Occurrence Of Colorectal Adenomas Research Articles

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.

Aspirin and nonaspirin nonsteroidal antiinflammatory drug use and occurrence of colorectal adenoma in Black American women.

Evidence suggests that aspirin use reduces the occurrence of colorectal neoplasia. Few studies have investigated the association among Black Americans, who are disproportionately burdened by the disease. We assessed aspirin use in relation to colorectal adenoma among Black women. The Black Women's Health Study is a prospective cohort of self-identified Black American women established in 1995. Participants reported regular aspirin use on baseline and follow-up questionnaires. Beginning in 1999, participants reported undergoing a colonoscopy or sigmoidoscopy, the only procedures through which colorectal adenomas can be diagnosed. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for associations between aspirin use and colorectal adenoma among 34 397 women who reported at least 1 colonoscopy or sigmoidoscopy. From 1997 through 2018, 1913 women were diagnosed with an adenoma. Compared to nonaspirin users, regular users had 14% (OR = 0.86, 95% CI: 0.78-0.95) lower odds of adenoma. The odds of adenoma decreased with increasing duration of aspirin use (≥10 years: OR = 0.80, 95% CI: 0.66-0.96). Initiating aspirin at a younger age was associated with a reduced adenoma occurrence (age < 40 years at initiation: OR = 0.69, 95% CI: 0.55-0.86). Regular aspirin use was associated with a decreased odds of colorectal adenoma in our study of Black women. These findings support evidence demonstrating a chemopreventive impact of aspirin on colorectal neoplasia and suggest that aspirin may be a useful prevention strategy among US Black women.

Association of Antibody Responses to Fusobacterium nucleatum and Streptococcus gallolyticus Proteins with Colorectal Adenoma and Colorectal Cancer

BackgroundStreptococcus gallolyticus subspecies gallolyticus (SGG) and Fusobacterium (F.) nucleatum have been implicated in colorectal carcinogenesis. Here, the association of immune responses to bacterial exposure with advancing stages of colorectal neoplasia was assessed by multiplex serology.MethodsImmunoglobulin (Ig) A and G antibody responses to eleven proteins each of F. nucleatum and SGG were measured in plasma of controls (n = 100) and patients with colorectal cancer (CRC, n = 25), advanced adenoma (n = 82), or small polyps (n = 85). Multivariable logistic regression was used to evaluate the association of bacterial sero-positivity with colorectal neoplasia. In a cohort subset with matched data (n = 45), F. nucleatum sero-positivity was correlated with bacterial abundance in both neoplastic and matched normal tissue.ResultsIgG sero-positivity to Fn1426 of F. nucleatum was associated with an increased CRC risk (OR = 4.84; 95% CI 1.46–16.0), while IgA sero-positivity to any SGG protein or specifically Gallo0272 and Gallo1675 alone was associated with increased advanced adenoma occurrence (OR = 2.02, 95% CI 1.10–3.71; OR = 2.67, 95% CI 1.10–6.46; and OR = 6.17, 95% CI 1.61–23.5, respectively). Only F. nucleatum abundance in the normal mucosa positively correlated with the IgA response to the Fn1426 antigen (Correlation coefficient (r) = 0.38, p < 0.01).ConclusionAntibody responses to SGG and F. nucleatum were associated with occurrence of colorectal adenomas and CRC, respectively. Further studies are needed to clarify the role these microbes or the immune response to their antigens may have in colorectal carcinogenesis stages.Graphical

Analysis of the relationship between the gut microbiota enterotypes and colorectal adenoma.

The essence of enterotypes is to stratify the entire human gut microbiota, and dysregulation of gut microbiota is closely related to the development of colorectal adenoma. Enterotypes may therefore be a useful target for the prevention of colorectal adenoma. However, the relationship between gut microbiota and colorectal adenoma has not been fully elucidated. In this study, we aimed to analyze the differences in gut microbiome composition between adenoma and control populations. We recruited 31 patients with colorectal adenoma and 71 non-adenoma controls. Patient demographics, risk factors, fecal samples from each subject were collected and metagenomic sequencing was performed. LEfSe analysis was used to reveal differences in intestinal microbiome composition. Multiple logistic regression analysis was used to determine the association between enterotypes and colorectal adenoma. The results showed that Prevotella enterotype (enterotype 4) is only present in adenoma group. Logistic regression analysis showed that Prevotella enterotype was an independent risk factor for colorectal adenoma. The Prevotella enterotype may increase the occurrence of colorectal adenoma through inflammatory association and interference with glucose and lipid metabolism in human body. In conclusion, the differences we observed between different enterotypes add a new potential factor to the development of colorectal adenoma.

