Risk Of Advanced Colorectal Neoplasia Research Articles

Association between Diverticulosis and Colorectal Neoplasia: Analysis from a Large Austrian Database.

Background: Colorectal neoplasia and diverticulosis are common findings on colonoscopies. While adenomas are precursors to colorectal cancer, diverticulosis is usually asymptomatic but can lead to diverticulitis. Despite their prevalence and coexistence, the relationship between these conditions remains unclear. This study investigates whether diverticulosis is associated with adenomas, considering shared risk factors and potential inflammation-driven mechanisms. Methods: We examined 6154 asymptomatic individuals undergoing colorectal cancer screening in Austria. Diverticulosis and colorectal neoplasia were documented during screenings based on macroscopic definitions. Advanced neoplasia was defined as polyps >1 cm or high-grade dysplasia. Associations between diverticulosis and neoplastic findings were assessed using univariate and multivariable logistic regression models. Results: Although the overall incidence of any polypoid lesion was higher in the diverticulosis group (37% vs. 30%), statistical analysis revealed a comparable rate of advanced neoplasms in both groups. Importantly, no significant link between diverticulosis and advanced neoplasms was found (OR 1.125; 95% CI: 0.933 to 1.357, p = 0.218) even after adjusting for confounding factors. In a univariate analysis, a statistically significant association between diverticulosis and the presence of any colorectal polyps was identified (OR 1.388; 95% CI: 1.244-1.549, p < 0.0001). However, after adjusting for confounding factors in model 2 (OR 1.065, 95% CI: 0.942 to 1.204, p = 0.314) and model 3 (OR 1.071, 95% CI: 0.925 to 1.239, p = 0.360), this effect was also not statistically significant. Conclusions: Patients with diverticulosis share demographic and clinical features with those at risk of colorectal neoplasia, such as older age, male gender, and higher cardiometabolic risk. However, diverticulosis does not independently increase the risk of advanced colorectal neoplasia or unspecified polypoid lesions.

Performance of the Asia-Pacific Colorectal Screening score in stratifying the risk of advanced colorectal neoplasia: A meta-analysis and systematic review.

This study systematically reviewed and meta-analyzed the performance of the Asia-Pacific Colorectal Screening (APCS) score and its incorporation with the fecal immunochemical test (FIT) in stratifying the risk of advanced colorectal neoplasia (ACN). We systematically searched for relevant articles in 12 electronic databases and registers on October 20, 2021, and updated the search to September 1, 2023. Random-effect models were used to obtain the pooled performance statistics of the APCS score for ACN risk. From the 101 records screened, 13 eligible studies in the Asia-Pacific region involving 69762 subjects who had undergone colonoscopy were enrolled. The pooled prevalences of ACN in the average-risk (AR) tier (APCS 0-1), moderate-risk (MR) tier (APCS 2-3), and high-risk (HR) tier (APCS≥4) groups were 0.9%, 3.1%, and 8.1%, respectively. Compared with the combined AR-MR group, the HR group was significantly associated with a higher ACN risk (pooled diagnostic odds ratio: 2.84, 95% confidence interval [CI]: 2.35-3.45, P<0.001). The APCS score showed a sensitivity of 0.42 (95% CI: 0.40-0.44) and a specificity of 0.86 (95% CI: 0.85-0.86) for predicting the ACN risk, with a weighted area under the curve of 0.642 (95% CI: 0.610-0.657). The combination of the APCS score and FIT substantially improved ACN risk identification, demonstrating pooled diagnostic odds ratios of 4.02 (95% CI: 2.50-6.49) in the AR-MR groups and 5.44 (95% CI: 1.89-15.63) in the MR-HR groups. The APCS score could effectively stratify the ACN risk in the Asia-Pacific population. Incorporating FIT further improves its performance in identifying high-risk subjects who should be prioritized for colonoscopy screenings.

The Association of Metabolic Risk Factors with Advanced Adenomas in Hispanic Patients.

