Abdominal visceral adipose tissue predicts risk of colorectal adenoma in both sexes

Application of machine-learning model to optimize colonic adenoma detection in India

AIMS

There is limited data on the prevalence and risk factors of colonic adenoma from the Indian sub-continent. We aimed at developing a machine-learning model to optimize colonic adenoma detection in a prospective cohort.

METHODS

All consecutive adult patients undergoing diagnostic colonoscopy were enrolled between October 2020 and November 2022. Patients with a high risk of colonic adenoma were excluded. The predictive model was developed using the gradient-boosting machine (GBM)-learning method. The GBM model was optimized further by adjusting the learning rate and the number of trees and 10-fold cross-validation.

RESULTS

Total 10,320 patients (mean age 45.18 ± 14.82 years; 69% men) were included in the study. In the overall population, 1152 (11.2%) patients had at least one adenoma. In patients with age > 50 years, hospital-based adenoma prevalence was 19.5% (808/4144). The area under the receiver operating curve (AUC) (SD) of the logistic regression model was 72.55% (4.91), while the AUCs for deep learning, decision tree, random forest and gradient-boosted tree model were 76.25% (4.22%), 65.95% (4.01%), 79.38% (4.91%) and 84.76% (2.86%), respectively. After model optimization and cross-validation, the AUC of the gradient-boosted tree model has increased to 92.2% (1.1%).

CONCLUSIONS

Machine-learning models may predict colorectal adenoma more accurately than logistic regression. A machine-learning model may help optimize the use of colonoscopy to prevent colorectal cancers.

TRIAL REGISTRATION

ClinicalTrials.gov (ID: NCT04512729).

Therapeutic Carbohydrate Restriction as a Metabolic Modality for the Prevention and Treatment of Abnormal Uterine Bleeding

Therapeutic carbohydrate restriction diets have been becoming increasingly popular over the years, resulting in dramatic weight loss and an improvement in metabolic disorders. Obesity, insulin resistance, and diabetes are the risk factors for many gynecologic morbidities such as uterine leiomyoma, endometrial polyps, and polycystic ovarian syndrome. There is evidence suggesting that the pathogenesis of cardiovascular disease is similar to that seen in many causes of abnormal uterine bleeding. We aim to explain how cardiovascular disease risk factor reduction with the use of therapeutic carbohydrate restriction may prevent and potentially treat these gynecologic disorders.

Prognostic Value of Body Mass Index in Stage II/III Colon Cancer: Posthoc Analysis From the TOSCA Trial

BACKGROUND

High body mass index (BMI) plays a key role in the development of colon cancer (CC). Our post-hoc analysis from the TOSCA trial analyzed the association between BMI and survival outcomes in terms of relapse-free survival (RFS) and overall survival (OS) in stage II/III CC patients.

PATIENTS AND METHODS

Patients enrolled in the TOSCA trial between 2007-2013 with BMI data entered the study. The prognostic impact of BMI on survival outcomes was investigated through uni- and multivariable Cox regression analyses.

RESULTS

Overall, 1455 patients with stage II/III CC patients were included. The median follow-up was of 61.5 months; 16.1% of patients relapsed, 11.2% died and 19.5% patients relapsed or died. No impact of BMI on RFS was detected at univariate or multivariable analyses. By univariate analysis for OS, a significantly impact of a BMI > 30 kg/m² was reported (HR [>30 vs <25] 1.57, 95% CI 1.00-2.47, p = 0.049; HR [>30 vs <30] 1.55, 95% CI 1.01-2.37, p = 0.045). Multivariable analyses did not confirm this data. In the subgroup of stage III patients, a negative survival impact of BMI was found in univariate and multivariable models both for RFS and for OS.

CONCLUSIONS

In our study, obesity with BMI > 30 kg/m² was an independent prognostic factor for RFS and OS in CC patients treated with adjuvant chemotherapy, regardless of its duration (3 or 6 months). However, the prognostic impact of adiposity and body composition measurement should be considered to better classify patients with high visceral fat and refine their risk assessment.

Metabolic dysfunction and obesity-related cancer: Beyond obesity and metabolic syndrome

OBJECTIVES

The metabolic dysfunction driven by obesity, including hyperglycemia and dyslipidemia, increases risk for developing at least 13 cancer types. The concept of "metabolic dysfunction" is often defined by meeting various combinations of criteria for metabolic syndrome. However, the lack of a unified definition of metabolic dysfunction makes it difficult to compare findings across studies. This review summarizes 129 studies that evaluated variable definitions of metabolic dysfunction in relation to obesity-related cancer risk and mortality after a cancer diagnosis. Strategies for metabolic dysfunction management are also discussed.

