree of obesity and an increased risk of developing NAs and ADLs (all P for trend < 0.001), while non-smoking was associated with a decreased risk (P for trend < 0.001 and 0.003, respectively). Smoking was the only modifiable risk factor for developing SSLs (adjusted odds ratio [aOR] 1.58; 95% confidence interval [CI] 1.20-2.07), and the risk was even higher in patients with metabolic syndrome (aOR 1.71; 95% CI 1.05-2.77). Addressing modifiable lifestyle factors such as smoking and obesity could play an important role in reducing the risk of both non-advanced and advanced adenomatous lesions. Smoking cessation is especially important as it is a significant modifiable risk factor for sessile serrated lesions.

Risk of colorectal neoplasia after removal of conventional adenomas and serrated polyps: a comprehensive evaluation of risk factors and surveillance use

BACKGROUND

Surveillance colonoscopy after polyp removal is recommended to prevent subsequent colorectal cancer (CRC). It is known that advanced adenomas have a substantially higher risk than non-advanced ones, but optimal intervals for surveillance remain unclear.

DESIGN

We prospectively followed 156 699 participants who had undergone a colonoscopy from 2007 to 2017 in a large integrated healthcare system. Using multivariable Cox proportional hazards regression we estimated the subsequent risk of CRC and high-risk polyps, respectively, according to index colonoscopy polyps, colonoscopy quality measures, patient characteristics and the use of surveillance colonoscopy.

RESULTS

After a median follow-up of 5.3 years, we documented 309 CRC and 3053 high-risk polyp cases. Compared with participants with no polyps at index colonoscopy, those with high-risk adenomas and high-risk serrated polyps had a consistently higher risk of CRC during follow-up, with the highest risk observed at 3 years after polypectomy (multivariable HR 5.44 (95% CI 3.56 to 8.29) and 8.35 (95% CI 4.20 to 16.59), respectively). Recurrence of high-risk polyps showed a similar risk distribution. The use of surveillance colonoscopy was associated with lower risk of CRC, with an HR of 0.61 (95% CI 0.39 to 0.98) among patients with high-risk polyps and 0.57 (95% CI 0.35 to 0.92) among low-risk polyps. Among 1548 patients who had high-risk polyps at both index and surveillance colonoscopies, 65% had their index polyps in the proximal colon and 30% had index and interval polyps in the same segments.

CONCLUSION

Patients with high-risk polyp findings were at higher risk of subsequent CRC and high-risk polyps and may benefit from early surveillance within 3 years. The subsite distribution of the index and recurrent high-risk polyps suggests the contribution of incomplete resection and missed lesions to the development of interval neoplasia.

Sporadic Polyps of the Colorectum

Colorectal polyps are common, and their diagnosis and classification represent a major component of gastrointestinal pathology practice. The majority of colorectal polyps represent precursors of either the chromosomal instability or serrated neoplasia pathways to colorectal carcinoma. Accurate reporting of these polyps has major implications for surveillance and thus for cancer prevention. In this review, we discuss the key histologic features of the major colorectal polyps with a particular emphasis on diagnostic pitfalls and areas of contention.

Intestinal "Piggybacking Lipoma", A Unique Lipoma Composed of Lipoma and Overlying Epithelial Lesions: A Case-control Study and Review of Literature

BACKGROUND/AIM

Lipomas are rare but the most common benign mesenchymal lesions of the gastrointestinal (GI) tract, composed of mature adipose cells. The "piggybacking lipoma" is formed by lipomas with overlying polypoid epithelial lesions, such as sessile serrated lesion, tubular adenoma, or hyperplastic polyp, and the literature on these lesions is limited. In this study, we systematically investigated the clinical, endoscopic, and pathologic characteristics of these unique lipomas.

PATIENTS AND METHODS

This is a single-institution retrospective study of gastrointestinal tract lipomas diagnosed from 2016-2021. Those with concurrent polypoid epithelial or mesenchymal lesions during the same endoscopic episode were included and reviewed in this study, and the lipomas were classified as "piggybacking lipoma" or "non-piggybacking lipoma" depending on whether the concurrent lesion was overlying the lipoma or was at a different location in the intestine. Demographic, clinical, and endoscopic data were obtained from electronic medical records.

RESULTS

A total of 100 lipomas with concurrent epithelial or mesenchymal lesions were included in this study. Among them, 21 cases were classified as "piggybacking lipoma" and 79 were classified as "non-piggybacking lipoma". Patients with piggybacking lipomas showed a female predilection, and were more likely to be symptomatic and less likely to exhibit classic endoscopic features of lipoma. Histologically, the piggybacking polyps showed overlying sessile serrated lesions (SSL) (76.2%) and tubular adenoma (TA) (19%), whereas the non-piggybacking group had differing characteristic lesions with TA (57.5%) and SSL (6.0%).

CONCLUSION

Piggybacking lipomas are rare lipomas with overlying polypoid epithelial lesions, most commonly SSL. They present different clinical, endoscopic, and pathologic features compared to non-piggybacking lipomas.

Prevalence, risk factors, and BRAF mutation of colorectal sessile serrated lesions among Vietnamese patients

BACKGROUND

Sessile serrated lesions (SSLs) are considered precancerous colorectal lesions that should be detected and removed to prevent colorectal cancer. Previous studies in Vietnam mainly investigated the adenoma pathway, with limited data on the serrated pathway.

AIM

To evaluate the prevalence, risk factors, and BRAF mutations of SSLs in the Vietnamese population.

METHODS

This is a cross-sectional study conducted on patients with lower gastrointestinal symptoms who underwent colonoscopy at a tertiary hospital in Vietnam. SSLs were diagnosed on histopathology according to the 2019 World Health Organization classification. BRAF mutation analysis was performed using the Sanger DNA sequencing method. The multivariate logistic regression model was used to determine SSL-associated factors.

RESULTS

There were 2489 patients, with a mean age of 52.1 ± 13.1 and a female-to-male ratio of 1:1.1. The prevalence of SSLs was 4.2% [95% confidence interval (CI): 3.5-5.1]. In the multivariate analysis, factors significantly associated with SSLs were age ≥ 40 [odds ratio (OR): 3.303; 95%CI: 1.607-6.790], male sex (OR: 2.032; 95%CI: 1.204-3.429), diabetes mellitus (OR: 2.721; 95%CI: 1.551-4.772), and hypertension (OR: 1.650, 95%CI: 1.045-2.605). The rate of BRAF mutations in SSLs was 35.5%.

CONCLUSION

The prevalence of SSLs was 4.2%. BRAF mutations were present in one-third of SSLs. Significant risk factors for SSLs included age ≥ 40, male sex, diabetes mellitus, and hypertension.

Association between lifestyle and dietary preference factors and conventional adenomas and serrated polyps

Introduction

Both conventional adenoma (AD) and serrated polyp (SP) were known precursor lesions of colorectal cancer (CRC). Modifiable lifestyle factors were significantly associated with CRC risk, but whether these factors were related to the risk of different precursors of CRC needed to be clarified. This study aimed to evaluate the risks of AD and SP caused by lifestyle factors and compare the risk differences between AD and SP.

Methods

The study population was from the CRC screening cohort in Hangzhou, China. A total of 458,457 eligible individuals volunteered to undergo initial screening including the fecal immunochemical test (FIT) and the CRC risk assessment. Finally, 13,993 participants who had undergone colonoscopy tests and had been diagnosed at designated hospitals were selected in this study. All participants were required to fill out a questionnaire during the initial screening for collecting their information. The generalized estimate equation (GEE) model was used to assess the association between lifestyle factors/dietary preferences and AD/SP.