Obesity and metabolic syndrome (MetS) have been implicated as rising risk factors for the development of colorectal cancers. A rapid increase in the prevalence of obesity and severe obesity among Hispanic patients in the United States may present substantially increased risk for advanced colorectal neoplasia in this population. Currently, there is very little research in this area. We sought to identify metabolic risk factors for advanced adenomas (AA) in Hispanic Americans. We retrospectively reviewed data from the Los Angeles General (LAG) Medical Center of asymptomatic Hispanic patients above 45 years of age who underwent their first colonoscopies following a positive screening FBT. Patient demographics, metabolic characteristics, as well as colon polyp size and histology were recorded. Polyps were classified as adenomas or AA (including both high-risk adenomas and high-risk serrated polyps). Relative risk for AA was assessed by multivariate logistical regression analyses. Of the 672 patients in our study, 41.4% were male, 67% had adenomas, and 16% had AA. The mean BMI was 31.2kg/m2. The mean HDL-C was 49.5mg/dL (1.28 mmol/L) and the mean triglyceride level was 151mg/dL. 44.6% had diabetes and 64.1% had hypertension. When comparing patients with AA to patients with no adenoma, male sex, BMI > 34.9kg/m2, and elevated fasting triglyceride levels were associated with an increased risk of AA. FIB-4 ≥1.45 was also associated with an increased risk of AA in males. There was no significant difference in the risk of AA with diabetes, hypertension, FIB-4 score, LDL-C level, and HDL-C level. Hispanic patients with a positive FBT were observed to have a high incidence of AA. Class II obesity (BMI ≥ 35kg/m2), elevated triglyceride levels were identified as risk factors among males in our study. Early interventions to address these modifiable risk factors in at-risk populations, such as multi-disciplinary weight management programs for the treatment of obesity and related co-morbidities, could potentially lead to risk reduction and CRC prevention.

Fecal Immunochemical Testing and the Risk of Advanced Colorectal Neoplasia: A Difference-In-Difference Analysis.

To evaluate the effectiveness of fecal immunochemical testing (FIT) in colorectal cancer screening. We conducted a prospective cohort study among 5,598 participants age 40-74 years between 2012 and 2020 in Tianjin, China. Inverse probability weighting was adopted to adjust for potential imbalanced factors between groups. A Cox proportional hazards model was used to estimate the weighted associations between FIT screening and advanced colorectal neoplasia. A difference-in-difference (DID) model was adopted to compare the incidence rates of advanced colorectal neoplasia between groups. In DID analysis, the rate of incidence was reduced by 0.34 cases per person-years in the screening group as compared with the historical FIT screening group (rate ratio [RR], 0.08 [95% CI, 0.07 to 0.10]) and by 0.06 cases per person-years in the non-FIT screening group as compared with the historical non-FIT screening group (RR, 0.37 [95% CI, 0.29 to 0.48]; P < .001 for both comparisons), with a relative reduction of 0.28. Similar benefit effect from FIT screening was observed in sex and age subgroups. FIT screening was associated with a reduction in incidence density from advanced colorectal neoplasia.

Appendectomy and Risk of Advanced Colorectal Neoplasia in Inflammatory Bowel Disease: A Nationwide Population-based Cohort Study.

The aim of this study was to examine the association between appendectomy and advanced colorectal neoplasia (aCRN) in patients with inflammatory bowel disease (IBD). Inflammatory bowel disease patients diagnosed in Denmark in the period 1977 to 2017 were identified from the Danish National Patient Registry. Inflammatory bowel disease patients who underwent appendectomy were matched with up to 10 IBD patients without appendectomy and followed until aCRN, death, or emigration. Absolute risks of aCRN were calculated, treating death and bowel resections as competing risks. Stratified Cox regression was used to calculate adjusted hazard ratios (aHRs) of aCRN, comparing IBD patients with appendectomy to IBD patients without appendectomy. We identified 3789 IBD patients with appendectomy and 37 676 IBD patients without appendectomy. A total of 573 patients (1.4%) developed aCRN, with an absolute risk of aCRN at 20 years of 4.9% (95% confidence interval [CI], 2.9%-7.7%) for ulcerative colitis (UC) patients with appendectomy after UC diagnosis compared with 2.8% (95% CI, 2.3%-3.3%) for UC patients without appendectomy. Appendectomy after UC was associated with an increased rate of aCRN 5 to 10 years (aHR, 2.5; 95% CI, 1.1-5.5) and 10 to 20 years after appendectomy (aHR, 2.3; 95% CI, 1.0-5.5). Appendectomy prior to UC diagnosis was not associated with an increased rate of aCRN, and Crohn's disease was not associated with the rate of aCRN, regardless of timing or histological diagnosis of the appendix specimen. Although appendectomy may have a positive effect on the clinical course of UC, our study suggests that this may come at the expense of a higher risk of aCRN.

Prediction of advanced colorectal neoplasia based on metabolic parameters among symptomatic patients.