The Effect of Low Doses of Acetylsalicylic Acid on the Occurrence of Rectal Aberrant Crypt Foci.

Background and Objectives: Aberrant crypt foci (ACF) are one of the earliest putative preneoplastic and, in some cases, neoplastic lesions in human colons. Many studies have confirmed the reduction of ACFs and colorectal adenomas after treatment with acetylsalicylic acid (ASA) commonly referred to as ASA; however, the minimum effective dose of ASA and the duration of use has not been fully elucidated. The objective of our study was to assess the significance of low dose ASA (75-mg internally once daily) to study the chemopreventive effect of ASA in ACF and adenomas development in patients taking this drug for a minimum period of 10 years. Materials and&amp;nbsp;Methods: Colonoscopy, combined with rectal mucosa staining with 0.25% methylene blue, was performed on 131 patients. The number of rectal ACF in the colon was divided into three groups: ACF &lt; 5; ACF 5-10; and ACF &gt; 10. Patients were divided into two groups: the "With ASA" group (the study group subjects taking ASA 75-mg daily for 10 years); and "Without ASA" group (control group subjects not taking ASA chronically). The incidence of different types of rectal ACF and colorectal polyps in both groups of subjects was analysed and ascertained. Results: Normal ACF was found in 12.3% in the study group vs. 87.7% control group, hyperplastic 22.4% vs. 77.6%, dysplastic 25% vs. 75%, mixed 0% vs. 100%. Treatment with ASA affects the occurrence of colorectal adenomas. The amount of dysplastic ACFs was lower in the study group than in the control group. The increase in dysplastic ACFs decreases with age in both groups, with the increase greater in those not taking ASA. Conclusions: Patients who take persistent, chronic (&gt;10 years) low doses of ASA have a lower total number of all types of rectal ACFs and adenomas compared to the control group.

A two-phase approach to re-calibrating expensive computer simulation for sex-specific colorectal neoplasia development modeling

BackgroundMedical evidence from more recent observational studies may significantly alter our understanding of disease incidence and progression, and would require recalibration of existing computational and predictive disease models. However, it is often challenging to perform recalibration when there are a large number of model parameters to be estimated. Moreover, comparing the fitting performances of candidate parameter designs can be difficult due to significant variation in simulated outcomes under limited computational budget and long runtime, even for one simulation replication.MethodsWe developed a two-phase recalibration procedure. As a proof-of-the-concept study, we verified the procedure in the context of sex-specific colorectal neoplasia development. We considered two individual-based state-transition stochastic simulation models, estimating model parameters that govern colorectal adenoma occurrence and its growth through three preclinical states: non-advanced precancerous polyp, advanced precancerous polyp, and cancerous polyp. For the calibration, we used a weighted-sum-squared error between three prevalence values reported in the literature and the corresponding simulation outcomes. In phase 1 of the calibration procedure, we first extracted the baseline parameter design from relevant studies on the same model. We then performed sampling-based searches within a proper range around the baseline design to identify the initial set of good candidate designs. In phase 2, we performed local search (e.g., the Nelder-Mead algorithm), starting from the candidate designs identified at the end of phase 1. Further, we investigated the efficiency of exploring dimensions of the parameter space sequentially based on our prior knowledge of the system dynamics.ResultsThe efficiency of our two-phase re-calibration procedure was first investigated with CMOST, a relatively inexpensive computational model. It was then further verified with the V/NCS model, which is much more expensive. Overall, our two-phase procedure showed a better goodness-of-fit than the straightforward employment of the Nelder-Mead algorithm, when only a limited number of simulation replications were allowed. In addition, in phase 2, performing local search along parameter space dimensions sequentially was more efficient than performing the search over all dimensions concurrently.ConclusionThe proposed two-phase re-calibration procedure is efficient at estimating parameters of computationally expensive stochastic dynamic disease models.

Plasma Metabolomics Analysis of Aspirin Treatment and Risk of Colorectal Adenomas.