METHODS

A comprehensive search of relevant publications in MEDLINE (PubMed) and Google Scholar with review of references was conducted.

RESULTS

Metabolic dysfunction, defined as metabolic syndrome diagnosis or any number of metabolic syndrome criteria out of clinical range, inflammatory biomarkers, or markers of metabolic organ function, has been associated with risk for, and mortality from, colorectal, pancreatic, postmenopausal breast, and bladder cancers. Metabolic dysfunction associations with breast and colorectal cancer risk have been observed independently of BMI, with increased risk in individuals with metabolically unhealthy normal weight or overweight/obesity compared with metabolically healthy normal weight.

CONCLUSION

Metabolic dysfunction is a key risk factor for obesity-related cancer, regardless of obesity status. Nonetheless, a harmonized definition of metabolic dysfunction will further clarify the magnitude of the relationship across cancer types, enable better comparisons across studies, and further guide criteria for obesity-related cancer risk stratification.

Metabolic syndrome and colorectal adenoma risk: A systematic review and meta‑analysis

OBJECTIVE

Whether metabolic syndrome is a risk factor of colorectal adenoma has spurred debate. We systematically meta-analyzed all clinical studies associated with metabolic syndrome (MetS)/metabolic components and colorectal adenoma risk and quantified the dose-response association between them, aiming to provide more clues for better decision-making.

METHODS

We searched PubMed, EMBASE, and Cochrane Library through June 2020 for clinical studies of MetS and colorectal adenoma risk. RevMan 5.3 software and STATA 12.0 software were employed for meta-analysis.

RESULTS

Seventeen studies representing 44,336 participants were eligible for analysis. The overall meta-analysis showed that MetS patients had increased risk of colorectal adenoma (OR: 1.39, 95% CI 1.24-1.57; P < 0.05). Dose-response analysis presented that every increased number of Mets components was associated with a 8% increment of colorectal adenoma risk(OR: 1.08; 95% CI: 1.04-1.11). Subgroup analysis by age revealed a higher colorectal adenoma risk in MetS patients 50 years or older (OR 1.46; 95% CI 1.21-1.76; P < 0.0001), rather than MetS patients younger than 50 years old (OR 1.23; 95% CI 0.95-1.59; P = 0.11).When stratified by sex, the analysis revealed a higher risk of colorectal adenoma in male MetS patients (OR 1.32; 95% CI 1.15-1.53; P = 0.0001), rather than females (OR 1.65; 95% CI 0.90-3.02; P = 0.10). The analysis split by adenoma location showed that the right colon (OR 1.35; 95% CI 1.04-1.75; P = 0.03), instead of the left colon (OR 1.16; 95% CI 0.84-1.59; P = 0.37) or rectum(OR 1.26; 95% CI 0.89-1.78; P = 0.20), was the predilection site associated with increased colorectal adenoma risk in MetS patients.

CONCLUSIONS

Overall, our meta-analysis showed that MetS was associated with a higher risk of colorectal adenoma. MetS patients, especially old (≥50 years) male patients, should be a risk population for colorectal adenoma screening so that they can benefit from behavioural interventions that can help prevent the development of colorectal cancer.

Racial/ethnic disparities in weight or BMI change in adulthood and pancreatic cancer incidence: The multiethnic cohort

INTRODUCTION

Compared to non-Hispanic Whites, Japanese Americans, Native Hawaiians, and African Americans have higher incidences of pancreatic cancer (PCa) that are not entirely explained by rates of obesity but may be explained by weight changes throughout adulthood.

METHODS

The multiethnic cohort is a population-based prospective cohort study that has followed 155,308 participants since its establishment between 1993 and 1996. A total of 1,328 incident cases with invasive PCa were identified through 2015. We conducted separate multivariable Cox proportional hazards models for self-reported weight-change and BMI-change (age 21 to cohort entry) to determine the association with PCa risk, adjusting for potential confounders including weight or BMI at age 21.