Results

The body mass index (BMI) and smoking were positively associated with the risks of only SP (BMI: OR = 1.50, 95%CI: 1.23-1.84; smoking: OR = 1.29, 95%CI: 1.07-1.55), only AD (BMI: OR = 1.53, 95%CI: 1.28-1.82; OR = 1.24, 95%CI: 1.11-1.39), and synchronous SP and AD (BMI: OR = 1.97, 95%CI: 1.40-2.75; smoking: OR = 1.53, 95%CI: 1.27-1.85). In the case-group comparison, smoking was more strongly associated with the risk of synchronous SP and AD than only AD. Alcohol drinking was positively associated with the risk of AD (OR = 1.28, 95%CI: 1.14-1.44), but no statistically significant difference was observed in risks in the case-group comparison. Furthermore, whole-grain intake was associated with a decreased risk of only AD (OR = 0.78, 95%CI: 0.65-0.93). However, white meat intake was positively associated with risks of only SP when compared with AD cases (OR = 1.60, 95%CI: 1.15-2.23).

Conclusion

The current study identified common risk factors such as BMI and smoking as well as different risks of certain factors (e.g., alcohol drinking and whole-grain intake) for SP and AD. However, there were still some factors, especially diet-related factors, that have not been fully elucidated in their association with the two lesions. Further research is needed in future to confirm and develop prevention strategies for different lesions.

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.

Colorectal Cancer Risk Assessment and Precision Approaches to Screening: Brave New World or Worlds Apart?

Current colorectal cancer (CRC) screening recommendations take a "one-size-fits-all" approach using age as the major criterion to initiate screening. Precision screening that incorporates factors beyond age to risk stratify individuals could improve on current approaches and optimally use available resources with benefits for patients, providers, and health care systems. Prediction models could identify high-risk groups who would benefit from more intensive screening, while low-risk groups could be recommended less intensive screening incorporating noninvasive screening modalities. In addition to age, prediction models incorporate well-established risk factors such as genetics (eg, family CRC history, germline, and polygenic risk scores), lifestyle (eg, smoking, alcohol, diet, and physical inactivity), sex, and race and ethnicity among others. Although several risk prediction models have been validated, few have been systematically studied for risk-adapted population CRC screening. In order to envisage clinical implementation of precision screening in the future, it will be critical to develop reliable and accurate prediction models that apply to all individuals in a population; prospectively study risk-adapted CRC screening on the population level; garner acceptance from patients and providers; and assess feasibility, resources, cost, and cost-effectiveness of these new paradigms. This review evaluates the current state of risk prediction modeling and provides a roadmap for future implementation of precision CRC screening.

The comparison of risk factors for colorectal neoplasms at different anatomical sites

AIM

Both the clinical manifestation and molecular characteristics of colorectal cancer (CRC) vary according to the anatomical site. We explored the risk factors for four groups of colorectal neoplasms (CRN) at different anatomical sites.

METHODS

We extracted data from the database of Tianjin Colorectal Cancer Screening Program from 2010 to 2020. According to the CRN anatomical sites, patients were divided into four groups: the proximal colon group, the distal colon group, the rectum group, and the multiple colorectal sites. Binary logistic regression analysis was used to explore the differences in risk factors of CRN at different anatomical sites.

RESULTS

The numbers of patients with CRN in the proximal colon, distal colon, rectum, and multiple colorectal sites were 4023, 6920, 3657, and 7938, respectively. Male sex was associated with a higher risk from the proximal colon to the rectum. Advanced age and obesity were also significantly associated with overall colorectal CRN risk, but there were some differences between men and women. Smoking was associated with CRN risk only in the distal colon and rectum in both men and women. Frequent alcohol consumption and family history of CRC in first-degree relatives (FDRs) were associated with the risk of multisite colorectal CRN only in males.

CONCLUSIONS

We observed differences in advanced age, obesity, smoking, alcohol consumption, and family history of colorectal cancer at different anatomical sites of colorectal neoplasms. These factors vary by gender.

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.

Long-term Use of Hormone Replacement Therapy is Associated With a Lower Risk of Developing High-risk Serrated Polyps in Women

GOALS/BACKGROUND

Hormone replacement therapy (HRT) and parity have been suggested protective factors against the development of colorectal polyps. However, there are a limited number of studies that have examined the relationship of these factors with high-risk adenomatous polyps (HRAP) or high-risk serrated polyps (HRSP), which may have different causes and therefore implications for screening programs.

STUDY

Data from a cross-sectional study of 1384 women undergoing screening-related colonoscopy between 2008 and 2016 were analyzed. Modified Poisson regression models with robust error variance were used to determine the relative risk of developing adenomatous polyps, serrated polyps, HRAPs, and HRSPs associated with pregnancy, menopausal status, and the use of HRT (duration and type).

RESULTS

Women that used HRT for ≥6 years were at a significantly lower risk of developing a HRSP [risk ratios (RR): 0.53; 95% confidence interval (CI): 0.29-0.97]. Irrespective of the duration of use, the use of HRT that included progesterone alone or with estrogen was associated with a significantly lower risk of developing a HRSP (RR: 0.54; 95% CI: 0.30-0.95). The use HRT with progesterone for ≥6 years was associated with a nonsignificant lower risk of developing a HRSP (RR: 0.42; 95% CI: 0.17-1.04). None of the reproductive factors assessed or HRT were associated with the development of adenomatous polyps or HRAPs.

CONCLUSIONS

The results of this study suggests that the long-term use of HRT, and therapies that include progesterone are associated with a lower risk of developing HRSPs. These results could have implications for targeted screening for serrated polyps among women.

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.

Clinicopathological Correlates of Dysplastic Sessile Serrated Lesion: A Prospective Cohort Study With a High Detection Rate

Background and Aims

Sessile serrated lesions (SSLs) develop colorectal cancer (CRC), through a critical intermediary stage of SSL with dysplasia (SSLd). In this prospective observational study, we aimed to assess clinicopathological correlates of SSLd in the setting of a high lesion-detection rate.

Methods

Patients diagnosed with SSL and SSLd from February 2018 until January 2020 were prospectively recruited, and SSLd specimens were re-evaluated by 2 expert pathologists in a blinded manner. Associations were analyzed using multivariate logistic regression models.

Results

A total of 6425 patients underwent 7423 colonoscopies, and 2671 SSLs were resected from 1047 patients. The overall SSL detection rate per colonoscopy was 15.9%. The median age of patients with SSL was 54 years (interquartile range, 39-66), and 43.3% were male. After pathologist review, 24 SSLds were confirmed in 20 patients. The median size of SSLd was 8 mm (interquartile range, 5.75-15.25), and 13 of 24 SSLds were <10 mm in size. After multivariate analysis, older age (odds ratio = 1.07, 95% confidence interval = 1.03-1.1) and higher number of synchronous SSLs (odds ratio = 1.12, 95% confidence interval = 1.02-1.23) were associated with the presence of dysplasia. Patient sex and number and size of synchronous adenomas were not associated with the presence of SSLd. Seven of 20 patients with SSLd had synchronous or metachronous SSLd. Six of 20 patients with SSLd met the diagnostic criteria for serrated polyposis syndrome.