This research used metabolomics, an innovative discovery-based approach, to identify molecular changes in human blood that may help to explain how aspirin use reduces the risk of colorectal neoplasia in some individuals. Ultimately, this work could have important implications for optimizing aspirin use in the prevention of colorectal cancer.

Association of body fat distribution and metabolic syndrome with the occurrence of colorectal adenoma: A case-control study.

Visceral fat is thought to play different roles in the carcinogenesis of the colon with peripheral fat. Our aim was to evaluate the association of body fat distribution measured by bioelectrical impedance analysis (BIA) with the incidence of colorectal adenoma (CRA). A total of 410 asymptomatic participants who underwent a screening colonoscopy from July 2017 to December 2019 in our center were recruited, including 230 with adenomas and 180 without detected adenomas. The participants' body fat was measured by BIA, including their body fat mass (BFM), body fat percentage (BFP), and waist-to-hip ratio. Parameters of metabolic syndrome (MetS), including waist circumference, blood pressure, fasting blood glucose (FBG), blood level of triglyceride, cholesterol, and high-density lipoprotein were measured as well. According to univariate analysis, age, male sex, body mass index, waist circumference, BFM, waist-to-hip ratio, blood pressure, and FBG were higher in the adenoma group than in the adenoma-free group (P < 0.05). On multivariate logistical analysis (adjusted for age, sex, smoking, drinking, and family history of CRC), a high waist-to-hip ratio was associated with a high incidence of CRA (odds ratio [OR] 1.84, 95% confidence interval [CI] 1.09-3.09, P = 0.02). Only a large waist circumference in components of MetS was independently associated with the incidence of CRA (OR 1.90, 95% CI 1.17-3.08, P = 0.01) in the multivariate analysis. Body fat distribution is associated with CRA, central obesity is a core risk factor for CRA in MetS. Chinese Clinical Trial Registration number: ChiCTR-RRC-17010862.

Presence of Metabolic Syndrome and Thyroid Nodules in Subjects with Colorectal Polyps.

BackgroundThyroid nodules (TNs) and metabolic syndrome (MS) have been individually associated with colorectal polyps. However, the potential joint relationship between them in relation to colorectal polyps has not been fully evaluated. This study aimed to validate the association of TNs/MS and colorectal polyps/adenomas and to determine the risk of colonic polyps in patients with TNs/MS.Material/MethodsA retrospective study was conducted on patients undergoing routine health checks in the First Affiliated Hospital of Wenzhou Medical University from July 2014 to August 2017. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for colorectal polyps/adenomas after adjusting for confounding factors. Then patients were divided into 4 groups according to whether they had TNs or MS. Relative excess risks of interaction, attributable proportion, and synergy index were used to determine the additive interaction of TNs and MS on colorectal polyps/adenomas.ResultsA total of 4514 eligible patients were included in this study. TNs and MS were confirmed to be independent risk factors for colorectal polyps/adenomas. Compared with the group of TNs(−)/MS(−), the odds ratios of TNs(+)/MS(+) in colorectal polyps (odds ratio [OR]: 3.031, 95% confidence interval [CI]: 2.262–4.062, P<0.05) or adenomas (OR: 2.894, 95% CI: 2.099–3.990, P<0.05) were significantly increased, and there was an interactive additive effect between TNs and MS.ConclusionsTNs and MS have an associative and superimposing effect on the increased occurrence of colorectal adenomas. Colonoscopy screening should be advocated for patients with both of these diseases.

Metabolically Healthy Obesity Is Associated with an Increased Risk of Colorectal Adenoma Occurrence Diagnosed by Surveillance Colonoscopy.