Worldwide, colorectal cancer (CRC) is the third most common cancer and ranks second among the leading causes of cancer death. This study aims to devise and validate a scoring system based on metabolic parameters to predict the risk of advanced colorectal neoplasia (ACN) in a large Chinese population. This was a cohort study of 495584 symptomatic subjects aged 40years or older who have received colonoscopy in Hong Kong from 1997 to 2017. The algorithm's discriminatory ability was evaluated as the area under the curve (AUC) of the mathematically constructed receiver operating characteristic curve. Age, male gender, inpatient setting, abnormal aspartate transaminase/alanine transaminase, white blood cell, plasma gamma-glutamyl transferase, high-density lipoprotein cholesterol, triglycerides, and hemoglobin A1c were significantly associated with ACN. A scoring of <2.65 was designated as "low risk (LR)." Scores at 2.65 or above had prevalence higher than the overall prevalence and hence were assigned as "high risk (HR)." The prevalence of ACN was 32% and 11%, respectively, for HR and LR groups. The AUC for the risk score in the derivation and validation cohort was 70.12%. This study has validated a simple, accurate, and easy-to-use scoring algorithm, which has a high discriminatory capability to predict ACN in symptomatic patients. Future studies should examine its predictive performance in other population groups.

The causal association between sarcopenia and colorectal cancer: a Mendelian Randomization analysis.

See the reply "Prevalence and associated risk of advanced colorectal neoplasia in adults with sarcopenia" in volume 37 on page 294.

Prevalence and associated risk of advanced colorectal neoplasia in adults with sarcopenia.

Background/AimsAlthough several studies have shown that sarcopenia is associated with poor outcomes in colorectal cancer patients, the impact of sarcopenia on the development of colorectal neoplasia remains unclear. We aimed to evaluate the prevalence and association of colorectal neoplasia, especially advanced colorectal neoplasia, in adults with sarcopenia.MethodsWe retrospectively analyzed the data for 10,676 adults who underwent first-time colonoscopy and bioelectrical impedance analysis (BIA) on the same day in a health screening program at a single center. Sarcopenia was diagnosed using established BIA-based criteria as adjusted appendicular skeletal muscle mass (ASM) divided by body mass index (BMI) (ASM/BMI), height (ASM/height2), or weight (ASM/weight). Prevalence of overall and advanced colorectal neoplasia and their association with sarcopenia, as established by the aforementioned diagnostic criteria, were evaluated.ResultsAmong 10,676 subjects, 583 were diagnosed with sarcopenia using ASM/BMI. Subjects with sarcopenia had a higher prevalence of colorectal neoplasia than those without. In the multivariate analysis after adjusting for confounding factors, sarcopenia was an independent risk factor for any colorectal neoplasia (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.09 to 1.56) and advanced colorectal neoplasia (OR, 1.97; 95% CI, 1.27 to 3.06). The association between sarcopenia and advanced colorectal neoplasia remained significant for all sarcopenia measures including ASM/height2 (OR, 2.19; 95% CI, 1.24 to 3.85) and ASM/weight (OR, 2.41; 95% CI, 1.54 to 3.77).ConclusionsPrevalence of overall and advanced colorectal neoplasia was higher in subjects with sarcopenia than in those without. Sarcopenia was a significant risk factor for colorectal neoplasia, especially for advanced colorectal neoplasia.

Correlation between incidental focal colorectal FDG uptake on PET/CT and colonoscopic and histopathological results

Objective and aims The primary aim of this study was to evaluate the correlation between incidental focal colorectal foci on fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) with colonoscopic and histopathological results. The secondary aim was to determine to what extent these findings led to a change in patient management. Materials and methods A retrospective study was performed among 5850 patients who had an FDG-PT/CT scan from July 2015 to July 2018. Among these patients, we identified patients with a PET/CT description of incidental colorectal FDG uptake, and a colonoscopy within 90 days from the PET/CT scan. PET/CT findings were compared with colonoscopy-detected lesions and eventually histopathology on a per-lesion analysis and a per-person analysis. Results A total of 145 patients were included in the study. A total of 180 foci of colorectal FDG uptake were detected on FDG-PET/CT. Of these, 86 foci corresponded to advanced colorectal neoplasia (ACRN), positive predictive value (PPV) 47.8%; 95% CI: 40.5–55.1%). On a per-patient analysis 81 patients had a least one ACRN at colonoscopy (PPV 55.9%; 95% CI: 47.6–63.8), this group included 20 patients (13.8%) diagnosed with cancer. There was a small positive correlation between focal FDG-uptake and the finding of ACRN at the same colonic segment at colonoscopy, which was statistically significant, rho = 0.2565, p = .002. The findings changed patient management in 67 (46.2%) cases. Conclusions Incidental focal colorectal FDG uptake on PET/CT is associated with a high risk of ACRN and is affecting subsequent patient management. Further evaluation with colonoscopy is recommended when the patient is considered suitable for further treatment.

