Cigarette smoking and adenomatous polyps: a meta-analysis

DNA-methylation variability in normal mucosa: a field cancerization marker in patients with adenomatous polyps

BACKGROUND

The phenomenon of field cancerization reflects the transition of normal cells into those predisposed to cancer. Assessing the scope and intensity of this process in the colon may support risk prediction and colorectal cancer prevention.

METHODS

The Swiss Epigenetic Colorectal Cancer Study (SWEPIC) study, encompassing 1111 participants for DNA methylation analysis and a subset of 84 for RNA sequencing, was employed to detect field cancerization in individuals with adenomatous polyps (AP). Methylation variations were evaluated for their discriminative capability, including in external cohorts, genomic localization, clinical correlations, and associated RNA expression patterns.

RESULTS

Normal cecal tissue of individuals harboring an AP in the proximal colon manifested dysregulated DNA methylation compared to tissue from healthy individuals at 558 unique loci. Leveraging these adenoma-related differentially variable and methylated CpGs (aDVMCs), our classifier discerned between healthy and AP-adjacent tissues across SWEPIC datasets (cross-validated area under the receiver operating characteristic curve [ROC AUC] = 0.63-0.81), including within age-stratified cohorts. This discriminative capacity was validated in 3 external sets, differentiating healthy from cancer-adjacent tissue (ROC AUC = 0.82-0.88). Notably, aDVMC dysregulation correlated with polyp multiplicity. More than 50% of aDVMCs were significantly associated with age. These aDVMCs were enriched in active regions of the genome (P < .001), and associated genes exhibited altered expression in AP-adjacent tissues.

CONCLUSIONS

Our findings underscore the early onset of field cancerization in the right colon during the neoplastic transformation process. A more extensive validation of aDVMC dysregulation as a stratification tool could pave the way for enhanced surveillance approaches, especially given its linkage to adenoma emergence.

Derivation and validation of a nomogram incorporating modifiable lifestyle factors to predict development of colorectal adenomas after negative index colonoscopy

This retrospective cohort study aimed to identify baseline patient characteristics involving modifiable lifestyle factors that are associated with the development of colorectal adenomas, and establish and validate a nomogram for risk predictions among high-risk populations with negative index colonoscopy. A total of 83,076 participants who underwent an index colonoscopy at the Tianjin Union Medical Center between 2004 and 2019 were collected. According to meticulous inclusion and exclusion criteria, 249 subjects were enrolled and categorized into the primary and validation cohorts. Based on the primary cohort, we utilized the LASSO-Cox regression and the univariate/multivariate Cox proportional hazards (Cox-PH) regression parallelly to select variables, and incorporated selected variables into two nomogram models established using the multivariate Cox-PH regression. Comparison of the Akaike information criterion and the area under the receiver operating characteristic curve of the two models demonstrated that the nomogram model constituted by four covariates retained by the LASSO-Cox regression, including baseline age, body mass index, physical activity and family history of colorectal cancer (CRC) in first-degree relatives, performed better at predicting adenoma-free survival probabilities. Further validation including the concordance index, calibration plots, decision curve analysis and Kaplan-Meier survival curves also revealed good predictive accuracy, discriminating ability, clinical utility and risk stratification capacity of the nomogram model. Our nomogram will assist high-risk individuals with negative index colonoscopy to prevent colorectal adenoma occurrence and CRC morbidity with improved cost-effectiveness.

Systematic replication of smoking disease associations using survey responses and EHR data in the All of Us Research Program

OBJECTIVE

The All of Us Research Program (All of Us) aims to recruit over a million participants to further precision medicine. Essential to the verification of biobanks is a replication of known associations to establish validity. Here, we evaluated how well All of Us data replicated known cigarette smoking associations.

MATERIALS AND METHODS

We defined smoking exposure as follows: (1) an EHR Smoking exposure that used International Classification of Disease codes; (2) participant provided information (PPI) Ever Smoking; and, (3) PPI Current Smoking, both from the lifestyle survey. We performed a phenome-wide association study (PheWAS) for each smoking exposure measurement type. For each, we compared the effect sizes derived from the PheWAS to published meta-analyses that studied cigarette smoking from PubMed. We defined two levels of replication of meta-analyses: (1) nominally replicated: which required agreement of direction of effect size, and (2) fully replicated: which required overlap of confidence intervals.

RESULTS

PheWASes with EHR Smoking, PPI Ever Smoking, and PPI Current Smoking revealed 736, 492, and 639 phenome-wide significant associations, respectively. We identified 165 meta-analyses representing 99 distinct phenotypes that could be matched to EHR phenotypes. At P < .05, 74 were nominally replicated and 55 were fully replicated. At P < 2.68 × 10-5 (Bonferroni threshold), 58 were nominally replicated and 40 were fully replicated.

DISCUSSION

Most phenotypes found in published meta-analyses associated with smoking were nominally replicated in All of Us. Both survey and EHR definitions for smoking produced similar results.

CONCLUSION

This study demonstrated the feasibility of studying common exposures using All of Us data.

Age- and sex-stratified detection rates and associated factors of colorectal neoplasia in the Tianjin colorectal cancer screening program from 2012 to 2020

PURPOSE

Colorectal cancer (CRC) screening has been implemented in Tianjin, China since 2012. The objective was to estimate the neoplasia detection rate in a high-risk population by age and sex and to investigate the potential factors associated with colorectal neoplasia.

PATIENTS AND METHODS

This study is based on data of the Tianjin CRC screening program from 2012 to 2020. Residents with a positive high-risk factors questionnaire (HRFQ) or a positive faecal immunochemical test (FIT) were identified as high-risk participants and were subsequently recommended for a free colonoscopy.

RESULTS

A total of 4,117,897 eligible participants aged 40-74 years completed both a HRFQ and FIT, and 217,164 (5.3%) of them were identified as high-risk participants. Positive rates of preliminary screening increased with age and were higher in females than in males. For 57,971 participants undertaking colonoscopy, the detection rates of nonadvanced adenoma, advanced adenoma and CRC were 37.8%, 5.7% and 1.6%, respectively. Detection rates of advanced neoplasia increased from the age of 50 and were higher in males. For nonadvanced neoplasia, a strong increase was observed in males from the age of 40 and in females from the age of 50. Male sex had a greater impact on individuals aged 40-49 than on older individuals. Several factors including current smoking, drinking, and higher body mass index (BMI) were significantly associated with the presence of neoplasia, whereas, these associations were mainly restricted to individuals aged above 50 but not those aged 40-49 years.

CONCLUSIONS

These findings support that age-specific risk stratification and sex-specific initiating ages for CRC screening should be recommended to improve the accuracy and effectiveness of current screening strategy.

Opium use and risk of colorectal cancer: a multi-center case-referent study in Iran

BACKGROUND

Opium use has been associated with an increased risk of cancers of the lung, oesophagus, and pancreas, and it was recently classified by the International Agency for Cancer Research as carcinogenic to humans. It is not clear whether opium also increases the risk of colorectal cancer (CRC). The aim of our study was to assess the association between various metrics of opium use and the risk of CRC.

METHODS

This case-referent study from seven provinces in Iran comprised 848 CRC cases and 3215 referents. Data on opium use (duration, amount, frequency) and potential confounders were collected by trained interviewers. Multivariable unconditional logistic regression models were used to measure odds ratios (OR) adjusted for age, gender, province, marital status, family history of CRC-linked cancers, consumption of red meat, fruits and vegetables, body shape, occupational physical activity, and socioeconomic status.

RESULTS

Regular opium consumption was not associated with the risk of CRC (OR 0.9, 95% confidence interval, CI: 0.7, 1.2) compared to subjects who never used opium. However, frequent opium use more than twice a day was associated with an increased risk of CRC compared to non-users of opium (OR: 2.0, 95% CI: 1.1, 3.8; p for quadratic trend 0.008).

CONCLUSION

There seems to be no overall association between opium use and CRC, but the risk of CRC might be increased among persons who use opium many times a day.

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.