Conclusion

The overall SSL detection rate was 15.9%, and 0.9% of SSLs were dysplastic. Older age and higher number of synchronous SSL were risk factors for the presence of dysplasia in SSLs. Thirty percent of patients with SSLd had serrated polyposis syndrome, and 35% had multiple SSLd.

Healthy lifestyle and the risk of conventional adenomas and serrated polyps: Findings from a large colonoscopy screening population

Evidence on the link between healthy lifestyle and colorectal cancer (CRC) precursors is limited. Our study aimed to examine and compare the associations of healthy lifestyle with CRC precursors in adenoma (AD) -carcinoma and serrated pathways. A total of 24,480 participants including 6,309 ADs, 1,343 serrated polyps (SPs), and 16,828 polyp-free controls were included. A healthy lifestyle score (HLS) was constructed based on five lifestyle factors including cigarette smoking, alcohol drinking, physical activity, diet, and body weight, and categorized into least, slightly, moderately, and most healthy. Multivariable logistic regressions were used to estimate odds ratio (OR) and 95% confidence interval (CI). Inverse dose-response associations between the HLS and risk of ADs were observed (OR per 1 score increment for ADs: 0.82 [95% CI 0.79 - 0.84]; for SPs: 0.73 [95% CI 0.69 - 0.78]), and the association with SPs was more evident than with ADs (OR 0.90, 95% CI 0.85 - 0.96). Compared with participants with the least healthy lifestyle, those with the most healthy lifestyle had 47% lower risk of ADs (OR 0.53, 95% CI 0.47 - 0.59) and 70% lower risk of SPs (OR 0.30, 95% CI 0.23 - 0.39), respectively. These inverse associations were consistent across lesion stage and anatomic subsite and not modified by any stratification factors. The risk advancement periods for the most vs. the least healthy lifestyle were -9.49 years for ADs and -20.69 years for SPs. Our findings help confirm the preventive role of healthy lifestyle in colorectal carcinogenesis.

Evaluation of the Serrated Lesions Detection Rate and Its Role as a Colonoscopy Quality Criteria

Objectives To evaluate the serrated lesion detection rate in colonoscopy at a specialized clinic and its role as quality criteria for endoscopic examination.

Methods This is an observational cross-sectional study with all patients that underwent colonoscopy between October 2018 and May 2019, performed by an experimented physician. A questionnaire was answered before the examination by the patient, and another questionnaire after the colonoscopy was answered by the medical team. All polyps identified were removed and sent to the same pathologist for analysis.

Results A total of 1,000 colonoscopies were evaluated. The average age of the patients was 58.9 years old, and most of them were female (60.6%). In 62.5% of the procedures, polyps were removed, obtaining a total of 1,730 polyps, of which 529 were serrated lesions, being 272 sessile serrated lesions (SSL). This data resulted in a serrated lesion detection rate (SDR) of 29.2%, and of 14% when considering only the SSL detection rate (SSLDR). The right colon had higher rates, with 22.3% SDR and 15.3% SSLDR. Screening colonoscopies also presented a higher serrated detection rate, of 20%, followed by diagnostics and follow-up exams. Smoking was the only risk factor associated with higher serrated detection rate.

Conclusions The serrated lesion detection rate is higher than the ones already previously suggested and the have the higher rates were stablished in the right colon and on screening exams.

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.

Association between lifestyle and site-specific advanced colorectal lesions in screening with faecal immunochemical test and sigmoidoscopy

BACKGROUND

Lifestyle factors may help to identify individuals at high-risk for colorectal cancer (CRC).

AIMS

To examine the association between lifestyle, referral for follow-up colonoscopy and proximal neoplasia detection in CRC screening.

METHODS

In this observational study, 14,832 individuals aged 50-74 years were invited to faecal immunochemical test (FIT) or sigmoidoscopy screening. Advanced lesions (AL), including advanced adenomas, advanced serrated lesions and CRC were divided according to location: distal-only, or proximal with or without distal AL. We collected information on smoking habit, body mass index and alcohol intake through a questionnaire.

RESULTS

Out of 3,318 FIT and 2,988 sigmoidoscopy participants, 516 (16%) and 338 (11%), respectively, were referred for follow-up colonoscopy after a positive screening test. Two-hundred-and-fifty-six (4%) had distal-only and 119 (2%) proximal AL. In FIT participants, obesity and high alcohol intake were associated with proximal AL; odds ratio (95% confidence interval) 2.68 (1.36-5.26) and 2.16 (1.08-4.30), respectively. In sigmoidoscopy participants, current smoking was associated with proximal AL; 4.58 (2.24-9.38), and current smoking and obesity were associated with referral for colonoscopy; 2.80 (2.02-3.89) and 1.42 (1.01-2.00), respectively.

CONCLUSION

Current smoking, obesity and high alcohol intake were associated with screen-detected proximal colorectal AL. Current smoking and obesity were associated with referral for follow-up colonoscopy in sigmoidoscopy screening.

No Association Between Vitamin D Supplementation and Risk of Colorectal Adenomas or Serrated Polyps in a Randomized Trial

BACKGROUND & AIMS

The effects of vitamin D on risk of colorectal cancer precursors are not clear. We examined the influence of vitamin D supplementation on risk of colorectal adenomas and serrated polyps in a prespecified ancillary study of a large-scale prevention trial (the vitamin D and omegA-3 trial, VITAL) of individuals who were free of cancer and cardiovascular disease at enrollment.

METHODS

In VITAL trial, 25,871 adults with no history of cancer or cardiovascular disease (12,786 men 50 years or older and 13,085 women 55 years or older) were randomly assigned to groups given daily dietary supplements (2000 IU vitamin D₃ and 1 g marine n-3 fatty acid) or placebo. Patients were assigned to groups from November 2011 through March 2014 and the study ended on December 31, 2017. We confirmed conventional adenomas and serrated polyps by reviewing histopathology reports from participants who had reported a diagnosis of polyps and were asked by their doctors to return for a repeat colonoscopy or sigmoidoscopy in 5 years or less. We calculated the odds ratios (ORs) and 95% CIs by logistic regression, after adjusting for age, sex, n-3 treatment assignment, and history of endoscopy at time of randomization.

RESULTS

During a median follow-up of 5.3 years, we documented 308 cases of conventional adenomas in 12,927 participants in the vitamin D group and 287 cases in 12,944 participants in the placebo group (OR for the association of vitamin D supplementation with adenoma, 1.08; 95% CI, 0.92-1.27). There were 172 cases of serrated polyps in the vitamin D group and 169 cases in the placebo group (OR for the association of vitamin D supplementation with serrated polyp, 1.02; 95% CI, 0.82-1.26). Supplementation was not associated with polyp size, location, multiplicity, or histologic features. We found evidence for an interaction between vitamin D supplementation and serum level of 25-hydroxyvitamin D, measured in 15,787 participants at randomization. Among individuals with serum levels of 25-hydroxyvitamin D below 30 ng/mL, the OR associated with supplementation for conventional adenoma was 0.82 (95% CI, 0.60-1.13), whereas among individuals with serum levels of 25-hydroxyvitamin D above 30 ng/mL, the OR for conventional adenoma was 1.20 (95% CI, 0.92-1.55) (P for interaction = .07). There was a significant interaction between vitamin D supplementation and serum level of 25-hydroxyvitamin D in their association with advanced adenoma (P for interaction = .04).