Risk for Colorectal Cancer in Patients with Serially Positive Fecal Immunochemistry Test in an Annual Screening Program.

Objectives: There are patients who do not undergo colonoscopy even if the fecal immunochemistry test (FIT) results are positive and even with repeated positive test results the following year. We aimed to investigate colorectal cancer (CRC) risk in examinees with positive FIT results in our annual screening program. Methods: We analyzed patients who underwent initial colonoscopy from April 2010 to March 2017 because of positive FIT results using an endoscopy database in our hospital. We investigated the difference in the risk of advanced colorectal neoplasia as a surrogate marker of CRC between those who had an initial positive test and those who had repeated positive tests. Results: A total of 748 patients were included in this analysis. The advanced neoplasia detection rates were 7.6% (50/656) and 18.5% (17/92) for the initial and repeated positive test groups, respectively. Subgroup analysis of those with repeated positive tests revealed that the detection rates in examinees with positive tests 1-2 and >2 years ago were 16.7% (6/36) and 19.6% (11/56), respectively. The odds ratios for advanced neoplasia detection in patients with positive tests 1-2 and >2 years ago compared with those in the initial positive test group were 2.72 (95% confidence interval [CI], 1.04-7.10) and 3.09 (95% CI, 1.47-6.48), respectively. Conclusions: The risk of CRC appears more than doubled in patients with a repeated positive FIT result. Prompt colonoscopy is recommended for FIT-positive cases.

Gender disparities in colorectal polyps

Objective. The main objective of the research is the pathohistological consequences of colorectal adenomatosis polyps and their gender-based assessment. Gender and its connection with advanced colorectal displasia are the focus of the research study.&#x0D; Materials and methods. A retrospective analysis was conducted 100 patients. The age group of the patients in the research study mainly encompassed 19 to 65 aged patients. During the medical procedure, the gender distribution of the cases was determined as 60 males and 40 females respectively.&#x0D; Results. There is strong evidence for an association between gender and the risk of advanced colorectal neoplasia. The findings regarding the positive interrelation for gender and advanced colorectal neoplasia are consistent with other large colonoscopy-based studies.&#x0D; Conclusions. As a result of the study, we would like to emphasize that colorectal polyps are more common in men compared to in women

Comparison of Risk of Metachronous Advanced Colorectal Neoplasia in Patients with Sporadic Adenomas Aged < 50 Versus ≥ 50 years: A Systematic Review and Meta-Analysis.

No specific recommendations are available for the surveillance of young patients aged <50 years undergoing polypectomy. We aimed to compare the risk of metachronous advanced colorectal neoplasia (ACRN) between patients aged ≥50 years and those aged <50 years who underwent polypectomy. Studies published between January 1980 and June 2020 that examined the risk of metachronous ACRN were searched. We performed a meta-analysis for the metachronous ACRN risk in patients with sporadic colorectal adenomas according to the age groups (≥50 vs. <50 years). Eight individual studies were included in the meta-analysis. The risk of metachronous ACRN was higher in patients aged ≥50 years than in those aged <50 years without significant heterogeneity (odds ratio (OR) (95% CI): 1.62 (1.34–1.96), I2 = 14%). The impact of the age group on the risk of metachronous ACRN was identified in both the low-risk (LRA) and high-risk (HRA) adenoma groups (≥50 vs. <50 years: LRA, OR 1.88 (95% CI 1.30–2.70); HRA, OR 1.50 [95% CI 1.13–2.00]). In conclusion, patients aged <50 years had a lower risk of metachronous ACRN than older patients. Young patients with sporadic adenomas do not require more intensive surveillance; rather, the surveillance interval may be extended in these patients.

Deep Neural Network-Based Prediction of the Risk of Advanced Colorectal Neoplasia.