Prevalence of incidental colorectal cancer and polyps in autopsies of different populations: a systematic review with meta-regression analysis

The colorectal cancer (CRC) and polyps incidentally found in autopsies represent the lesions that have not actually caused problems throughout the lifetime and thus may not need to be removed during screening. This study aimed to investigate the prevalence of incidental CRC (iCRC) and polyps in autopsies of different populations. A systematic search was performed on 19 August 2022 to identify autopsy studies that provided data on prevalence of iCRC, adenomatous polyps, hyperplastic polyps, and/or all polyps combined. The prevalence was pooled with the random-effects model. Subgroup and multivariable meta-regression analyses were conducted to investigate the heterogeneity. Forty-three eligible studies including 59,656 autopsies were identified, with 94% conducted before 1990 when CRC screening was uncommon or not available. The pooled prevalence was 0.7% (95% confidence interval [CI], 0.3-1.2%) for iCRC, 18.4% (95% CI, 13.3-24.1%) for adenomatous polyps, 16.4% (95% CI, 8.7-25.9%) for hyperplastic polyps, 26.3% (95% CI, 15.4-38.8%) for all polyps combined, and 29.9% (95% CI, 14.8-47.6%) for iCRC plus polyps. The prevalence of iCRC was higher (1.2%) in white-predominant populations but lower (0.4%) after excluding low-quality studies. Multivariable analyses showed that the prevalence of polyps was higher in white-predominant populations and higher-quality studies, increased with age, and showed a downward trend from "before 1975" through "after 1985". In conclusion, the prevalence of iCRC in autopsies was not low, considering the average lifetime risk of CRC, while incidental polyps were common. Both varied greatly in different populations. These findings may have implications when weighing the benefits and harms of screening.

Smoking and colorectal neoplasia in patients with inflammatory bowel disease: Dose-effect relationship

BACKGROUND AND AIMS

Prior studies on the effect of smoking on the risk of colitis-associated colorectal neoplasia (CRN) have reported conflicting results. We aimed to further elucidate the association between smoking, including possible dose-effects, and the development of colorectal neoplasia in patients with inflammatory bowel disease (IBD).

METHODS

We performed a prospective multicenter cohort study including patients with colonic IBD enrolled in a surveillance program in four academic hospitals between 2011 and 2021. The effects of smoking status and pack-years at study entry on subsequent recurrent events of CRN (including indefinite, low- and high-grade dysplasia, and colorectal cancer [CRC]) were evaluated using uni- and multivariable Prentice, Williams, and Peterson total-time Cox proportional hazard models. Adjustment was performed for extensive disease, prior/index dysplasia, sex, age, first-degree relative with CRC, primary sclerosing cholangitis, and endoscopic inflammation.

RESULTS

In 501 of the enrolled 576 patients, at least one follow-up surveillance was performed after the study index (median follow-up 5 years). CRN occurred at least once in 105 patients. Ever smoking was not associated with recurrent CRN risk (adjusted hazard ratio [aHR] 1.04, 95% confidence interval [CI] 0.75-1.44), but an increasing number of pack-years was associated with an increased risk of recurrent CRN (aHR per 10 pack-years 1.17, 95% CI 1.03-1.32; p < 0.05). Separate analyses per IBD type did not reveal differences.

CONCLUSIONS

This study found that an increase in pack-years is associated with a higher risk of recurrent CRN in patients with IBD, independent of established CRN risk factors (NCT01464151).

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.

Early Onset Metastatic Colorectal Cancer: Current Insights and Clinical Management of a Rising Condition

Despite a recent overall decrease in colorectal cancer (CRC) incidence and mortality, there has been a significant rise in CRC diagnoses in young adults. Early onset colorectal cancer (EOCRC) is defined as CRC diagnosed before the age of 50. Possible predisposing conditions include not only genetic syndromes but also other risk factors, such as microbiome alteration, antibiotic exposure, obesity, diabetes mellitus, and inflammatory bowel disease. EOCRC tends to be diagnosed later than in the older counterpart because of a lack of awareness and the fact that screening for CRC usually starts at the age of 50. Furthermore, CRC in young adults seems to be related to unique molecular features and more aggressive clinical behavior. This paper aims to provide an in-depth review of this poorly understood subject, with a comprehensive review of the state of the art and considerations for future perspectives.

[Relationship of demographic and dietary hygiene factors with the pathology found in outpatient colonoscopies performed in a Castilla y León Health Service center]

Introduction

Background: colorectal cancer (CRC) is one of the most frequent tumors in terms of incidence and mortality. Several elements, both inherited and environmental, have been related with its pathogenesis. Aims: to analyze the influence of age, gender and nutritional factors on the diagnosis of colonic polyps and CRC. Methods: a prospective, descriptive study over outpatients from the Health Area of León who took a colonoscopy between 09/09/2012 and 06/30/2013. Patients were asked to fill a semiquantitative food frecuency questionnaire with data such a sociodemographic, toxic and dietetic facts. Differences in diagnosis according to sociodemographic and hygiene-dietetic data were analyzed with a multivariate analysis by forward stepwise logistic regression. Results: data were collected from 1390 patients. Mean age was 57.88 (15.17) years and 47.8 % were male. CRC was diagnosed in 5 % of colonoscopies, and polyps in 20.4 %, with 9.4 % of them being HRA. Risk of polyps and HRA was higher in males (26.9 % vs 14.5 %) and (12.6 % vs 6.3 %), respectively (p < 0.001). Mean age was significantly higher in patients who presented polyps (56.51 (15.45) vs 63.22 (12.69) years; p < 0.001). Among the group who reported intake of smoked and salted food, the risk of polyps doubled (2.9 % vs 6.7 %, p = 0.002). In relation to alcohol intake we found that subjects with daily alcohol consumption showed a higher incidence of polyps whe compared to occasional drinkers and teetotallers (32 % vs 20 % vs 18.6 %, p = 0.002) Conclusions: age correlated with higher risk of polyps, HRA and CRC. Moreover, male gender also was associated with a high risk of polyps and HRA. Alcohol and red and processed meat intake increased polyp risk.

Modifiable lifestyle factors have a larger contribution to colorectal neoplasms than family history

BACKGROUND

 Screening recommendations for colorectal cancer (CRC) are mainly based on family history rather than lifestyle risk factors. We aimed to assess and compare risk factors for colorectal neoplasm (CRN) and evaluate trends in neoplasm detection rates during the three rounds of screening from 2012 to 2020 in Tianjin, China.

METHODS

This study was based on 89,535 first-recorded colonoscopies in Tianjin CRC screening program, 2012-2020. Of these, 45,380 individuals with complete family history and lifestyle factors were included for population attributable fraction (PAF) estimation.

RESULTS

 The overall detection rate of nonadvanced adenomas, advanced adenomas and CRC was 39.3%, 5.9% and 1.5%, respectively. The PAFs of current smoking, alcohol consumption, physical activity, higher BMI and family history of CRC, respectively, were 8.9%, 2.6%, 1.9%, 5.8%, and 1.1% for males with nonadvanced CRN; 12.3%, 7.3%, 4.9%, 7.2%, and 0.8% for males with advanced CRN; 3.4%, 0.4%, 2.1%, 7.8%, and 0.7% for females with nonadvanced CRN; and 4.3%, 0.2%, 8.2%, 8.5%, and -0.6% for females with advanced CRN. The PAFs of selected lifestyle factors were 19.9% for males with nonadvanced CRN, 29.0% for males with advanced CRN, 9.7% for females with nonadvanced CRN and 13.8% for females with advanced CRN.

CONCLUSIONS

 Modifiable lifestyle factors, including smoking, alcohol consumption, physical activity and BMI, have a larger contribution to CRN than family history of CRC. Our findings will provide references for developing guidelines of CRC prevention and control in China.

Risk Factors for Colorectal Adenocarcinoma in an Indigenous Population in East Africa

Introduction

The incidence of colorectal cancer (CRC) is increasing in East Africa. Changes in lifestyle and dietary changes, particularly alcohol consumption, smoking, and consumption of cooked meats with a reduction in fibre in the diet may be responsible. The objective of our study was to determine the risk factors responsible for CRC in Uganda.