RESULTS

The mean age at cohort entry was 59.3 years (SD 8.9). An increased risk of PCa was associated with: 1) weight (HR per10 lbs = 1.06; 95% CI = 1.03-1.09) or BMI (HR per kg/m2  = 1.04; 95% CI = 1.02-1.05) at age 21; and 2) weight (HR per 10 lbs = 1.03; 95% CI = 1.01-1.05) or BMI (HR = 1.02; 95% CI = 1.00-1.03) at cohort entry. We found increased risk of PCa between weight (HR per 10 lbs = 1.03; 95% CI = 1.01-1.05) and BMI (HR per 5 kg/m2  = 1.08; 95% CI = 1.01-1.15) change from age 21 to baseline. There were significant interactions between race/ethnicity and weight (p = 0.008) or BMI (p = 0.03) at baseline, and weight (p = 0.02) or BMI (p = 0.02) change. Weight and BMI change through adulthood significantly increased the risk of PCa for Japanese Americans and Latinos, but not for African American, White, or Hawaiian participants.

CONCLUSION

Our findings indicate that weight or BMI gain has a significant and independent impact on PCa risk, specifically among Latinos and Japanese Americans.

Disparities in Early-Onset Colorectal Cancer

The incidence and mortality of early-onset colorectal cancer (CRC) are increasing in the United States (US) and worldwide. In the US, there are notable disparities in early-onset CRC burden by race/ethnicity and geography. African Americans, Hispanic/Latinos, and populations residing in specific regions of the Southern U.S. are disproportionately affected with CRC diagnosed at younger ages, while less is known about disparities in other countries. Reasons for these disparities are likely multi-factorial and potentially implicate differences in health determinants including biology/genetics, diet/environment, individual health behaviors, and access to high-quality health services, as well as social and policy factors. This review summarizes current understanding of early-onset CRC disparities and identifies specific research areas that will inform evidence-based interventions at individual, practice, and policy levels to reduce the global burden of this disease.

CT-based determination of excessive visceral adipose tissue is associated with an impaired survival in critically ill patients

Objective

Obesity is a negative prognostic factor for various clinical conditions. In this observational cohort study, we evaluated a CT-based assessment of the adipose tissue distribution as a potential non-invasive prognostic parameter in critical illness.

Methods

Routine CT-scans upon admission to the intensive care unit (ICU) were used to analyze the visceral and subcutaneous adipose tissue areas at the 3^rd lumbar vertebra in 155 patients. Results were correlated with various prognostic markers and both short-term- and overall survival. Multiple statistical tools were used for data analysis.

Results

We observed a significantly larger visceral adipose tissue area in septic patients compared to non-sepsis patients. Interestingly, patients requiring mechanical ventilation had a significantly higher amount of visceral adipose tissue correlating with the duration of mechanical ventilation. Moreover, both visceral and subcutaneous adipose tissue area significantly correlated with several laboratory markers. While neither the visceral nor the subcutaneous adipose tissue area was predictive for short-term ICU survival, patients with a visceral adipose tissue area above the optimal cut-off (241.4 cm²) had a significantly impaired overall survival compared to patients with a lower visceral adipose tissue area.

Conclusions

Our study supports a prognostic role of the individual adipose tissue distribution in critically ill patients. However, additional investigations need to confirm our suggestion that routine CT-based assessment of adipose tissue distribution can be used to yield further information on the patients’ clinical course. Moreover, future studies should address functional and metabolic analysis of different adipose tissue compartments in critical illness.

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

OBJECTIVE

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

High expression of FABP4 in colorectal cancer and its clinical significance

OBJECTIVES

To investigate the relationship between the fatty acid-binding protein 4 (FABP4) and colorectal cancer (CRC).

METHODS

Using an enzyme-linked immunosorbent assay (ELISA), we measured the expression of FABP4 in plasma of 50 patients who underwent surgery for CRC from October 2017 to May 2018 and 50 healthy controls. The content of the visceral fat area (VFA) as seen with abdominal computed tomography (CT) scanning was measured by ImageJ software. The expression levels of FABP4, E-cadherin, and Snail proteins in CRC and adjacent tissues were determined by immunohistochemistry.

RESULTS

The mean concentration of plasma FABP4 of CRC patients was higher than that of the control group (22.46 vs. 9.82 ng/mL; P<0.05). The concentration of plasma FABP4 was related to the tumor, node, metastatis (TNM) stage and lymph node metastasis and was independent of age, body mass index (BMI), tumor size and location, and the degree of differentiation of CRC. The concentration of plasma FABP4 was positively correlated with high VFA and lipoprotein-a (LPA) (P<0.05); but it was not correlated with total cholesterol (TG), total triglyceride (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), or apolipoprotein AI (Apo-AI). The expression of FABP4 protein in CRC tissues was positively correlated with the degree of CRC differentiation, tumor stage, and lymph node metastasis. The level of FABP4 protein was negatively correlated with E-cadherin protein (r=-0.3292, P=0.0196) and positively correlated with Snail protein (r=0.5856, P<0.0001).