Background/AimsRisk prediction models using a deep neural network (DNN) have not been reported to predict the risk of advanced colorectal neoplasia (ACRN). The aim of this study was to compare DNN models with simple clinical score models to predict the risk of ACRN in colorectal cancer screening.MethodsDatabases of screening colonoscopy from Kangbuk Samsung Hospital (n=121,794) and Kyung Hee University Hospital at Gangdong (n=3,728) were used to develop DNN-based prediction models. Two DNN models, the Asian-Pacific Colorectal Screening (APCS) model and the Korean Colorectal Screening (KCS) model, were developed and compared with two simple score models using logistic regression methods to predict the risk of ACRN. The areas under the receiver operating characteristic curves (AUCs) of the models were compared in internal and external validation databases.ResultsIn the internal validation set, the AUCs of DNN model 1 and the APCS score model were 0.713 and 0.662 (p<0.001), respectively, and the AUCs of DNN model 2 and the KCS score model were 0.730 and 0.667 (p<0.001), respectively. However, in the external validation set, the prediction performances were not significantly different between the two DNN models and the corresponding APCS and KCS score models (both p>0.1).ConclusionsSimple score models for the risk prediction of ACRN are as useful as DNN-based models when input variables are limited. However, further studies on this issue are warranted to predict the risk of ACRN in colorectal cancer screening because DNN-based models are currently under improvement.

Application of deep learning to predict advanced neoplasia using big clinical data in colorectal cancer screening of asymptomatic adults.

Background/AimsWe aimed to develop a deep learning model for the prediction of the risk of advanced colorectal neoplasia (ACRN) in asymptomatic adults, based on which colorectal cancer screening could be customized.MethodsWe collected data on 26 clinical and laboratory parameters, including age, sex, smoking status, body mass index, complete blood count, blood chemistry, and tumor marker, from 70,336 first-time colonoscopy screening recipients. For reference, we used a logistic regression (LR) model with nine variables manually selected from the 26 variables. A deep neural network (DNN) model was developed using all 26 variables. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity of the models were compared in a randomly split validation group.ResultsIn comparison with the LR model (AUC, 0.724; 95% confidence interval [CI], 0.684 to 0.765), the DNN model (AUC, 0.760; 95% CI, 0.724 to 0.795) demonstrated significantly improved performance with respect to the prediction of ACRN (p < 0.001). At a sensitivity of 90%, the specificity significantly increased with the application of the DNN model (41.0%) in comparison with the LR model (26.5%) (p < 0.001), indicating that the colonoscopy workload required to detect the same number of ACRNs could be reduced by 20%.ConclusionsThe application of DNN to big clinical data could significantly improve the prediction of ACRNs in comparison with the LR model, potentially realizing further customization by utilizing large quantities and various types of biomedical information.

Derivation and validation of a predictive model for advanced colorectal neoplasia in asymptomatic adults

ObjectiveKnowing risk for advanced colorectal neoplasia (AN) could help patients and providers choose among screening tests, improving screening efficiency and uptake. We created a risk prediction model for AN to...

Optimization of the surveillance strategy in patients with colorectal adenomas: A combination of clinical parameters and index colonoscopy findings.

In addition to index colonoscopy findings, demographic parameters including age are associated with the risk of metachronous advanced colorectal neoplasia. Here, we aimed to develop a risk scoring model for predicting advanced colorectal neoplasia (ACRN) during surveillance using a combination of clinical factors and index colonoscopy findings. Patients who underwent the removal of one or more adenomas and surveillance colonoscopy were included. A risk scoring model for ACRN was developed using the Cox proportional hazard model. Surveillance interval was determined as a time point exceeding 4% of the cumulative ACRN incidence in each risk group. Of 9591 participants, 4725 and 4866 were randomly allocated to the derivation and validation cohorts, respectively. Age, abdominal obesity, advanced adenoma, and ≥3 adenomas at index colonoscopy were identified as risk factors for metachronous ACRN. Based on the regression coefficients, point scores were assigned as follows: age, 1 point (per 1year); abdominal obesity, 10 points; advanced adenoma, 10 points; and ≥3 adenomas, 15 points. Patients were classified into high-risk (≥80 points), moderate-risk (50-79 points), and low-risk (30-49 points) groups. In the validation cohort, the high-risk and moderate-risk groups showed a higher risk of ACRN than the low-risk group (hazard ratio [95% confidence interval]: 7.11 [4.10-12.32] and 1.58 [1.09-2.30], respectively). Two-, 4-, and 5-year surveillance intervals were recommended for the high-risk, moderate-risk, and low-risk groups, respectively. Our proposed model may facilitate effective risk stratification of ACRN during surveillance and the determination of appropriate surveillance intervals.

Effects of 5-aminosalicylates or thiopurines on the progression of low-grade dysplasia in patients with inflammatory bowel disease: a systematic review and meta-analysis.