Methods

We recruited 129 participants with histologically proven colorectal adenocarcinoma and 258 control participants from four specialized hospitals in central Uganda from 2019 to 2021. Controls were block matched for age (±5 years) and sex of the case participants. The risk factor variables included; area of residence, tribe, body mass index (BMI), smoking, alcohol consumption and family history of gastrointestinal cancer. We used conditional or ordinal logistic regression to obtain crude and adjusted odds ratios for risk factors associated with CRC.

Results

In bivariate analysis, case participants were more likely to be associated with urban residence (cOR:62.11; p<0.001); family history of GI cancer (cOR: 14.34; p=0.001); past smokers (cOR: 2.10; p=0.080); past alcohol drinkers (cOR: 2.35; p=0.012); current alcohol drinkers (cOR: 3.55; p<0.001); high BMI 25–29.9 kg/m² (cOR: 2.49; p<0.001); and high BMI ≥30kg/m² (cOR: 2.37; p=0.012). In the multivariate analysis, urban residence (aOR: 82.79; p<0.001), family history of GI cancer (aOR: 61.09; p<0.001) and past smoking (aOR: 4.73; p=0.036) were independently associated with a higher risk of developing CRC.

Conclusion

A family history of gastrointestinal cancer was a risk factor for CRC. While population-based CRC screening may not be feasible in low income-countries, targeted CRC screening for first-degree relatives with CRC should be considered in East Africa. Molecular genetic studies need to be carried out to determine the role of hereditary factors in our population. Prevention strategies should be adopted to avoid smoking in our population which was associated with an increased risk of CRC.

Establish a Novel Model for Predicting the Risk of Colorectal Ademomatous Polyps: a Prospective Cohort Study

Purpose: To establish and validate a model to determine the occurrence risk of colorectal ademomatous polyps.

Methods: A large cohort of 3576 eligible participants who were treated in the Department of Gastroenterology, the First Affiliated Hospital of Nanjing Medical University from June 2019 to December 2021, were enrolled in our study and divided into discovery and validation cohorts at a ratio of 7:3. LASSO regression method was applied for data dimensionality reduction and feature selection. The nomogram for the occurrence risk of colorectal ademomatous polyps was constructed based on multivariate logistic regression. The predictive performance of the model was evaluated regarding its discrimination, calibration, and clinical applicability.

Results: A total of 10 high-risk factors were independent predictors of the colorectal ademomatous polyps occurrence and incorporated into the nomogram, including older age, male, hyperlipidemia, smoking, high consumption of red meat, high consumption of salt, high consumption of dietary fiber, Helicobacter pylori infection, non-alcoholic fatty liver disease and chronic diarrhea. The model showed favorable discrimination values, with the area under the curve of the discovery and validation cohorts 0.775 (95% confidence interval (CI), 0.755-0.794) and 0.776 (95% CI, 0.744-0.807) respectively. The model was also well-calibrated, with Hosmer-Lemeshow test P = 0.370. In addition, the decision curve analysis revealed that the model had a higher net profit compared with either the screen-all scheme or the screen-none scheme.

Conclusion: In this prospective study, we established and validated a prediction model that incorporated a list of high-risk features related to colorectal ademomatous polyps occurrence, showing favorable discrimination and calibration values.

Early gastric neoplasms are significant risk factor for colorectal adenoma: A prospective case-control study

Although gastric cancer patients have a high incidence and risk of colorectal cancer, evidence is lacking regarding whether early gastric neoplasms (EGNs), such as gastric adenomas and early gastric cancer, are risk factors for colorectal adenoma. This study aimed to investigate the incidence of colorectal adenomas in patients with EGN. This prospective study was conducted between January 2015 and December 2016. Of the 307 patients who underwent gastric endoscopic submucosal dissection for EGN, 110 patients were enrolled in the EGN group, and 110 age- and sex-matched healthy persons from the screening population were included in the control group in a 1:1 ratio. Demographic factors and results of colonoscopy, including quality assessment, were collected, and analyzed. No significant differences in the quality of colonoscopy, including bowel preparation, cecal intubation rate, and withdrawal time between the 2 groups, were observed. The incidence of colorectal adenoma was significantly higher in the EGN group than in the control group (55.5% vs 26.4%, P = .001). Multivariate analysis confirmed that old age (odds ratio: 1.04, 95% confidence interval: 1.01-1.08, P = .005) and a history of EGN (odds ratio: 4.99, 95% confidence interval: 2.60-9.57, P = .001) were independent risk factors for colorectal adenoma. This is the first prospective study to reflect the quality indicator of colonoscopy and confirmed that old age and a history of EGN are significant risk factors for colorectal adenomas. Therefore, more stringent colonoscopy surveillance should be considered in elderly patients with EGN.

Risk factors and prediction algorithm for advanced neoplasia on screening colonoscopy for average-risk individuals

BACKGROUND

Screening with colonoscopy for all average-risk population is probably not cost-effective due to the limited sources and over-generalization of the risk, and risk stratification can be used to optimize colorectal cancer screening.

OBJECTIVES

We aimed to assess risk factors for advanced neoplasia (AN) and a classification tree algorithm to predict the risk.

DESIGN

This is a retrospective cross-sectional study.

METHODS

This study was composed of consecutive asymptomatic average-risk individuals undergoing first screening colonoscopy between 2008 and 2019. Detailed characteristics including background diseases, habits, and medications were collected. We used multivariable logistic regression to investigate the associations between clinical variables and the presence of AN and built a classification algorithm to predict AN.

RESULTS

A total of 3856 patients were included (73.2% male, median age 55). Adenoma and AN detection rate were 15.8% and 3.4%, respectively. On multivariable analysis, predictors of AN [odds ratio (OR), 95% confidence interval (CI)] were age (1.04, 1.01-1.06, p = 0.003), male sex (2.69, 1.56-4.64, p < 0.001), and smoking (1.97, 1.38-2.81, p  < 0.001). A classification tree algorithm showed that smoking was the most important risk factor for prediction of AN (4.9% versus 2.4%, p < 0.001), followed by age with a cutoff value of 60 in the smokers (8.4% versus 3.8%, p = 0.001) and 50 in the non-smokers (2.9% versus 0.9%, p = 0.004).

CONCLUSION

Smoking habits, old age, and male gender are highly associated with an increased risk for AN and should be incorporated in the individualized risk-assessment to adapt a screening program.

Caracterización del cáncer colorrectal en pacientes atendidos en un centro médico del caribe colombiano

Introducción. A nivel mundial el cáncer colorrectal es la tercera causa de malignidad y la segunda causa de mortalidad por cáncer. En Colombia, tiene una prevalencia de 8,3 % dentro de las patologías neoplásicas, ubicándolo en el tercer lugar, después del cáncer de próstata y de mama, lo que lo cataloga como un problema de salud pública, por lo que es de gran importancia mantener datos actualizados acerca de su perfil epidemiológico. Métodos. Se realizó un estudio transversal en pacientes con cáncer colorrectal atendidos en el Hospital Universitario del Caribe, Cartagena, Colombia, durante el periodo 2015-2019. Se analizaron las variables sociodemográficas, clínicas, patológicas e histológicas. Resultados. Se encontraron un total de 268 pacientes atendidos por cáncer colorrectal, con predominio femenino en el (54,5 %) de los casos, y edad promedio de 62 años; con comorbilidades en 48,8 % y sintomatología de dolor abdominal en 56,7 %. El adenocarcinoma se encontró en el 82,1 % de los casos y la intervención más realizada fue la hemicolectomía derecha. Conclusión. El perfil epidemiológico del cáncer colorrectal encontrado en este estudio concuerda con los hallazgos de la literatura médica mundial, comprometiendo especialmente mujeres en nuestra institución.