CONCLUSIONS

Based on an ancillary study of data from the VITAL trial, daily vitamin D supplementation (2000 IU) was not associated with risk of colorectal cancer precursors in average-risk adults not selected for vitamin D insufficiency. A potential benefit for individuals with low baseline level of vitamin D requires further investigation. ClinicalTrials.gov number: NCT01169259.

Long term outcomes of colon polyps with high grade dysplasia following endoscopic resection

BACKGROUND

The risk of recurrent colonic adenoma associated with high-grade dysplasia (HGD) colon polyps at baseline colonoscopy remains unclear. We conducted a clinical cohort study with patients who underwent polypectomy during screen colonoscopy to assess recurrent colonic adenoma risk factors.

METHODS

11,565 patients at our facility underwent screen colonoscopy between September 1998 and August 2007. Data from patients with HGD colon polyps who had undergone follow-up colonoscopy were included for analysis.

RESULTS

Data from 211 patients was included. Rates of metachronous adenoma and advanced adenoma at follow-up were 58% and 20%, respectively. Mean follow-up period was 5.5 ± 1.8 (3-12) years. Univariate logistic regression analysis revealed that an adenoma count of ≥ 3 at baseline colonoscopy was strongly associated with overall recurrence, multiple recurrence, advanced recurrence, proximal recurrence, and distal adenoma recurrence with odds ratios of 4.32 (2.06-9.04 95% CI), 3.47 (1.67-7.22 95% CI), 2.55 (1.11-5.89 95% CI), 2.46 (1.16-5.22 95% CI), 2.89 (1.44-5.78 95% CI), respectively. Multivariate analysis revealed gender (male) [P = 0.010; OR 3.09(1.32-7.25 95% CI)] and adenoma count ≥ 3 [P = 0.002; OR 3.08(1.52-6.24 95% CI)] at index colonoscopy to be significantly associated with recurrence of advanced adenoma.

CONCLUSION

Recurrence of colonic adenoma at time of follow-up colonoscopy is common in patients who undergo polypectomy for HGD colon adenomas during baseline colonoscopy. Risk of further developing advanced adenomas is associated with gender and the number of colon adenomas present.

Underwater vs conventional endoscopic mucosal resection in treatment of colorectal polyps: A meta-analysis

BACKGROUND

Underwater endoscopic mucosal resection (UEMR) of colorectal lesions is emerging as an alternative method to conventional endoscopic mucosal resection (EMR); however, it is still controversial whether there is a difference in the effectiveness between UEMR and EMR.

AIM

To evaluate the effectiveness and safety of UEMR in the treatment of colorectal polyps.

METHODS

Clinical studies comparing the effectiveness or safety of UEMR in the treatment of colorectal polyps were searched in medical databases, including PubMed, Embase, Cochrane Library, CNKI, and Wanfang Data, monographs, theses, and papers presented at conferences. Statistical analyses were performed using Revman 5.3 software.

RESULTS

Seven non-randomized controlled trials and one randomized controlled trial met the inclusion criteria. In total, 1382 patients (1511 polyps) were included in the study, including 722 who received UEMR and 789 who received EMR. In the UEMR and EMR groups, the en bloc resection rates were 85.87% and 73.89%, respectively, with a relative risk (RR) value of 1.14 (95% confidence interval [CI]: 1.01-1.30; P < 0.05). In the sub-group analysis, the en bloc resection rate showed no statistically significant difference between the EMR and UEMR groups for polyps less than 20 mm in diameter. However, a statistically significant difference was found between the EMR and UEMR groups for polyps equal to or greater than 20 mm in diameter. The post-endoscopic resection recurrence rates at 3-6 mo of the UEMR and EMR groups were 3.26% and 15.17%, respectively, with an RR value of 0.27 (95%CI: 0.09-0.83; P < 0.05). The post-endoscopic resection recurrence rates of UEMR and EMR at 12 mo were 6.25% and 14.40%, respectively, with an RR value of 0.43 (95%CI: 0.20-0.92; P < 0.05). Additionally, the incidence of adverse events was 8.17% and 6.21%, respectively, with an RR value of 1.07 (95%CI: 0.50-2.30; P > 0.05).

CONCLUSION

UEMR is an effective technique for colorectal polyps and appears to have some advantages over EMR, particularly with regard to some treatment outcomes.

Association of low skeletal muscle mass with the presence of advanced colorectal neoplasm: integrative analysis using three skeletal muscle mass indices

AIM

This study aimed to evaluate an association between colorectal neoplasm (CRN) and skeletal muscle mass using three widely accepted skeletal muscle mass indices (SMIs) in a large population at average risk.

METHOD

We performed a cross-sectional study using a screening colonoscopy database of 33 958 asymptomatic subjects aged 40-75 years. Appendicular skeletal muscle mass (ASM) was measured using a bioelectrical impedance analyser. ASM adjusted for height squared (ASM/ht² ), weight (ASM/wt) and body mass index (ASM/BMI) were used as indices for muscle mass. Logistic regression models were used to evaluate the association between SMIs and CRN.

RESULTS

In a multivariable-adjusted model, the risk of an advanced CRN increased linearly with decreasing quartiles for all three SMIs. The adjusted odds ratios (ORs) for advanced CRN in quartiles 1, 2 and 3 of ASM/wt compared with that in quartile 4 were 1.279, 1.196 and 1.179, respectively (P_trend  = 0.017); for ASM/BMI, ORs were 1.307, 1.144 and 1.091, respectively (P_trend  = 0.002); and for ASM/ht² , ORs were 1.342, 1.169 and 1.062, respectively (P_trend  = 0.002). The risk of distally located advanced CRN was higher in quartile 1 than in quartile 4 for all three SMIs (ASM/wt, OR = 1.356; ASM/BMI, OR = 1.383; ASM/ht² , OR = 1.430).

CONCLUSION

Our study demonstrated that low skeletal muscle mass was consistently associated with the presence of advanced CRN in a population at average risk regardless of the operational definition of the SMI, and it was particularly associated with distal advanced CRN.

The incidence and risk factors of sessile serrated adenomas in left side colon cancer patients after curative surgery

Sessile serrated adenomas (SSAs) are precursors of colorectal cancer (CRC). However, there are limited data on detection rates of this premalignant lesion during colonoscopy surveillance in patients with a history of left side colonic resection for cancer. We aimed to identify the incidence and risk factors of SSAs in post-left side colectomy patients.We retrospectively reviewed the medical records of patients who had undergone left side colectomy for colon and rectal cancer between September 2009 and September 2016 and had at least 1 follow-up colonoscopy. Patient baseline characteristics, SSA diagnoses and characteristics, and colonoscopy information were collected.In total, 539 patients were enrolled. At the first follow-up (mean duration 11.5 months), 98 SSAs were identified (22.2%). At the second follow-up (mean duration 25.8 months), 51 SSAs were identified in 212 patients (24.0%). Multivariate analysis showed that alcohol intake (hazard ratio [HR] 1.524; 95% confidence interval [CI] .963-2.411, P = .041), excellent bowel preparation (HR 2.081; 95% CI 1.214-3.567, P = .049), and use of a transparent cap (HR 1.702; 95% CI 1.060-2.735, P = .013) were associated with higher SSA incidence in the first surveillance colonoscopy, while body mass index (BMI) ≥ 25.0 (HR 1.602; 95% CI 1.060-2.836) was associated with a significantly increased risk of SSAs in the second surveillance.Considering the endoscopic appearance of SSAs, adequate bowel preparation and use of transparent caps during postoperative surveillance colonoscopy can increase the diagnosis rate. Modification of alcohol intake and BMI may reduce the incidence of SSAs in left side colon cancer patients.