Background/AimsThe risk of recurrence of colorectal adenoma among obese individuals without metabolic abnormalities or in those with metabolically healthy obesity is largely unexplored. Therefore, we longitudinally investigated the risk of adenoma occurrence in individuals undergoing surveillance colonoscopy according to metabolic status and obesity.MethodsThis retrospective cohort study included 16,872 Korean adults who underwent their first screening colonoscopy between 2003 and 2012 and who then underwent follow-up colonoscopy until 2017. Participants were categorized into a metabolically healthy nonobese group (reference group), a metabolically healthy obese group, a metabolically abnormal nonobese group, and a metabolically abnormal obese group. Hazard ratios (HRs) for adenoma recurrence compared to the reference group were calculated in each group.ResultsDuring a median follow-up duration of 47.3 months (interquartile range, 35.6 to 58.9 months), 3,673 (21.8%) and 292 (1.73%) participants developed adenoma and advanced adenoma, respectively. When age, sex, smoking, alcohol consumption, family history of colorectal cancer, and baseline adenoma risk were adjusted, the risk of adenoma recurrence was increased in metabolically healthy obese individuals (HR, 1.33; 95% confidence interval [CI], 1.12 to 1.57) and metabolically abnormal obese individuals (HR, 1.18; 95% CI, 1.08 to 1.30) but not in metabolically abnormal nonobese individuals (HR, 1.03; 95% CI, 0.94 to 1.13).ConclusionsIn this study, metabolically healthy obese individuals and metabolically abnormal obese individuals exhibited increased risks of occurrence of colorectal adenoma diagnosed by surveillance colonoscopy. This finding implies that obesity itself, even without metabolic abnormalities, is associated with an increased risk of adenoma recurrence. (Gut Liver 2021;15-390)

Detection of Colorectal Carcinoma Based on Microbiota Analysis Using Generalized Regression Neural Networks and Nonlinear Feature Selection.

To obtain a screening tool for colorectal cancer (CRC) based on gut microbiota, we seek here to identify an optimal classifier for CRC detection as well as a novel nonlinear feature selection method for determining the most discriminative microbial species. In this study, the intestinal microflora in feces of 141 patients were modeled using general regression neural networks (GRNNs) combined with the proposed feature selection method. The proposed model led to slightly higher accuracy (AUC = 0.911) than previous studies . The results show that the Clostridium scindens and Bifidobacterium angulatum are indicators of healthy gut flora and CRC happens to reduce these bacterial species. In addition, Fusobacterium gonidiaformans was found to be closely correlated with the CRC. The occurrence of colorectal adenoma was not sufficiently discriminatory based on fecal microbiota implicating that the change of colonic flora happens in the advanced phase of CRC development rather than initial adenoma. Integrating the proposed model with fecal occult blood test (FOBT), the CRC detection accuracy remained nearly unchanged (AUC = 0.915). The performance of the proposed method is validated using independent cohorts from America and Austria. Our results suggest that the proposed feature selection method combined with GRNN is potentially an accurate method for CRC detection.

Visceral obesity as a risk factor for colorectal adenoma occurrence in surveillance colonoscopy

The aim of this study was to examine the prospective association between visceral obesity and the incidence and recurrence of colorectal adenoma. We conducted a cohort study involving 2244 participants between 2006 and 2007. The study participants were prospectively followed until 2014 according to the initial colonoscopy and histopathology findings. Incident and recurrent colorectal adenoma groups were defined as individuals with a positive follow-up colonoscopy result from the normal results and adenoma groups, respectively, at the baseline colonoscopy. Among the 1163 patients (51.8%) who received a follow-up colonoscopy, 509 (43.8%) and 654 (56.2%) were grouped into the normal and adenoma cohorts. Colorectal adenomas occurred in 592 patients (50.9%) during the median period of 43 months, with an incident adenoma prevalence of 39.1% and a recurrent adenoma prevalence of 60.1%. An increase in the visceral adipose tissue (VAT) area was associated with a higher incidence of adenoma (highest quintile vs lowest quintile of the VAT hazard ratios [HRs], 2.16; 95% confidence interval [CI], 1.26-3.71; HR 1.32 [per 1-standard deviation]; 95% CI, 1.10-1.60) in the multivariable analysis. Increases in body mass index and waist circumference were associated with recurrent adenomas (HR 1.33 [per 1 kg/m2], 95% CI, 1.18-1.46; HR 1.04 [per 1 cm], 95% CI, 1.01-1.07, respectively) in the multivariate analysis. A higher VAT area was dose-dependently associated with a higher risk of incident adenoma. Furthermore, increases in body mass index and waist circumference as surrogate markers of abdominal obesity were associated with a higher risk of recurrent adenoma.