Cigarette Smoke Increases Risk for Colorectal Neoplasia in Inflammatory Bowel Disease

BACKGROUND & AIMS

Patients with inflammatory bowel disease are at increased risk of colorectal neoplasia (CRN) due to mucosal inflammation. As current surveillance guidelines form a burden on patients and healthcare costs, stratification of high-risk patients is crucial. Cigarette smoke reduces inflammation in ulcerative colitis (UC) but not Crohn's disease (CD) and forms a known risk factor for CRN in the general population. Due to this divergent association, the effect of smoking on CRN in IBD is unclear and subject of this study.

METHODS

In this retrospective cohort study, 1,386 IBD patients with previous biopsies analyzed and reported in the PALGA register were screened for development of CRN. Clinical factors and cigarette smoke were evaluated. Patients were stratified for guideline-based risk of CRN. Cox-regression modeling was used to estimate the effect of cigarette smoke and its additive effect within the current risk stratification for prediction of CRN.

RESULTS

153 (11.5%) patients developed CRN. Previously described risk factors, i.e. first-degree family member with CRN in CD (p-value=.001), presence of post-inflammatory polyps in UC (p-value=.005), were replicated. Former smoking increased risk of CRN in UC (HR 1.73; 1.05-2.85), whereas passive smoke exposure yielded no effect. For CD, active smoking (2.20; 1.02-4.76) and passive smoke exposure (1.87; 1.09-3.20) significantly increased CRN risk. Addition of smoke exposure to the current risk-stratification model significantly improved model fit for CD.

CONCLUSIONS

This study is the first to describe the important role of cigarette smoke in CRN development in IBD patients. Adding this risk factor improves the current risk stratification for CRN surveillance strategies.

Epidemiology and biology of early onset colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in men or women in the United States. Average-risk screening that begins at age 50 years has reduced incidence and mortality of CRC in those over 50 years of age, whereas CRC incidence in those under age 50 years (early onset colorectal cancer (eoCRC)) has recently and dramatically increased. In this review, we summarize the recent literature including risk factors for eoCRC, differences in clinicopathologic presentation and outcomes in eoCRC, and emerging evidence regarding the molecular pathways that are altered in eoCRC compared to later onset CRC (loCRC). Epidemiologic studies of eoCRC show predominance in distal colon and rectum, and association with several modifiable risk factors, including diabetes, obesity, diet, sedentary time, alcohol consumption and smoking. Data regarding potential risk factors of prior antibiotic exposure and microbiome alterations or direct carcinogen exposure are still emerging. Aggressive clinicopathologic features of eoCRC at presentation may be due to delay in diagnosis or more aggressive tumor biology. EoCRC outcomes are similar to loCRC when matched for stage, but overall mortality is greater due to higher frequency of advanced disease at a younger presentation, with more life-years lost. There are only few molecular evaluations of eoCRC to date, with findings of potential increase in TP53 and CTNNB1 somatic mutation and decrease in APC, KRAS and BRAF somatic mutation, compared to loCRC. Other findings include LINE-1 hypomethylation, absence of microsatellite instability (MSI-H), presence of chromosomal instability (CIN) or microsatellite and chromosomal stability (MACS). These studies are only now emerging and have not yet identified a specific molecular signature defining eoCRC. Further research evaluating genetic and molecular differences as well as environmental triggers for eoCRCs should provide a clearer understanding to inform targeted screening for pre-symptomatic at-risk younger individuals.

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.

Factors associated with positive predictive value of preliminary screening in a two-step screening strategy for colorectal neoplasms in China

BACKGROUND

The positive predictive value (PPV) of high risk factor questionnaire (HRFQ) plus fecal immunochemical test (FIT) as preliminary screening strategy for colorectal-related neoplasia is relatively low. We aim to explore independent factors associated with PPVs of HRFQ combined FIT for selecting high risk individuals for colonoscopy.

METHODS

A total of 6971 residents were enrolled in a community-based screening program. Participants who had positive results of HRFQ and/or FIT and subsequently received colonoscopy were involved. The associations of socio-demographic factors, lifestyle behaviors, and high risk factors of colorectal cancer with PPVs of HRFQ, FIT, and their combination were evaluated by multivariable logistic regression models.

RESULTS

Among 572 involved cases, 249 (43.5%) colorectal neoplasms were detected by colonoscopy, including 71 advanced adenoma (12.4%) and 9 colorectal cancer (CRC) (1.6%). The PPVs of preliminary screening were 43.5% for total colorectal neoplasms, 14.0% for advanced neoplasm, and 1.6% for CRC. Adding positive HRFQ to FIT could improve the PPV from 3.5 to 8.0% for detecting CRC. Preliminarily screened positive individuals who were males [adjusted odds ratio (AOR): 1.95, 95% CI 1.31, 2.90; p  < 0.001], elders (> 60 years) (AOR: 1.70, 95% CI 1.17, 2.46; p  = 0.005), or ex-/current smokers (AOR: 3.04, 95% CI 1.31, 7.09; p  = 0.10) had higher odds of PPVs of detecting colorectal neoplasms.

CONCLUSIONS

Combining HRFQ and FIT could largely improve PPVs for screening advanced neoplasm and CRC. Gender and age-specific FIT cut-off values as well as initiating ages for CRC screening might be recommended to improve the accuracy and effectiveness of current screening algorithm.

Risk Factors for the Diagnosis of Colorectal Cancer

BACKGROUND

Colorectal cancer defined as cancer of the colon or rectum, is the third most frequently diagnosed cancer in men and the second in women, and, according to the World Health Organization database GLOBOCAN, it accounts for nearly 1.4 million new cases annually worldwide. The occurrence of colorectal cancer is associated with nonmodifiable risk factors, including age and hereditary factors, as well as with modifiable environmental and lifestyle factors.

METHODS

The study included 800 patients, 400 diagnosed with colorectal cancer and 400 within the control group, who gave their written informed consent to participate in the study. Patients with cancer other than colorectal cancer were randomly selected for control group I, and patients with no cancer diagnosis were selected for control group II. The method used was a case-control study - an observational and analytical study with a control group, conducted among patients of the Clinical Oncology Centre and the Provincial Hospital in the years 2019-2020. The study comparing the exposure was carried out in a group of people who developed the endpoint, that is colorectal cancer, with the exposure in a well-matched group of controls who did not reach the endpoint. Assessment of activity and BMI was used according to WHO recommendations, as well as the expert system. The data were tested for the distribution and the homogeneity of variance was validated before applying the parameter tests. Comparison of quantitative variables between groups was performed using ANOVA.

RESULTS

The mean age of the patients was 64.53 ± 8.86 years, of the control group I - 59.64 ± 9.33 and the control group II - 57.5 (7.83). There was a strong positive association between the incidence of ulcerative colitis and the risk of colorectal cancer (P < .01). Among obese subjects, the risk of developing colorectal cancer was 1.27 (95% CI, 1.06-1.53) compared with nonobese subjects. A strong positive relationship was found between low physical activity converted to metabolic equivalent of MET effort per week and the risk of colorectal cancer (P < .001). The relative risk for current smokers was 2.17 (95% CI 1.79-2.66). There was an association between higher fat consumption and higher red meat consumption and the risk of developing colorectal cancer (P < .01).

CONCLUSIONS

Obesity, low physical activity, active and passive smoking and high salt and red meat consumption have been associated with an increased risk of colorectal cancer. These findings provide further evidence of the importance of maintaining a healthy lifestyle.

Design and verification of individualized follow-up strategy of colonoscopy for postoperative patients with colorectal cancer

BACKGROUND

Current guidelines do not establish an individual scheme for surveillance colonoscopy in postoperative colorectal cancer (CRC) patients.

AIMS

The purpose of the study was to screen possible risk factors for the development of metachronous adenoma in postoperative CRC patients and to develop a risk prediction model and verify it.

METHODS

Consecutive postoperative patients with CRC were enrolled from April 2007 to December 2013 as the derivation group. Baseline data of patients and clinicopathological features of the tumor were collected, logistic regression analysis was performed, and clinical model was established and was verified internally. The model was externally validated in an independent cohort (validation group) from January 2014 to October 2017 in the same hospital.