Yogurt consumption and colorectal polyps

Diet modifies the risk of colorectal cancer (CRC), and inconclusive evidence suggests that yogurt may protect against CRC. We analysed the data collected from two separate colonoscopy-based case-control studies. The Tennessee Colorectal Polyp Study (TCPS) and Johns Hopkins Biofilm Study included 5446 and 1061 participants, respectively, diagnosed with hyperplastic polyp (HP), sessile serrated polyp, adenomatous polyp (AP) or without any polyps. Multinomial logistic regression models were used to derive OR and 95 % CI to evaluate comparisons between cases and polyp-free controls and case-case comparisons between different polyp types. We evaluated the association between frequency of yogurt intake and probiotic use with the diagnosis of colorectal polyps. In the TCPS, daily yogurt intake v. no/rare intake was associated with decreased odds of HP (OR 0·54; 95 % CI 0·31, 0·95) and weekly yogurt intake was associated with decreased odds of AP among women (OR 0·73; 95 % CI 0·55, 0·98). In the Biofilm Study, both weekly yogurt intake and probiotic use were associated with a non-significant reduction in odds of overall AP (OR 0·75; 95 % CI 0·54, 1·04) and (OR 0·72; 95 % CI 0·49, 1·06) in comparison with no use, respectively. In summary, yogurt intake may be associated with decreased odds of HP and AP and probiotic use may be associated with decreased odds of AP. Further prospective studies are needed to verify these associations.

Colonoscopic techniques in polyp detection: An Egyptian study

INTRODUCTION AND AIMS

The polyp detection rate (PDR) is defined as the percentage of colonoscopies in which one or more polyps are detected, and has been shown to be highly correlated with the adenoma detection rate. The aim of the present study was to evaluate the PDR at the Endoscopy Unit of the Kasr Al-Ainy Hospital, Cairo University, Egypt, through the i-SCAN, Endocuff, and underwater colonoscopy techniques.

MATERIALS AND METHODS

The study was conducted on 100 Egyptian subjects over 50 years of age. Their polyp detection rate was measured through 4 different colonoscopic techniques. An equal number of patients were divided into 4 groups: i-SCAN, Endocuff, underwater colonoscopy, and controls. The control group was examined using standard white light colonoscopy. The colonoscopy evaluation included the type of agent utilized for bowel preparation, preparation grade, and colonoscopy withdrawal time.

RESULTS

The general PDR was 48%. The i-SCAN technique had the highest rate (56%), followed by the underwater (52%) and the Endocuff (48%) techniques.

CONCLUSION

The i-SCAN and underwater colonoscopy techniques produced higher PDR than the Endocuff-assisted and standard techniques, but with no statistical significance.

Colorectal Cancer Screening for the Serrated Pathway

Serrated polyps are classified into hyperplastic polyps, sessile serrated adenomas/polyps, and traditional serrated adenomas. Although all serrated polyps share characteristic colonic crypts serrations, distinguishing hyperplastic polyps from sessile serrated adenomas/polyps is challenging. Traditional serrated adenomas are cytologically dysplastic lesions; sessile serrated adenomas/polyps develop cytologic dysplasia as they progress to colorectal cancer. A flat and pale appearance of serrated polyps may make detection difficult. Endoscopic mucosal resection has higher rates of complete resection. Close surveillance is recommended for sessile serrated adenomas/polyps, sessile serrated adenomas/polyp with dysplasia, hyperplastic polyps ≥10 mm, and traditional serrated adenomas.

Associations between molecular characteristics of colorectal serrated polyps and subsequent advanced colorectal neoplasia

PURPOSE

BRAF mutation and DNA hypermethylation have linked sessile serrated adenomas/polyps (SSA/Ps) to serrated colorectal cancer (CRC) in cross-sectional studies, but they have not been evaluated in a longitudinal study. We aimed to evaluate the associations between molecular markers of serrated polyps and subsequent advanced colorectal neoplasia.

METHODS

Study subjects included Kaiser Permanente Washington members aged 20-75 years who received an index colonoscopy between 1/1/1998 and 12/31/2007 and had hyperplastic polyps (HPs) or SSA/Ps according to study pathology review. Polyps from index colonoscopies were removed and assayed for BRAF mutation, CpG island methylator phenotype (CIMP), and MLH1 methylation. Pathology reports and biopsies from the subsequent lower gastrointestinal endoscopy through 1/1/2013 were reviewed for advanced colorectal neoplasia. We identified additional incident CRC cases through linkage to the Seattle-Puget Sound Surveillance Epidemiology and End Results registry. We used generalized estimating equations to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for subsequent advanced colorectal neoplasia, comparing index serrated polyps with different molecular markers.

RESULTS

We included 553 individuals with index serrated polyps (420 HPs and 133 SSA/Ps) and 795 subsequent endoscopies. The prevalence of BRAF-mutant, CIMP-high, and MLH1-methylated serrated polyps were 51%, 4%, and 2%, respectively. BRAF and CIMP were not associated with subsequent advanced colorectal neoplasia. MLH1-methylated SSP/As were significantly more likely to have subsequent advanced neoplasia (OR = 4.66, 95% CI 1.06-20.51).

CONCLUSION

Our results suggest that BRAF-mutant and CIMP-high serrated polyps are not associated with subsequent advanced colorectal neoplasia. Among SSA/Ps, MLH1 methylation may be an important marker to identify high-risk CRC precursors.

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.

Effect of Gender and Age on the Correlation between Helicobacter pylori and Colorectal Adenomatous Polyps in a Chinese Urban Population: A Single Center Study

Objectives

To investigate whether Helicobacter pylori (H. pylori) infection increases the risk of colorectal adenomatous polyp (CAP) in the context of age and gender.

Methods

A total of 563 study subjects (male/female, 368/195) from Beijing, China, with higher nursing level who underwent colonoscopy were retrospectively collected. H. pylori and CAP were detected by carbon-13 urea breath test and colorectal colonoscopy. The correlations between the number, size, distribution, and pathological grade of CAP and H. pylori infection were analyzed. The population was further stratified by age and gender in order to examine the risk of H. pylori and CAP in the context of these variables. The influence of H. pylori on the risk of CAP was assessed by logistic regression model.

Results

315 participants were diagnosed with CAP, and 207 participants were classified as healthy controls. The prevalence of H. pylori in the CAP group was significantly higher than that in the healthy control group (119/315, 37.8% versus 44/207, 21.3%) (p < 0.001). The proportion of H. pylori positive plus CAP in participants <50 years old was significantly higher than that in participants >50 years old (87/250; 34.8% versus 32/65; 49.2%) (p < 0.001). The proportion of H. pylori positive plus CAP in participants <50 years old was significantly higher than that in participants >50 years old (87/250; 34.8% versus 32/65; 49.2%) (p < 0.001). The proportion of H. pylori positive plus CAP in participants <50 years old was significantly higher than that in participants >50 years old (87/250; 34.8% versus 32/65; 49.2%) (p < 0.001). The proportion of H. pylori positive plus CAP in participants <50 years old was significantly higher than that in participants >50 years old (87/250; 34.8% versus 32/65; 49.2%) (

Conclusions

H. pylori is a major risk factor for CAP. Further studies are needed to assess the effects of H. pylori treatment or persistent infection on the occurrence or recurrence of CAP.