Visceral Adipose Tissue Volume and the Occurrence of Colorectal Adenoma in Follow-up Colonoscopy for Screening and Surveillance

ABSTRACTWhether obesity accelerates adenoma recurrence is not yet clear; therefore, we analyzed the risk factors for adenoma occurrence at follow-up colonoscopy, with a focus on visceral adiposity. In total, 1516 subjects underwent index colonoscopy, computed tomography, and questionnaire assessment from February to May 2008; 539 subjects underwent follow-up colonoscopy at the National Cancer Center at least 6 mo after the index colonoscopy. The relationships between the presence of adenoma at follow-up colonoscopy and anthropometric obesity measurements, including body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT) volume, and subcutaneous adipose tissue (SAT) volume, were analyzed. 188 (34.9%) had adenomatous polyps at follow-up colonoscopy. Multivariate analysis revealed that VAT volume ≥ 1000 cm3 and BMI ≥ 30 kg/m2 were related to the presence of adenoma at follow-up colonoscopy (VAT volume 1000–1500 cm3: odds ratio [OR] = 2.13(95% confidence interval, CI = 1.06–4.26), P = 0.034; VAT volume ≥ 1000 cm3: OR = 2.24(95% CI = 1.03–4.88), P = 0.043; BMI ≥ 30 kg/m2: OR = 4.22(95% CI = 1.12–15.93), P = 0.034). In contrast, BMI 25–29.9 kg/m2, SAT volume, and WC were not associated with the presence of adenoma at follow-up colonoscopy. In conclusion, excess VAT can contribute to the development and growth of new colorectal adenomas, and is a better predictor of colorectal adenoma occurrence at follow-up colonoscopy than BMI, WC, and SAT volume.

Plasma lipoxin A4 and resolvin D1 are not associated with reduced adenoma risk in a randomized trial of aspirin to prevent colon adenomas.

Inflammation plays a major role in colon carcinogenesis. Endogenously produced specialized proresolving lipid mediators (SPMs) play a central role in inflammation and tissue homeostasis, and have been implicated in carcinogenesis. We studied the associations of plasma levels of two SPMs [lipoxin A4 (LXA4 ) and resolvin D1(RvD1)] with risk for recurrent adenoma. In this pilot study, we used data and biosamples from an adenoma chemoprevention study investigating the effects of aspirin and/or folic acid on the occurrence of colorectal adenomas. In the parent study, 1121 participants with a recent adenoma were randomized to study agents to be taken until the next surveillance colonoscopy about 3 years later. In this pilot study, LXA4 and RvD1 from samples taken near the end of study treatment were measured in a randomly selected sub-set of 200 participants. Commercially available ELISA kits to assay the analytes were validated using a metabololipidomic LC-MS/MS assay. Poisson regression with a robust error variance was used to calculate risk ratios and 95% confidence intervals. Plasma LXA4 and RvD1 were not associated with the risk of adenoma occurrence. LXA4 at the end of study follow-up was 32% (P = 0.01) proportionately higher in women compared to men. A similar non-significant trend toward higher levels among women was observed for RvD1. Our preliminary findings provided no evidence that plasma LXA4 or RvD1 are associated with reduced risk of colorectal adenoma occurrence, but suggest LXA4 may differ among men and women. Future studies focusing on SPM's local effects and levels in the colon are needed.

Rotating night shift work, sleep, and colorectal adenoma in women.

This study aims to investigate the associations of rotating night shift work history and sleep duration with risk of colorectal adenoma. We evaluated 56,275 cancer-free participants of the Nurses' Health Study II, who had their first colonoscopy or sigmoidoscopy between 1991 and 2011; rotating night shift work and sleep duration were reported by mailed questionnaire. Multivariable-adjusted logistic regression was used to estimate relative risks (RR) of colorectal adenoma, with 95% confidence intervals (CI), across categories of rotating night shift work history (none, 1-4, 5-9, and ≥10years) and sleep duration (≤5, 6, 7, 8, and ≥9h/day). We found no association between duration of rotating night shift work and occurrence of colorectal adenoma (p-trend across shift work categories=0.5). Women with the longest durations of rotating night shift work (≥10years) had a similar risk of adenoma compared to women without a history of rotating night shift work (multivariable-adjusted RR=0.96, 95% CI=0.83-1.11). Similarly, there were no associations of shorter or longer sleep durations with adenoma risk (p-trend=0.2 across sleep durations of ≤5 through 7h/day and p-trend=0.5 across sleep durations of 7 through ≥9h/day). Results were similar when we examined associations according to adenoma location and subtype. Our results do not support an association between rotating night shift work or sleep duration and risk of colorectal adenoma in women.