RESULTS

A total of 734 patients were included, with average (64.6 ± 11.5) years old. The overall incidence of metachronous adenoma was 35.4%. There was no significant difference in the incidence of metachronous adenoma between the derivation group and validation group (P > 0.05). Age, diabetes mellitus, right colon cancer, moderately to poorly differentiated adenocarcinoma and synchronous adenoma were independent risk factors for metachronous adenoma. The C-index of the metachronous adenoma line chart model was 0.932, and the index decreased by 0.022 after internal verification. The C-index of external validation was 0.910. The Hosmer-Lemeshow test showed that the P value of metachronous adenoma risk prediction model was 0.247.

CONCLUSIONS

Individual surveillance strategies should be designed for postoperative patients with CRC. For high-risk patients, it is appropriate to undergo more than two colonoscopies in 36 months after operation.

Clinicopathological features and risk factors for developing colorectal neoplasia in Hodgkin's lymphoma survivors

BACKGROUND

Hodgkin's lymphoma (HL) survivors treated with abdominal radiotherapy and/or procarbazine have an increased risk of developing colorectal neoplasia.

AIMS

We evaluated the clinicopathological characteristics and risk factors for developing (advanced) neoplasia (AN) in HL survivors.

METHODS

In all, 101 HL survivors (median age 51 years, median age of HL diagnosis 25 years) underwent colonoscopy and 350 neoplasia and 44 AN (classified as advanced adenomas/serrated lesions or colorectal cancer), mostly right-sided, were detected, as published previously. An average-risk asymptomatic cohort who underwent screening colonoscopy were controls (median age 60 years). Clinicopathological characteristics of AN were evaluated in both groups. Mismatch repair (MMR) status was assessed using immunohistochemistry (MLH1/MSH2/MSH6/PMS2). Logistic regression analysis was performed to evaluate the risk factors for AN in HL survivors, including age at HL diagnosis and interval between HL and colonoscopy.

RESULTS

In 101 colonoscopies in HL survivors, AN was primarily classified based on polyp size ≥10 mm, whereas (high-grade)dysplasia was more often seen in AN in controls. An interval between HL diagnosis and colonoscopy >26 years was associated with more AN compared with an interval of <26 years, with an odds ratio for AN of 3.8 (95% confidence interval 1.4-9.1) (p < 0.01). All 39 AN that were assessed were MMR proficient.

CONCLUSIONS

Colorectal neoplasia in HL survivors differ from average-risk controls; classification AN was primarily based on polyp size (≥10 mm) in HL survivors. Longer follow-up between HL diagnosis and colonoscopy was associated with a higher prevalence of AN in HL survivors.

Designing a Predictive Model for Colorectal Neoplasia Diagnosis Based on Clinical and Laboratory Findings in Colonoscopy Candidate Patients

BACKGROUND

Health authorities have expanded two strategies to diminish CRC-related influence: CR screening and improve diagnostic process in symptomatic patients. The aim of the current study is to design a predictive model to identify the most important risk factors that can efficiently predict patients who have high risk of colorectal neoplasia.

METHOD

A cross-sectional study was constructed to include all patients who had positive test for FIT or had one or more risk factors for colorectal cancer based on the guidelines of detecting high-risk groups for colorectal cancer in Iran. Multivariable binary logistic regression model was constructed for prediction of colorectal neoplasia. We used sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratio to check the accuracy. The Hosmer-Lemeshow test, chi-square test, and p value were used to determine the precision of model.

RESULT

Following an AIC stepwise selection model, only nine potential variables, namely gender, watery diarrhea, IBD, abdominal pain, melena, body mass index, depression drug, anti-inflammatory drug, and age, were found to be a predictor of colorectal neoplasia. The best cut-point probability in the final model was 0.27 and results of sensitivity and specificity, based on maximizing these two criteria, were 66% and 62%, respectively.

CONCLUSION

Overall, our model prediction was comparable with other risk prediction models for colorectal cancer. It had a modest discriminatory power to distinguish an individual's neoplasia colorectal risk.

Smoking Behavior and Prognosis After Colorectal Cancer Diagnosis: A Pooled Analysis of 11 Studies

Background

Smoking has been associated with colorectal cancer (CRC) incidence and mortality in previous studies, but current evidence on smoking in association with survival after CRC diagnosis is limited.

Methods

We pooled data from 12 345 patients with stage I-IV CRC from 11 epidemiologic studies in the International Survival Analysis in Colorectal Cancer Consortium. Cox proportional hazards regression models were used to evaluate the associations of prediagnostic smoking behavior with overall, CRC-specific, and non-CRC-specific survival.

Results

Among 12 345 patients with CRC, 4379 (35.5%) died (2515 from CRC) over a median follow-up time of 7.5 years. Smoking was strongly associated with worse survival in stage I-III patients, whereas no association was observed among stage IV patients. Among stage I-III patients, clear dose-response relationships with all survival outcomes were seen for current smokers. For example, current smokers with 40 or more pack-years had statistically significantly worse overall, CRC-specific, and non-CRC-specific survival compared with never smokers (hazard ratio [HR] =1.94, 95% confidence interval [CI] =1.68 to 2.25; HR = 1.41, 95% CI = 1.12 to 1.78; and HR = 2.67, 95% CI = 2.19 to 3.26, respectively). Similar associations with all survival outcomes were observed for former smokers who had quit for less than 10 years, but only a weak association with non-CRC-specific survival was seen among former smokers who had quit for more than 10 years.

Conclusions

This large consortium of CRC patient studies provides compelling evidence that smoking is strongly associated with worse survival of stage I-III CRC patients in a clear dose-response manner. The detrimental effect of smoking was primarily related to noncolorectal cancer events, but current heavy smoking also showed an association with CRC-specific survival.

Comparison of Right Colon Adenoma Miss Rates Between Water Exchange and Carbon Dioxide Insufflation: A Prospective Randomized Controlled Trial

GOALS

To test the hypothesis that water exchange (WE), when compared with carbon dioxide (CO2) insufflation, significantly reduces the right colon adenoma miss rate (rAMR) in a blinded randomized controlled trial with cap-assisted colonoscopy.

BACKGROUND

The unblinded consecutive group observational data showed that WE significantly decreased rAMR. The unblinded data are limited by potential bias.

STUDY

Consecutive patients aged 45 years or more were randomized to undergo insertion with WE or CO2. Withdrawal and polypectomy were performed with CO2 in both groups to the hepatic flexure. The colonoscope was reinserted to the cecum. A second colonoscopist re-examined the right colon. The second colonoscopist was unaware, but made a guess, of the initial insertion method. The number of additional adenomas divided by the total number detected in both examinations equaled rAMR.

RESULTS

Among 262 patients (131/group), demographic variables were similar. The body mass index was significantly higher in the WE group. Compared with CO2, WE significantly decreased rAMR [18.0% (33/183) vs. 34.6% (62/179), P=0.0025] and right colon serrated polyp miss rate [17.4% (27/155) vs. 39.3% (33/84), P=0.002]. Multivariate logistic regression analysis showed that WE was an independent predictor of rAMR (odds ratio, 0.42; 95% confidence interval, 0.21-0.86), and so was ≥2 adenomas in the right colon (odds ratio, 2.35; 95% confidence interval, 1.17-4.76). Whether the second colonoscopist guessed the insertion method correctly or not, and demographic and procedure variables were not associated with rAMR.

CONCLUSIONS

The randomized controlled trial validated unblinded observational data showing that WE significantly decreased rAMR and right colon serrated polyp miss rate (clinical trial registration number: NCT03845933).

Survival Impact of Chronic Obstructive Pulmonary Disease or Acute Exacerbation on Patients with Rectal Adenocarcinoma Undergoing Curative Resection: A Propensity Score-Matched, Nationwide, Population-Based Cohort Study

PURPOSE

The survival effect of current smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) is unclear for patients with rectal adenocarcinoma undergoing curative resection.

METHODS

We recruited patients with clinical stage I-IIIC rectal adenocarcinoma from the Taiwan Cancer Registry Database who had received surgery. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into two groups by using propensity score matching based on COPD status to compare overall survival outcomes: Group 1 (current smokers with COPD) and Group 2 (nonsmokers without COPD).