Colorectal sessile serrated lesion with large size or synchronous neoplasm: a prospective study

BACKGROUND

Colorectal sessile serrated lesion (SSL) with synchronous neoplasm or large size are linked to higher risk of cancer, but their characteristics are unclear.

METHODS

We prospectively included consecutive colorectal hyperplasic polyp and SSL collected at our institution from August 2011 to August 2012. The following data were collected and analyzed: age, gender, polyp site, aggregated polyp size, history of polyp, and synchronous neoplasm.

RESULTS

We collected 437 specimens including 353 (80.8%) hyperplasic polyp and 84 (19.2%) SSL. Compared with hyperplasic polyp, SSL was independently associated with proximal colon [odds ratio (OR) 3.61, P< 0.001], larger size (OR 3.98, P< 0.001), but not history of polyp, age or gender. Large SSL (≥1 vs <1 cm) was associated with polyp site (P= 0.035) and synchronous advanced adenoma and cancer (P< 0.001). SSL with synchronous adenoma and cancer were more likely found in males (OR 1.91, P= 0.001), elderly (OR 1.02, P= 0.033), and patients with the index polyp in proximal colon (OR 1.32, P= 0.022), but not related to history of adenoma and cancer. Moreover, synchronous adenoma, SSL and cancer were independently associated with male gender (OR 1.90, P< 0.001), but surprisingly not older age, histology of index polyp (SSL vs hyperplasic polyp), index-polyp site or history of adenoma and cancer.

CONCLUSIONS

This prospective study shows male gender is associated with both synchronous adenoma and cancer, and synchronous adenoma, SSL and cancer, while index polyp site is associated with synchronous adenoma and cancer.

Colorectal cancer susceptibility variants and risk of conventional adenomas and serrated polyps: results from three cohort studies

BACKGROUND

Increasing evidence suggests that conventional adenomas (CAs) and serrated polyps (SPs) represent two distinct groups of precursor lesions for colorectal cancer (CRC). The influence of common genetic variants on risk of CAs and SPs remain largely unknown.

METHODS

Among 27 426 participants within three prospective cohort studies, we created a weighted genetic risk score (GRS) based on 40 CRC-related single nucleotide polymorphisms (SNPs) identified in previous genome-wide association studies; and we examined the association of GRS (per one standard deviation increment) with risk of CAs, SPs and synchronous CAs and SPs, by multivariable logistic regression. We also analysed individual variants in the secondary analysis.

RESULTS

During 18-20 years of follow-up, we documented 2952 CAs, 1585 SPs and 794 synchronous CAs and SPs. Higher GRS was associated with increased risk of CAs [odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.12-1.21] and SPs (OR = 1.09, 95% CI: 1.03-1.14), with a stronger association for CAs than SPs (Pheterogeneity=0.01). An even stronger association was found for patients with synchronous CAs and SPs (OR = 1.32), advanced CAs (OR = 1.22) and multiple CAs (OR = 1.25). Different sets of variants were associated with CAs and SPs, with a Spearman correlation coefficient of 0.02 between the ORs associating the 40 SNPs with the two lesions. After correcting for multiple testing, three variants were associated with CAs (rs3802842, rs6983267 and rs7136702) and two with SPs (rs16892766 and rs4779584).

CONCLUSIONS

Common genetic variants play a potential role in the conventional and serrated pathways of CRC. Different sets of variants are identified for the two pathways, further supporting the aetiological heterogeneity of CRC.

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.

Risk factors of traditional serrated adenoma and clinicopathologic characteristics of synchronous conventional adenoma

BACKGROUND AND AIMS

Traditional serrated adenoma (TSA) is rare and known to have a malignant potential. We aimed to investigate the prevalence and risk factors of TSA and compare the characteristics of synchronous conventional adenoma (AD) in patients with TSA with those of AD in patients with AD only.

METHODS

We reviewed medical records of 31,932 healthy subjects who underwent screening colonoscopy at a single hospital between 2012 and 2017.

RESULTS

TSA was observed in 116 patients (.4%). Among them, 47 patients (40.5%) had TSA only and 69 patients (59.5%) had synchronous AD. Multivariable analysis showed independent risk factors for TSA to include age ≥50 years (odds ratio [OR], 3.34; 95% confidence interval [CI], 1.72-6.49; P < .001), hypertension (OR, 2.07; 95% CI, 1.09-3.92; P = .026), and current smoking (OR, 2.58; 95% CI, 1.28-5.23; P = .008). There were significantly more ADs (2.5 ± 2.0 vs 1.8 ± 1.6, P = .009) and ADs were of larger size (6.7 ± 5.0 vs 5.3 ± 3.6 mm, P = .027) in TSA patients than in AD-only patients. Furthermore, advanced adenoma and high-risk adenoma were more frequently observed in TSA patients than in AD-only patients (24.2% vs 11.2%, P = .002; 43.5% vs 23.6%, P < .001).

CONCLUSIONS

The prevalence of TSA in healthy adults was .4%. Age ≥50 years, hypertension, and current smoking may be risk factors of TSA. Synchronous AD is often observed with TSA and may show more advanced features than those in AD-only patients.

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.

Physically active individuals have a 23% lower risk of any colorectal neoplasia and a 27% lower risk of advanced colorectal neoplasia than their non-active counterparts: systematic review and meta-analysis of observational studies

BACKGROUND

Few studies have examined the associations between physical activity (PA), sedentary behaviour (SB) and risk of colorectal neoplasia (CN).

METHODS

We systematically searched Medline, Embase, PsyInfo, Cochrane and other sources from their inception to 30 September 2018 for cohort, case-control and cross-sectional studies that evaluated these associations in asymptomatic, average-risk subjects. Random-effect models were used to estimate relative risks (RRs) of any-type CN, advanced CN, and non-advanced CN, respectively, in individuals with the highest versus the lowest level of PA and SB. Dose-response analyses and subgroup analyses were conducted. The I² statistic was used to examine heterogeneity among studies.

RESULTS

We identified 32 observational studies, including 17 cross-sectional studies, 10 case-control studies and five longitudinal studies. PA (highest vs lowest) was inversely associated with risk for any-type CN (n=23 studies) and advanced CN (n=15 studies), with a RR of 0.77 (95% CI=0.71 to 0.83, I²=57.5%) and 0.73 (95% CI=0.63 to 0.82, I²=45.5%), respectively. There was no association between PA and non-advanced CN (n=5 studies). There was an as association between PA and any-type CN in both sexes, and also for the distal colon. We found no dose-response relationship between PA and any-type or advanced CN. Based on three studies identified, SB time (longest vs shortest) was associated with an increased risk of advanced CN (RR=1.24, 95% CI 1.04 to 1.49, I²=14.4%). No publication bias was detected by Begg's test.

CONCLUSION

We report a 23% lower relative risk of any type of CN and a 27% lower risk of advanced CN in people with the highest level of PA compared with those in the lowest.

The association between colorectal sessile serrated adenomas/polyps and subsequent advanced colorectal neoplasia

PURPOSE

Colorectal cancer (CRC) screening guidelines recommend increased surveillance of individuals with sessile serrated adenomas/polyps (SSA/Ps), but there is uncertainty about the risk associated with SSA/Ps. We aimed to determine the association between SSA/Ps and subsequent advanced colorectal neoplasia.