Colorectal Adenomas in Participants of the SELECT Randomized Trial of Selenium and Vitamin E for Prostate Cancer Prevention.

Selenium and vitamin E micronutrients have been advocated for the prevention of colorectal cancer. Colorectal adenoma occurrence was used as a surrogate for colorectal cancer in an ancillary study to the Selenium and Vitamin E Cancer Prevention Trial (SELECT) for prostate cancer prevention. The primary objective was to measure the effect of selenium (as selenomethionine) on colorectal adenomas occurrence, with the effect of vitamin E (as α-tocopherol) supplementation on colorectal adenoma occurrence considered as a secondary objective. Participants who underwent lower endoscopy while in SELECT were identified from a subgroup of the 35,533 men randomized in the trial. Adenoma occurrence was ascertained from the endoscopy and pathology reports for these procedures. Relative Risk (RR) estimates and 95% confidence intervals (CI) of adenoma occurrence were generated comparing those randomized to selenium versus placebo and to vitamin E versus placebo based on the full factorial design. Evaluable endoscopy information was obtained for 6,546 participants, of whom 2,286 had 1+ adenomas. Apart from 21 flexible sigmoidoscopies, all the procedures yielding adenomas were colonoscopies. Adenomas occurred in 34.2% and 35.7%, respectively, of participants whose intervention included or did not include selenium. Compared with placebo, the RR for adenoma occurrence in participants randomized to selenium was 0.96 (95% CI, 0.90-1.02; P = 0.194). Vitamin E did not affect adenoma occurrence compared with placebo (RR = 1.03; 95% CI, 0.96-1.10; P = 0.38). Neither selenium nor vitamin E supplementation can be recommended for colorectal adenoma prevention. Cancer Prev Res; 10(1); 45-54. ©2016 AACR.

Parameters of Glucose and Lipid Metabolism Affect the Occurrence of Colorectal Adenomas Detected by Surveillance Colonoscopies.

PurposeLimited data are available regarding the associations between parameters of glucose and lipid metabolism and the occurrence of metachronous adenomas. We investigated whether these parameters affect the occurrence of adenomas detected on surveillance colonoscopy.Materials and MethodsThis longitudinal study was performed on 5289 subjects who underwent follow-up colonoscopy between 2012 and 2013 among 62171 asymptomatic subjects who underwent an initial colonoscopy for a health check-up between 2010 and 2011. The risk of adenoma occurrence was assessed using Cox proportional hazards modeling.ResultsThe mean interval between the initial and follow-up colonoscopy was 2.2±0.6 years. The occurrence of adenomas detected by the follow-up colonoscopy increased linearly with the increasing quartiles of fasting glucose, hemoglobin A1c (HbA1c), insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and triglycerides measured at the initial colonoscopy. These associations persisted after adjusting for confounding factors. The adjusted hazard ratios for adenoma occurrence comparing the fourth with the first quartiles of fasting glucose, HbA1c, insulin, HOMA-IR, and triglycerides were 1.50 [95% confidence interval (CI), 1.26–1.77; ptrend<0.001], 1.22 (95% CI, 1.04–1.43; ptrend=0.024), 1.22 (95% CI, 1.02–1.46; ptrend=0.046), 1.36 (95% CI, 1.14–1.63; ptrend=0.004), and 1.19 (95% CI, 0.99–1.42; ptrend=0.041), respectively. In addition, increasing quartiles of low-density lipoprotein-cholesterol and apolipoprotein B were associated with an increasing occurrence of adenomas.ConclusionThe levels of parameters of glucose and lipid metabolism were significantly associated with the occurrence of adenomas detected on surveillance colonoscopy. Improving the parameters of glucose and lipid metabolism through lifestyle changes or medications may be helpful in preventing metachronous adenomas.

Metformin therapy and the risk of colorectal adenoma in patients with type 2 diabetes: A meta-analysis.