RESULTS

In the multivariate Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality for Group 1 compared with Group 2 was 1.25 (1.04-1.51). The aHRs (95% cis) of all-cause mortality for frequency of ≥1 hospitalizations for COPDAE or ≥2 hospitalizations within 1 year before diagnosis were 1.17 (1.05-1.51) and 1.48 (1.03-2.41) compared with no COPDAE in patients with rectal adenocarcinoma undergoing curative resection.

CONCLUSION

In patients with rectal adenocarcinoma undergoing curative resection, being a current smoker with COPD (Group 1) was associated with worse survival outcomes than being a nonsmoker without COPD (Group 2). Being hospitalized at least once for COPDAE within 1 year before the diagnosis of rectal adenocarcinoma is an independent risk factor for poor overall survival in these patients, and a higher number of hospitalizations for COPDAE within 1 year before diagnosis was associated with poorer survival.

Inulin as a Delivery Vehicle for Targeting Colon-Specific Cancer

Natural polysaccharides, as well as biopolymers, are now days widely developed for targeting colon cancer using various drug delivery systems. Currently, healing conformations are being explored that can efficiently play a multipurpose role. Owing to the capability of extravagance colonic diseases with the least adverse effects, biopolymers for site specific colon delivery have developed an increased curiosity over the past decades. Inulin (INU) was explored for its probable application as an entrapment material concerning its degradation by enzymes in the colonic microflora and its drug release behavior in a sustained and controlled manner. INU is a polysaccharide and it consists of 2 to 1 linkage having an extensive array of beneficial uses such as a carrier for delivery of therapeutic agents as an indicative/investigative utensil or as a dietary fiber with added well-being aids. In the main, limited research, as well as information, is available on the delivery of therapeutic agents using inulin specifically for colon cancer because of its capability to subsist in the stomach's acidic medium. This exceptional steadiness and robustness properties are exploited in numerous patterns to target drugs securely for the management of colonic cancer, where they effectively act and kills colonic tumor cells easily. In this review article, recent efforts and inulin-based nano-technological approaches for colon cancer targeting are presented and discussed.

Colonoscopy-Related Mortality in a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program

BACKGROUND & AIMS

Many countries have introduced colorectal cancer (CRC) screening programs with fecal immunochemical tests (FITs), and follow-up colonoscopies for individuals with a positive FIT result. In order to make an informed decision to participate, individuals must be informed about the benefits and harms of FIT-based screening and subsequent colonoscopy. Colonoscopy-related fatal complications in FIT-based screening are understudied. We aimed to estimate the colonoscopy-related mortality in a national FIT-based CRC screening program.

METHODS

Colonoscopy-related mortality within 30 days after colonoscopy was assessed by analysis of data from national endoscopy complication databases in the Netherlands, determining the excess 30-day rate of death in FIT-positive individuals undergoing colonoscopy vs FIT-negative individuals (based on data from the national screening database), and determining the rate of likely colonoscopy-related deaths based on registered causes of death by the Statistics Netherlands.

RESULTS

Between October 2013 and December 2017, 172,797 participants underwent colonoscopy after a positive result from a FIT in the Dutch national CRC screening program; 13,848 participants received a diagnosis of CRC. The reported fatal complication rate was 0.23 per 10,000 FIT-positive participants (or 1 per 43,199; 95% CI, 0.090 - 0.60) undergoing colonoscopy, whereas this was 0.91 per 10,000 FIT-positive participants (or 1 per 10,961; 95% CI, 0.44 - 1.38) according to the excess death rate. Likely colonoscopy-related causes of death were reported in 0.86 per 10,000 FIT-positive participants (or 1 per 11,236; 95% CI, 0.48 - 1.63) who underwent colonoscopy, of which 50% considered cardiovascular events.

CONCLUSIONS

Colonoscopy-related mortality within the Dutch FIT-based CRC screening program was estimated to range from 0.23 to 0.91 per 10,000 FIT-positive participants undergoing colonoscopy. These findings indicate underreporting of fatal complications in registries and a noteworthy incidence of fatal cardiovascular adverse events that requires further investigation. Nevertheless, the harm of FIT-based CRC screening is vastly outweighed by the benefits.

The risk of colorectal neoplasm in ex- and never-smokers according to urinary cotinine level

To investigate the relationship between urinary cotinine and colorectal neoplasm (CRN).The participants in the health screening cohort of the National Cancer Center who underwent screening colonoscopy between June 2007 and December 2009 were included. A total of 8121 subjects who underwent urinary cotinine measurement within 14 days from the index colonoscopy were included. Cotinine positivity was defined as having a urinary cotinine level ≥50 ng/mL. Follow-up colonoscopy data were collected by reviewing the patients' medical records.Patients were classified according to their urinary cotinine level and self-reported smoking status, and the number of patients with cotinine positivity was 1960 (24.1%). There was no significant difference in the cumulative CRN and advanced CRN (ACRN) risks according to the self-reported smoking status. However, cotinine positivity at the time of index colonoscopy was an independent risk factor for CRN (hazard ratio [HR]= 1.23, P = .006) in follow-up colonoscopy. Moreover, in never- and ex-smokers, cotinine positivity was an independent risk factor for CRN (HR = 1.95, P = .019; HR = 2.12, P = .003, respectively) and ACRN (HR = 8.89, P < .001; HR = 5.03, P = .003) during follow-up colonoscopy. The cumulative incidence of CRN and ACRN was higher in the cotinine-positive never- and ex-smokers than in the cotinine-negative never- and ex-smokers (P < .001 and P = .008, respectively).CRN or ACRN is more likely to occur at follow-up colonoscopy in the urinary cotinine-positive never- and ex-smokers than in the urinary cotinine-negative group. Therefore, urinary cotinine measurements may provide useful information on never- or ex-smokers undergoing screening colonoscopy.

Why is colorectal cancer increasing in younger age groups in the United States?

Introduction: While colorectal cancer (CRC) incidence and mortality have decreased for older adults, the rates are increasing in adults younger than 50 years of age in the United States as well as globally. In response to strong epidemiologic evidence as well as sophisticated models, the American Cancer Society (ACS) has recommended screening adults for CRC starting at age 45. Understanding the factors associated with the rise of incidence in adults younger than age 50 may help to identify those adults who may be at greatest risk.Areas covered: In this review, we provide an overview of the recent literature and discuss possible explanations for the increase in CRC in young adults including obesity and other recognized CRC risk factors, delay in diagnosis of symptomatic patients (<50 years of age), and review perspectives on the current and future status of the field.Expert opinion: Currently there are little data regarding risk factors for CRC in average risk young adults who are asymptomatic. With potential endorsement of screening at 45 years of age by US Preventive Services Task Force, more data regarding clinical and molecular risk factors associated with CRC in young adults will be available.

Increased Th17-Related Cytokine Serum Levels in Patients With Multiple Polyps of Unexplained Origin

Most patients with multiple colonic polyps do not have a known genetic or hereditary origin. Our aim was to analyze the presence of inflammatory cytokines and levels of glucose, insulin, and C-reactive protein (CRP) in patients with multiple colonic polyps.

Smoking, Genetic Predisposition, and Colorectal Cancer Risk

INTRODUCTION

Smoking and genetic predisposition are established risk factors for colorectal cancer (CRC). We aimed to assess and compare their individual and joint impact on CRC risk using the novel approach of genetic risk equivalent (GRE).

METHODS

Data were extracted from the Darmkrebs: Chancen der Verhütung durch Screening study, a large population-based case-control study in Germany. A polygenic risk score (PRS) based on 140 CRC-related single nucleotide polymorphisms was derived to quantify genetic risk. Multiple logistic regression was used to estimate the individual and joint impact of smoking and PRS on CRC risk, and to quantify the smoking effect in terms of GRE, the corresponding effect conveyed by a defined difference in PRS percentiles.