METHODS

This case-control study included Kaiser Permanente Washington (KPWA) members who received an index colonoscopy between 1/1/1998 and 12/31/2007, and had hyperplastic polyps (HPs) or SSA/Ps but no conventional adenomas according to study pathologist histologic review. Subsequent pathology reports and biopsies through 1/1/2013 were reviewed for advanced colorectal neoplasia. We linked to the Seattle-Puget Sound Surveillance Epidemiology and End Results (SEER) registry to identify additional CRC cases. We used generalized estimating equations with a logit link to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for advanced colorectal neoplasia, comparing those with SSA/Ps to those with HPs.

RESULTS

There were 161 individuals with index SSA/Ps, 548 with HPs, and 918 subsequent endoscopies included in analyses. Of those with index SSA/Ps, 19 had subsequent advanced colorectal neoplasia; 39 with HPs had subsequent advanced colorectal neoplasia. Compared to those with HPs, those with SSA/Ps were not statistically significantly more likely to have subsequent advanced colorectal neoplasia (adjusted OR 1.79; CI 0.98-3.28). Polyp size ≥ 10 mm, right colon location, and the presence of multiple serrated polyps were also not associated with advanced colorectal neoplasia.

CONCLUSIONS

Our results suggest that there is not a strong association between SSA/Ps and subsequent advanced colorectal neoplasia during the 5 years following SSA/P removal.

Association Between Cigarette Smoking and Alcohol Consumption and Sessile Serrated Polyps in Subjects 30 to 49 Years Old

BACKGROUND & AIMS

We investigated the prevalence of sessile serrated polyps (SSPs) and the association between SSP risk and modifiable lifestyle factors in asymptomatic young adults.

METHODS

We performed a cross-sectional study using a screening colonoscopy database of 13,618 asymptomatic subjects age 30 to 49 years, and 17,999 subjects age 50 to 75 years. We investigated risk factors of SSP by multivariable analyses of clinical data that included cigarette smoking and alcohol consumption.

RESULTS

In subjects age 30 to 49 years, the prevalence of SSP was 2.0% (275 of 13,618 individuals). Of all SSPs, 40.7% (112 of 275 SSPs) were large (≥10 mm). Smoking for 20 or more pack-years was associated with overall SSPs (odds ratio [OR], 1.87; 95% CI, 1.17-2.99) and large SSPs (OR, 3.03; 95% CI, 1.62-5.66). The association between anatomic location and 20 or more pack-years of smoking was stronger for distal SSPs than for proximal SSPs (OR, 2.71; 95% CI, 1.27-5.77 vs OR, 1.60; 95% CI, 1.00-2.54). Cessation of smoking for 5 years or more decreased the risk of SSPs (OR, 0.49; 95% CI, 0.28-0.86) and of large SSPs (OR, 0.23; 95% CI, 0.10-0.54). Alcohol consumption was associated with large SSPs. These findings were similar for subjects age 50 to 75 years.

CONCLUSIONS

In an analysis of a screening colonoscopy database, we found that in asymptomatic young adults, smoking and alcohol consumption were associated with any SSPs and large SSPs. Cessation of smoking decreased the risk of SSPs. Therefore, early lifestyle modification may be recommended for primary prevention of SSPs in young adults.

Hormone replacement therapies, oral contraceptives, reproductive factors and colorectal adenoma risk: a systematic review and dose-response meta-analysis of observational studies

AIM

The association between the use of oral contraceptives and hormone replacement therapy (HRT) or other reproductive factors and the risk of colorectal adenoma (CRA) remains controversial. Our study aimed to review the evidence by conducting a dose-response meta-analysis to investigate this association.

METHODS

We searched PubMed and Embase databases for relevant studies published until May 2017. Traditional and dose-response meta-analyses were conducted. Sensitivity analysis was performed to evaluate the robustness of the results. Cumulative meta-analysis was used to assess the risk of different oral contraceptive formulations or generations.

RESULTS

A total of 19 observational studies, with 21 923 CRA cases and 1 030 711 participants, were included in the meta-analysis. Ever HRT use showed a potential inverse association with CRA risk [relative risk (RR) 0.83, 95% CI 0.70-1.00]. The dose-response meta-analysis further demonstrated that HRT use could reduce CRA risk. Compared with no HRT use, the predicted RRs were 0.82 (95% CI 0.67-0.99), 0.76 (95% CI 0.59-0.98) and 0.77 (95% CI 0.62-0.96) for 3, 6 and 9 years of HRT use, respectively. All other factors were not statistically significantly associated with CRA risk.

CONCLUSIONS

This study indicated that only HRT use might reduce the risk of developing CRA. Any advice regarding HRT use to prevent CRA should be tailored to the individual risks and potential benefits. Large, well-designed prospective studies with long-term follow-up are required to further clarify the aetiology of CRA.

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.

Is There Etiologic Heterogeneity between Subtypes of Childhood Acute Lymphoblastic Leukemia? A Review of Variation in Risk by Subtype

Although substantial advances in the identification of cytogenomic subtypes of childhood acute lymphoblastic leukemia (ALL) have been made in recent decades, epidemiologic research characterizing the etiologic heterogeneity of ALL by subtype has not kept pace. The purpose of this review is to summarize the current literature concerning subtype-specific epidemiologic risk factor associations with ALL subtype defined by immunophenotype (e.g., B-cell vs. T-cell) and cytogenomics (including gross chromosomal events characterized by recurring numerical and structural abnormalities, along with cryptic balanced rearrangements, and focal gene deletions). In case-control analyses investigating nongenetic risk factors, home paint exposure is associated with hyperdiploid, MLL-rearranged, and ETV6-RUNX1 subtypes, yet there are few differences in risk factor associations between T- and B-ALL. Although the association between maternal smoking and ALL overall has been null, maternal smoking is associated with an increasing number of gene deletions among cases. GWAS-identified variants in ARID5B have been the most extensively studied and are strongly associated with hyperdiploid B-ALL. GATA3 single nucleotide variant rs3824662 shows a strong association with Ph-like ALL (OR = 3.14). However, there have been relatively few population-based studies of adequate sample size to uncover risk factors that may define etiologic heterogeneity between and within the currently defined cytogenomic ALL subtypes.

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.

Risk factors for advanced colorectal neoplasms in the proximal colon in 6218 subjects undergoing complete colonoscopy

BACKGROUND AND AIM

Proximal migration of colonic lesion has been observed; however, risk factors of lesions in the proximal colon remain uncertain. This study aimed to investigate risk factors of lesions in the proximal colon.

METHODS

Consecutive subjects with complete colonoscopy were included. The primary outcome was risk factors associated with advanced neoplasm (AN) and serrated lesion in the proximal colon. Age, gender, first-degree relative (FDR) with colorectal cancer (CRC), smoking, alcohol consumption, body mass index, hypertension, diabetes, ischemic heart disease, and the use of aspirin, non-steroidal anti-inflammatory drug, and anticoagulants were fitted into a regression model, with reference to subjects without colonic finding. Results were measured by odds ratio (OR) with 95% confidence interval (CI).