BackgroundExisting data evaluating the impact of metformin on the colorectal adenoma (CRA) risk in patients suffering from type 2 diabetes (T2D) are limited and controversial. We therefore summarized the studies currently available and assessed the relationship between metformin treatment and risk of CRA in T2D patients.MethodsWe systematically searched databases for eligible studies that explored the impact of metformin treatment on the occurrence of CRA in T2D patients from inception to June 2016. The summary odds ratio (OR) estimates with their 95% confidence interval (CI) were derived using random-effect, generic inverse variance methods. Sensitivity analysis and subgroup analysis were performed.ResultsSeven studies involving 7178 participants met the inclusion criteria. The pooling showed that metformin therapy has a 27% decrease in the CRA risk (OR, 0.73; 95% CI, 0.58 - 0.90). In subgroup analysis, we detected that metformin exhibits significant chemoprevention effects in Asia region (OR, 0.68; 95% CI, 0.48 - 0.96). Similar results were identified in both studies with adjusted ORs and high-quality studies (OR, 0.66; 95% CI, 0.50 - 0.86 and OR, 0.70; 95% CI, 0.58 - 0.84, respectively). Of note, an inverse relationship was noted that metformin therapy may result in a significant decrease in the advanced adenoma risk (OR, 0.52; 95% CI, 0.38 - 0.72). Low heterogeneity was observed, however, the results remained robust in multiplesensitivity analyses.ConclusionsThis meta-analysis indicates that metformin therapy is correlated with a significant decrease in the risk of CRA and advanced adenoma in T2D patients. Further confirmatory studies are warranted.

People with low serum folate levels have higher risk of colorectal adenoma/advanced colorectal adenoma occurrence and recurrence in China.

ObjectiveTo investigate the potential association between serum folate levels and colorectal adenoma (CRA) occurrence and recurrence.MethodsThis prospective study measured baseline serum folate levels in outpatients who were screened for CRA using colonoscopy. Participants were then randomly selected to produce one group with CRA and one without CRA. These two subgroups underwent further follow-up observations of colonoscopy to determine the occurrence of new and recurrent CRA.ResultsA total of 1310 participants were screened at baseline: 888 were healthy subjects without CRA; and 422 had CRA. Two subgroups were randomly selected (n = 200 per group) for follow-up. In the overall population, baseline serum folate levels were significantly lower in patients with CRA or advanced CRA (A-CRA) compared with healthy participants without CRA. Similar findings were shown for the follow-up study in terms of the association between CRA and A-CRA occurrence and recurrence and baseline serum folate levels. After controlling for confounders, increased serum folate was associated with a reduced risk of occurrence of CRA (odds ratio [OR] 0.993, 95% confidence interval [CI] 0.924, 1.066) and recurrence of CRA (OR 0.749, 95% CI 0.322, 1.742).ConclusionsHigher serum folate levels may be protective against CRA and/or A-CRA.

C-reactive protein and risk of colorectal adenomas or serrated polyps: a prospective study.

Serum C-reactive protein (CRP) is a sensitive marker of systemic inflammation. Because there is a well-recognized relationship between local inflammation and colorectal cancer, we aimed to evaluate whether serum CRP levels were associated with the occurrence of colorectal adenomas and serrated polyps using data from a large adenoma prevention trial. A total of 930 participants with a history of colorectal adenomas were enrolled in a randomized trial of calcium supplementation (1,200 mg/day) for the prevention of colorectal adenomas. Outcomes in this analysis are metachronous adenomas (and advanced neoplasms specifically), and serrated polyps at follow-up colonoscopy. High-sensitivity CRP levels were measured 1 year following baseline colonoscopy. Multivariate analysis was performed to estimate risk ratios (RR) using Poisson regression, controlling for potential confounders. We measured serum CRP levels in 689 participants (mean CRP, 3.62 ± 5.72 mg/L). There was no difference in CRP levels with respect to calcium versus placebo treatment assignment (P = 0.99). After adjustment for potential confounders, we found no association between CRP level and risk of recurrent adenoma or advanced lesion [quartile 4 vs. quartile 1: RR, 95% confidence interval (CI) = 0.99 (0.73-1.34) and 0.92 (0.49-1.75), respectively]. Similarly, no association was seen between CRP levels and risk of serrated polyps or proximal serrated polyps [quartile 4 vs. quartile 1: RR (95% CI) = 1.32 (0.85-2.03) and 1.19 (0.54-2.58), respectively]. In conclusion, this large prospective colorectal adenoma chemoprevention study found no significant relationship between CRP levels and occurrence of adenomas, advanced neoplasms, or serrated polyps.