RESULTS

There were 5,086 patients with CRC and 4,120 controls included. Current smokers had a 48% higher risk of CRC than never smokers (adjusted odds ratio 1.48, 95% confidence interval 1.27-1.72). A PRS above the 90th percentile was significantly associated with a 3.6-, 4.3-, and 6.4-fold increased risk of CRC in never, former, and current smokers, respectively, when compared with a PRS below the 10th percentile in never smokers. The interaction between smoking and PRS on CRC risk did not reach statistical significance (P = 0.53). The effect of smoking was equivalent to the effect of having a 30 percentile higher level of PRS (GRE 30, 95% confidence interval 18-42).

DISCUSSION

Both smoking and the PRS carry essentially independent CRC risk information, and their joint consideration provides powerful risk stratification. Abstinence from smoking can compensate for a substantial proportion of genetically determined CRC risk.

Variation rs9929218 and risk of the colorectal Cancer and adenomas: A meta-analysis

BACKGROUNDS

Genome-wide association studies (GWAS) have identified multiple common CRC-related (colorectal cancer) SNPs (single nucleotide polymorphisms) including the Cadherin 1(CDH1) rs9929218 may act by increasing the risk of colorectal cancer, colorectal adenoma, or both. These studies, however, reported inconsistent associations.

METHODS

To derive a more accurate approximation of the connection, we carried out a meta-analysis of 12 published pieces of research including 11,590 controls and 8192 cases. We used odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the associations' strength.

RESULTS

Meta-analysis implied considerable association between CRC and rs9929218 (OR = 1.21, 95%CI 1.04-1.42 for GG versus AA; OR = 1.22, 95%CI 1.05-1.42 for GG/AG versus AA). In the subgroup analyses, significantly increased risks were found among Europeans.

CONCLUSIONS

In summary, our meta-analysis studies in different populations confirmed that SNP rs9929218 is significantly associated with CRC risk and that this variant may have a greater impact on Europeans.

Smoking and Colorectal Cancer Risk, Overall and by Molecular Subtypes: A Meta-Analysis

INTRODUCTION

The aim of this study was to provide the most comprehensive and up-to-date evidence on the association between cigarette smoking and colorectal cancer (CRC) risk.

METHODS

We conducted a systematic review and meta-analysis of epidemiological studies on the association between cigarette smoking and CRC risk published up to September 2018. We calculated relative risk (RR) of CRC according to smoking status, intensity, duration, pack-years, and time since quitting, with a focus on molecular subtypes of CRC.

RESULTS

The meta-analysis summarizes the evidence from 188 original studies. Compared with never smokers, the pooled RR for CRC was 1.14 (95% confidence interval [CI] 1.10-1.18) for current smokers and 1.17 (95% CI 1.15-1.20) for former smokers. CRC risk increased linearly with smoking intensity and duration. Former smokers who had quit smoking for more than 25 years had significantly decreased risk of CRC compared with current smokers. Smoking was strongly associated with the risk of CRC, characterized by high CpG island methylator phenotype (RR 1.42; 95% CI 1.20-1.67; number of studies [n] = 4), BRAF mutation (RR 1.63; 95% CI 1.23-2.16; n = 4), or high microsatellite instability (RR 1.56; 95% CI 1.32-1.85; n = 8), but not characterized by KRAS (RR 1.04; 95% CI 0.90-1.20; n = 5) or TP53 (RR 1.13; 95% CI 0.99-1.29; n = 5) mutations.

DISCUSSION

Cigarette smoking increases the risk of CRC in a dose-dependent manner with intensity and duration, and quitting smoking reduces CRC risk. Smoking greatly increases the risk of CRC that develops through the microsatellite instability pathway, characterized by microsatellite instability-high, CpG island methylator phenotype positive, and BRAF mutation.

Adenoma Characteristics and the Influence of Alcohol and Cigarette Consumption on the Development of Advanced Colorectal Adenomas

Background: Colorectal cancer (CRC), one of the leading public health problems worldwide, is a disease that can be prevented when it is detected in time. The objectives of this cross-sectional study were to investigate the characteristics of colorectal adenomas and whether alcohol consumption and cigarette smoking correlated with the development of advanced adenomas in participants in The National Programme for Early Detection of Colorectal Cancer (NP) in Osijek-Baranja County (OBC), Croatia. Methods: The screening methods were the guaiac Faecal Occult Blood Test (gFOBT), colonoscopy, histological analysis, and risk factor questionnaire. Results: The results showed the presence of adenomas in 136 men (57.4%) and 101 women (42.6%), p < 0.001. There was one adenoma in 147 (62%) most commonly located in sigmorect, in 86 (59%) participants, and 44 (18.6%) participants had multiple adenomas, most commonly found in multi loc, p < 0.001. According to size, 118 (49.8%) of all adenomas were between 0.1 and 0.9 cm, while adenomas of 3 cm 19 (8%) were the fewest, p < 0.001. There were 142 (59.9%) advanced adenomas. Conclusions: Adenoma development in the OBC population was correlated with predictors: adenoma size, high-grade dysplasia, smoking and alcohol consumption of 20 g per day. Non-smoking was found to be a health protective behaviour.

Colorectal Cancer Genetics, Incidence and Risk Factors: In Search for Targeted Therapies

Each year, colorectal cancers (CRCs) affect over a quarter of a million people. The risk of developing CRC in industrialized nations is approximately 5%. When the disease is localised, treatment success rates range from 70-90%; however, advanced CRC has a high mortality rate, consistently ranking in the top three causes of cancer-related deaths. There is a large geographic difference in global distribution, and CRC is predominantly associated with developed countries and a Western lifestyle and diet. As such, the developed world accounts for more than 63% of all cases of CRC. Geographic variations also predict cancer outcomes, which differ between racial and ethnic groups. This variation is due to inequalities in wealth, differences in the exposure to risk factors and barriers to high-quality cancer prevention, early detection and treatment. The aim of this paper was to review CRC in low- and middle-income countries such as South Africa, India, Brazil and China, and compare them with high-income countries such as the United States of America and the United Kingdom. It is important to note that these economically less developed countries, with historically low CRC rates, are experiencing an increased frequency of CRC. The review also discusses biological markers and genetic pathways involved in the development of colorectal cancer. Genes known to be responsible for the most common forms of inherited CRCs have also been identified but more remain to be identified. This would provide more candidate genes to be added to known biomarkers. CRC burden can be controlled through the widespread application of existing knowledge, such as reduced smoking habits, vaccination, early detection and promoting physical activity, accompanied by a healthy diet. An increased understanding of the molecular mechanisms and events underlying colorectal carcinogenesis will enable the development of new targets and therapeutic drugs.

The DNA Glycosylase NEIL2 Suppresses Fusobacterium-Infection-Induced Inflammation and DNA Damage in Colonic Epithelial Cells

Colorectal cancer (CRC) is the third most prevalent cancer, while the majority (80-85%) of CRCs are sporadic and are microsatellite stable (MSS), and approximately 15-20% of them display microsatellite instability (MSI). Infection and chronic inflammation are known to induce DNA damage in host tissues and can lead to oncogenic transformation of cells, but the role of DNA repair proteins in microbe-associated CRCs remains unknown. Using CRC-associated microbes such as Fusobacterium nucleatum (Fn) in a coculture with murine and human enteroid-derived monolayers (EDMs), here, we show that, among all the key DNA repair proteins, NEIL2, an oxidized base-specific DNA glycosylase, is significantly downregulated after Fn infection. Fn infection of NEIL2-null mouse-derived EDMs showed a significantly higher level of DNA damage, including double-strand breaks and inflammatory cytokines. Several CRC-associated microbes, but not the commensal bacteria, induced the accumulation of DNA damage in EDMs derived from a murine CRC model, and Fn had the most pronounced effect. An analysis of publicly available transcriptomic datasets showed that the downregulation of NEIL2 is often encountered in MSS compared to MSI CRCs. We conclude that the CRC-associated microbe Fn induced the downregulation of NEIL2 and consequent accumulation of DNA damage and played critical roles in the progression of CRCs.