RESULTS

Among 6218 subjects (mean age 56.65 ± 6.15 years; 46.8% male), 352 (5.7%) had AN; 809 (13.0%) had serrated lesions, and 3648 (58.7%) had no colonic finding. There were 148 (2.4%) and 235 (3.8%) subjects having AN and serrated lesion in the proximal colon. Age ≥ 50 (OR: 13.30; 95% CI: 1.85-95.76), male gender (OR: 1.82; 95% CI: 1.26-2.62), FDR with CRC (OR: 2.12; 95% CI: 1.43-3.15), and hypertension (OR: 1.86; 95% CI: 1.30-2.68) were associated with AN in the proximal colon. Age ≥ 50 (OR: 5.72; 95% CI: 2.10-15.53), male gender (OR: 1.54; 95% CI: 1.15-2.05), and smoking (OR: 1.85; 95% CI: 1.23-2.79) increased risk of serrated lesions in the proximal colon.

CONCLUSION

Age ≥ 50 and male gender were associated with both proximally located AN and serrated lesion; FDR with CRC and hypertension increased the risk of proximal AN, while ever smoking increased the risk of proximal serrated lesion. FDR with CRC was not associated with serrated lesion.

Methylation of tumor suppressor genes and risk factors of colorectal cancer

Although the diagnostic methods and treatment options are continuously optimized, the incidence and mortality of colorectal cancer (CRC) are still rising. Therefore, "preventive treatment of disease" is the key to solving this problem. In recent years, hypermethylation of promoter CpG islands (CGIs) in tumor suppressor genes has been a hot research topic because it is reversible and early events in the development of CRC, and affects drug resistance, disease treatment, and patient prognosis. CRC risk factors such as poor dietary choice, lack of physical activity, excessive drinking, and unhealthy weight can regulate promoter CGI hypermethylation, which will help develop new methylation-related cancer prevention strategies. This article mainly introduces the significance and regulatory mechanism of methylation of tumor suppressor genes and its relationship with risk factors in CRC.

Smoking and Other Risk Factors in Individuals With Synchronous Conventional High-Risk Adenomas and Clinically Significant Serrated Polyps

BACKGROUND AND AIMS

Serrated polyps (SPs) and conventional high-risk adenomas (HRAs) derive from two distinct biological pathways but can also occur synchronously. Adults with synchronous SPs and adenomas have been shown to be a high-risk group and may have a unique risk factor profile that differs from adults with conventional HRAs alone. We used the population-based New Hampshire Colonoscopy Registry (NHCR) to examine the risk profile of individuals with synchronous conventional HRAs and SPs.

METHODS

Our study population included 20,281 first time screening colonoscopies from asymptomatic NHCR participants 40 years or older between 2004-15. Exams were categorized by findings: (1) normal, (2) HRA only (adenomas ≥ 1 cm, villous, high grade dysplasia, multiple adenomas ( > 2) and adenocarcinoma), (3) clinically significant SP (CSSP) only (any hyperplastic polyp ≥ 1 cm, sessile serrated adenomas/polyps or traditional serrated adenomas), and (4) synchronous HRA + CSSP. Risk factors examined included exposure of interest, smoking (never, past, and current/pack years), as well as age, sex, alcohol, education, and family history of colorectal cancer (CRC). Multivariable unconditional logistic regression tested the relation of risk factors with having synchronous HRA + CSSP versus having a normal exam or HRA alone.

RESULTS

Among NHCR participants with 18,354 screening colonoscopies (with complete smoking, sex, bowel preparation data, and adequate preparation) there were 16,495 normal; 1309 HRA alone; 461 CSSP alone, and 89 synchronous HRA + CSSP. Current smoking was associated with an almost threefold increased risk for HRA or CSSP, and an eightfold risk for synchronous HRA + CSSP (aOR = 8.66; 95% CI: 4.73-15.86) compared to normal exams. Adults with synchronous HRA + CSSP were threefold more likely to be current smokers than those with HRA alone (aOR = 3.27; 95% CI:1.74-6.16).

CONCLUSIONS

Our data suggest that current smokers may be at a higher risk for synchronous CSSP + HRA even when compared to having HRA alone.

Endoscopist factors that influence serrated polyp detection: a multicenter study

BACKGROUND

Serrated polyps are important colorectal cancer precursors that are variably detected during colonoscopy. We measured serrated polyp detection rate (SPDR) in a large, multicenter, cross-sectional study of colonoscopy quality to identify drivers of SPDR variation.

METHODS

Colonoscopy and pathology reports were collected for a 2-year period (10/2013-9/2015) from four sites across the United States. Data from reports, including size, location, and histology of polyps, were abstracted using a validated natural language processing algorithm. SPDR was defined as the proportion of colonoscopies with ≥ 1 serrated polyp (not including hyperplastic polyps). Multivariable logistic regression was performed to determine endoscopist characteristics associated with serrated polyp detection.

RESULTS

A total of 104 618 colonoscopies were performed by 201 endoscopists who varied with respect to specialty (86 % were gastroenterologists), sex (18 % female), years in practice (range 1 - 51), and number of colonoscopies performed during the study period (range 30 - 2654). The overall mean SPDR was 5.1 % (SD 3.8 %, range 0 - 18.8 %). In multivariable analysis, gastroenterology specialty training (odds ratio [OR] 1.89, 95 % confidence interval [CI] 1.33 - 2.70), fewer years in practice (≤ 9 years vs. ≥ 27 years: OR 1.52, 95 %CI 1.14 - 2.04)], and higher procedure volumes (highest vs. lowest quartile: OR 1.77, 95 %CI 1.27 - 2.46)] were independently associated with serrated polyp detection.

CONCLUSIONS

Gastroenterology specialization, more recent completion of training, and greater procedure volume are associated with serrated polyp detection. These findings imply that both repetition and training are likely to be important contributors to adequate detection of these important cancer precursors. Additional efforts to improve SPDR are needed.

Smoking Habits are Strongly Associated With Colorectal Polyps in a Population-based Case-control Study

GOALS

The goal of this study is to test the association between lifetime smoking habits and colorectal polyps of different classifications.

BACKGROUND

Smoking is an established risk factor for several cancers, including colorectal cancer. However, the association between lifetime smoking habits including intensity, duration, and cessation, and premalignant colorectal polyps is yet to be established.

STUDY

A case-control study among 828 consecutive subjects aged 40 to 70 years, undergoing screening or diagnostic colonoscopy. Exclusion criteria were: medically treated diabetes, colectomy, and belonging to colorectal cancer high risk group. Polyps were stratified according to histology (serrated or adenomatous polyp) and location. All participants underwent anthropometric measurements and a structured medical and lifestyle interview.

RESULTS

Current-smoking was more strongly associated with increased odds for distal rather than proximal polyps [odds ratio (OR), 4.00; 95% confidence interval (CI), 2.40-6.68 and OR, 2.52; 95% CI, 1.46-4.36, respectively], with serrated-polyps rather than adenomas (OR, 6.36; 95% CI, 2.77-14.57 and OR, 3.01; 1.90-4.74, respectively). All levels of smoking intensity (daily cigarettes) were associated with colorectal polyps. A dose-response association was seen between smoking duration and colorectal polyps. Smoking duration of ≥20 years was strongly associated with distal polyps (OR, 4.01; 95% CI, 1.62-9.84), independently of potential confounders, smoking intensity and years since smoking cessation. All associations were stronger for distal serrated polyps.

CONCLUSIONS

Smoking duration is associated with colorectal plyps, independently of other potential confounders, smoking intensity, and cessation. The association is stronger with distal rather than proximal polyps, and with serrated polyps rather than adenomas.