Although 5-aminosalicylates and thiopurines may have an antineoplastic effect on colorectal neoplasia in patients with inflammatory bowel disease (IBD), their impact on the progression of low-grade dysplasia (LGD) in IBD is uncertain. Therefore, we performed a systematic review and meta-analysis to evaluate whether 5-aminosalicylates or thiopurines can protect against the progression of LGD in patients with IBD. Systematic searches of PubMed, EMBASE, Cochrane Library databases, and major conference proceedings were conducted to identify all eligible studies through March 2020. Data were pooled using a random effects model. Study quality was assessed using the Newcastle-Ottawa Scale. Five studies comprising 776 IBD patients with LGD were included. Overall, 5-aminosalicylates (Hazard ratio (HR) = 0.91, 95% confidence interval (CI) 0.55-1.51) and thiopurines (HR = 0.64, 95% CI 0.23-1.79) did not significantly reduce the risk of advanced colorectal neoplasia (high-grade dysplasia/cancer) in IBD patients with LGD. Moreover, the effects of 5-aminosalicylates or thiopurines on risk of advanced colorectal neoplasia in IBD patients with LGD were not significant by different primary sclerosing cholangitis status, study quality, sample size, and IBD type. In this study, we did not find a significant protective effect of 5-aminosalicylates or thiopurines on the progression of LGD in patients with IBD.

Association of Cardiovascular Risk Assessment with Early Colorectal Neoplasia Detection in Asymptomatic Population: A Systematic Review and Meta-Analysis.

Previous studies have shown a strong coexistence of colorectal neoplasia (CRN) and cardiovascular diseases (CVD). This study was aimed to summarize the available evidence on association of CVD risk with early CRN detection in asymptomatic populations. PubMed, Web of Science, and Embase were systematically searched for eligible studies published until Dec 20, 2019. Studies exploring the associations of recommended CVD risk assessment methods (e.g., risk scores, carotid artery plaque, and coronary artery calcium score [CACS]) with risk of CRN were included. Meta-analyses were conducted to determine the overall association of CVD risk with the CRN. A total of 12 studies were finally included. The association of carotid artery plaque with the risk of colorectal adenoma (AD) was weakest (pooled odds ratio [OR)] 1.27, 95% confidence interval [CI), 1.12, 1.45]. Participants with CACS>100 had about 2-fold increased risk of AD than those with CACS=0. The pooled ORs were 3.36 (95% CI, 2.15, 5.27) and 2.30 (95% CI, 1.69, 3.13) for the risk of advanced colorectal neoplasia (AN) and AD, respectively, in participants with Framingham risk score (FRS)>20%, when compared to participants at low risk (FRS<10%). FRS might help identify subgroups at increased risk for AN, but further studies are needed.

Issue Highlights

Issue Highlights

Changes in Abdominal Obesity Affect the Risk of Metachronous Advanced Colorectal Neoplasia Development after Polypectomy.

PurposeThe impact of changes in body mass index and waist circumference on the development of metachronous colorectal neoplasia (CRN) after polypectomy has rarely been examined. We evaluated the association between changes in overall/abdominal obesity and metachronous CRN risk.Materials and MethodsWe studied patients who underwent ≥1 adenoma removal and surveillance colonoscopy. Patients were classified into the following four groups based on the changes in overall obesity from index to follow-up colonoscopy: non-obesity persisted (group 1), obesity to non-obesity (group 2), non-obesity to obesity (group 3), and obesity persisted (group 4). Patients were also divided into another four groups based on similar changes in abdominal obesity (groups 5–8).ResultsThe number of patients in groups 1, 2, 3, and 4 was 5074, 457, 643, and 3538, respectively, and that in groups 5, 6, 7, and 8 was 4229, 538, 656, and 2189, respectively. Group 4 had a significantly higher risk of metachronous CRN compared to groups 1 and 2. However, metachronous advanced CRN (ACRN) risk was not different among groups 1, 2, 3, and 4. Metachronous CRN risk in group 8 (abdominal obesity persisted) was higher than that in groups 5 (non-abdominal obesity persisted) and 7 (non-abdominal obesity to abdominal obesity), and tended to be higher than that in group 6 (abdominal obesity to non-abdominal obesity). Additionally, group 8 had a significantly higher risk of metachronous ACRN compared to groups 5, 6, and 7.ConclusionChanges in obesity affected the metachronous CRN risk. In particular, changes in abdominal obesity affected the metachronous ACRN risk.