Risk factors including night shift work of colorectal polyp

Background

The destruction of circadian rhythms by night shift work affects major circadian genes, which are known to play a role in advancing or killing the cell cycle through tumor suppressor genes. To find out whether night shift work affects the incidence of colorectal cancer, which was found to be associated with long-term night shift work in previous studies, we surveyed effect of night shift work on colorectal polyps that have a higher incidence than colorectal cancer and can progress to colorectal cancer.

Methods

To examine the correlation between rotating night shifts and colorectal polyps, a survey was conducted with 299 men aged 40–60 years from two university hospitals. We examined lifestyle, work history, work patterns, and colonoscopy results. The differences in prevalence among the groups was compared, and prevalence ratio (PR) was calculated via generalized linear modeling.

Results

The prevalence of colorectal polyps in night shift and non-shift workers were 53.0% and 33.5%, respectively. After adjusting for age, smoking status, dietary habits, family history of colorectal cancer, obesity, job type, night shift work (PR: 1.13, 95% CI: 1.02–1.25) was a risk factor of colorectal polyps.

Conclusions

The risk of colorectal polyps was greater in night shift workers than non-shift workers. Also risk of colorectal polyp was higher in older group. Our study investigated colorectal polyp instead of colorectal cancer and lacks information about types and gene mutations of colorectal polyps. Further study is needed to clarify effect of night shift work on development of colorectal cancer.

Prevalence and risk factors for colorectal polyps in a Chinese population: a retrospective study

The incidence of colorectal polyps is rising. Certain types of polyps are considered to be the precursor lesions for colorectal cancers. To investigate the prevalence and related factors of colorectal polyps in Chinese subjects, we first performed a cross-sectional study. A total of 3066 subjects were documented, and the prevalence of colorectal polyps was 18.1%. Then we evaluated the incidence and risk factors of polyps via a retrospective cohort study in the same population. 561 subjects who received at least twice surveillance colonoscopies with available reports during the study period and had no polyp at the first endoscopy were included in the retrospective cohort study, of whom 19.1% developed colorectal polyps. Regular smoking was independently associated with the presence and development of colorectal polyps. Further analyses indicated that polyps were associated with smoking status, daily cigarette consumption, and drinking habit. Moreover, smoking tends to be more relavent to rectal, small and single polyp. In conclusion, colorectal polyp is a common disease in China. Exploring the epidemiology and risk factors may improve the prevention of colorectal polyps, even colorectal cancer.

Colorectal Polyp Prevalence According to Alcohol Consumption, Smoking and Obesity

This study aimed to analyze colorectal polyp prevalence associated with health behavior. Data from 1180 Korean men (young adult (YA), aged 40-49; middle age (MA) aged 50-59; old aged (OA), aged 60-79 years) were collected. Health behavior included alcohol consumption, smoking status, and obesity. Obesity was determined using body mass index (BMI) and waist circumference (WC). Odds ratio (OR) was calculated by logistic regression. The prevalence of polyps increased for current smokers by 2.642 times in the YA group, 3.468 times in the MA group, and 3.104 times in the OA group compared to the never-smokers. The OR for WC increased in subjects with obesity by 1.514 in the MA and 1.451 in the OA group compared to normal. The prevalence of three or more polyps increased with WC obesity by 2.3 times in YA, 2.2 times in MA, and 1.9 times in OA compared to normal WC. Therefore, smoking cessation and obesity management may reduce the risk of colorectal polyps.

Epidemiology and Mechanisms of the Increasing Incidence of Colon and Rectal Cancers in Young Adults

In contrast to the decreasing incidence of colorectal cancer (CRC) in older populations, the incidence has nearly doubled in younger adults since the early 1990s. Approximately 1 in 10 new diagnoses of CRC are now made in individuals 50 years or younger. Patients' risk of CRC has been calculated largely by age and family history, yet 3 of 4 patients with early-onset CRC have no family history of the disease. Rapidly increasing incidence rates in younger people could result from generational differences in diet, environmental exposures, and lifestyle factors. We review epidemiologic trends in CRC, data on genetic and nongenetic risk factors, and new approaches for determining CRC risk. These may identify individuals likely to benefit from early screening and specialized surveillance.

Effect of Cotinine-Verified Change in Smoking Status on Risk of Metachronous Colorectal Neoplasia After Polypectomy

BACKGROUND & AIMS

Previous assessments of colorectal neoplasia (CRN) recurrence after polypectomy used self-report to determine smoking status. We evaluated the association between change in smoking status and metachronous CRN risk after polypectomy using cotinine level in urine to determine tobacco exposure.

METHODS

We performed a retrospective study of participants in the Kangbuk Samsung Health Study in Korea who underwent a screening colonoscopy examination and measurement of cotinine in urine samples. Our analysis included 4762 patients who had 1 or more adenomas detected in an index colonoscopy performed between January 2010 and December 2014, and underwent a surveillance colonoscopy, 6 or more months later, until December 2017.

RESULTS

Patients were classified into 4 groups based on the change in cotinine-verified smoking status from index to follow-up colonoscopy (mean interval, 3.2 ± 1.3 y), as follows: remained nonsmokers (n = 2962; group 1), smokers changed to nonsmokers (n = 600; group 2), nonsmokers changed to smokers (n = 138; group 3), and remained smokers (n = 1062; group 4). After adjustment for confounding factors, group 4 had a significantly higher risk of metachronous CRN than group 1 (hazard ratio [HR], 1.54; 95% CI, 1.36-1.73) and group 2 (HR, 1.63; 95% CI, 1.39-1.99). Group 4 also had a higher risk of metachronous advanced CRN than group 1 (HR, 2.84; 95% CI, 1.79-4.53) and group 2 (HR, 2.10; 95% CI, 1.13-3.89). Group 3 had a higher risk of metachronous CRN than group 1 (HR, 1.50; 95% CI, 1.14-1.97) and group 2 (HR, 1.62; 95% CI, 1.20-2.20).

CONCLUSIONS

In a retrospective study of individuals with at least 1 adenoma, we found that cotinine-verified changes in smoking status between index and follow-up colonoscopy are associated with a risk of metachronous CRN. Helping patients quit smoking is important for effective prevention of colorectal cancer.

Colorectal carcinoma screening: Established methods and emerging technology

Colorectal carcinoma screening programs have shown success in lowering both the incidence and mortality rate of colorectal carcinoma at a population level, in part because this carcinoma is relatively slow growing and has an identifiable premalignant lesion. Still, many patients do not undergo the recommended screening for colorectal carcinoma, and of those who do, a subset may be over- or under-diagnosed by the currently available testing methods. The primary purpose of this article is to review the data regarding currently available colorectal cancer screening modalities, which include fecal occult blood testing, direct colonic visualization, and noninvasive imaging techniques. In addition, readers will be introduced to a variety of biomarkers that may serve as stand-alone or adjunct tests in the future. Finally, there is a brief discussion of the current epidemiologic considerations that public health officials must address as they create population screening guidelines. The data we provide as laboratory physicians and scientists are critical to the construction of appropriate recommendations that ultimately decrease the burden of disease from colorectal carcinoma.

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.

Lifestyle and dietary environmental factors in colorectal cancer susceptibility

Colorectal cancer (CRC) incidence changes with time and by variations in diet and lifestyle, as evidenced historically by migrant studies and recently by extensive epidemiologic evidence. The worldwide heterogeneity in CRC incidence is strongly suggestive of etiological involvement of environmental exposures, particularly lifestyle and diet. It is established that physical inactivity, obesity and some dietary factors (red/processed meats, alcohol) are positively associated with CRC, while healthy lifestyle habits show inverse associations. Mechanistic evidence shows that lifestyle and dietary components that contribute to energy excess are linked with increased CRC via metabolic dysfunction, inflammation, oxidative stress, bacterial dysbiosis and breakdown of gut barrier integrity while the reverse is apparent for components associated with decreased risk. This chapter will review the available evidence on lifestyle and dietary factors in CRC etiology and their underlying mechanisms in CRC development. This short review will also touch upon available information on potential gene-environment interactions, molecular sub-types of CRC and anatomical sub-sites within the colorectum.