CONCLUSIONS

High LPA and VFA were risk factors for increased plasma FABP4 in CRC patients. FABP4 protein was highly expressed in CRC tissues and associated with TNM stage, differentiation, and lymph node metastasis of CRC. The level of FABP4 in CRC tissue was correlated with E-cadherin and Snail expression, suggesting that FABP4 may promote CRC progression related to epithelial-mesenchymal transition (EMT).

Lipid Metabolism as a Targetable Metabolic Vulnerability in Colorectal Cancer

Colorectal cancer (CRC), the second leading cause of cancer-related deaths according to the World Health Organization, remains a substantial public health problem worldwide [...].

Opportunistic use of radiological measures of visceral adiposity for assessment of risk of colorectal adenoma

BACKGROUND

Recent evidence suggested that radiological measures of visceral adiposity are a better tool for risk assessment of colorectal adenomas. The aim of this study was to investigate the association of visceral adiposity with the development of colorectal adenomas.

METHODS

A retrospective review of all cases of computed tomography-confirmed acute diverticulitis from November 2015 to April 2018 was performed. Data collated included basic demographics, computed tomography scan results (uncomplicated versus complicated diverticulitis), treatment modality (conservative versus intervention), outcomes and follow-up colonoscopy results within 12 months of presentation. The patients were divided into no adenoma (A) and adenoma (B) groups. Visceral fat area (VFA), subcutaneous fat area (SFA) and VFA/SFA ratio (V/S) were measured at L4/L5 level. Statistical analysis was performed to evaluation the association of VFA, SFA, V/S and different thresholds with the risk of adenoma formation.

RESULTS

A total of 169 patients were included in this study (A:B = 123:46). The mean ± standard deviation for VFA was higher in group B (201 ± 87 cm² versus 176 ± 79 cm² ) with a trend towards statistical significance (P = 0.08). There was no difference in SFA and V/S in both groups. When the VFA >200 cm² was analysed, it was associated with a threefold risk of adenoma formation (odds ratio 2.7, 95% confidence interval 1.35-5.50, P = 0.006). Subgroup analysis of gender with VFA, SFA and V/S found that males have a significantly higher VFA in group B (220.0 ± 95.2 cm² versus 187.3 ± 69.2 cm² ; P = 0.05).

CONCLUSIONS

The radiological measurement of visceral adiposity is a useful tool for opportunistic assessment of risk of colorectal adenoma.

Severe loss of visceral fat and skeletal muscle after chemotherapy predicts poor prognosis in metastatic gastric cancer patients without gastrectomy

Background: The influence of body composition parameters in cancer prognosis attracted researchers' attention. This study investigated the role of visceral fat and skeletal muscle in the prognosis and efficacy of chemotherapy in metastatic gastric cancer (MGC). Methods: This study included MGC patients without gastrectomy treated with EOF regimen (epirubicin, oxaliplatin and fluorouracil), who participated in a Phase II clinical trial (NCT00767377) with available PACS image data. The visceral fat area (VFA) and skeletal muscle area (SMA) were measured using standard computed tomography (CT). Results: A total of 46 patients were enrolled in the study. Patients with low baseline VFA and SMA had significantly shorter PFS and OS. In addition, the loss of VFA and SMA also predicts significantly shorter PFS and OS. A prognostic index that included two risk factors, severe loss of VFA and SMA, was used to categorize the patients into two groups: good-risk group (0 risk factors), poor-risk group (1 or 2 risk factors). Compared with the good-risk group, the poor-risk group displayed a 3.562-fold-increased risk of progression [hazard ratio (HR) 3.652, 95 % CI 1.653-7.678; P =0.001] and 2.859-fold-increased risk of death [hazard ratio (HR) 2.859, 95 % CI 1.271-6.434; P =0.011]. Conclusion: Low baseline VFA and SMA, as well as the severe loss of VFA and SMA predict poor prognosis for MGC patients treated by EOF regimen. In patients with severe loss of VFA and/or SMA after 2-cycle chemotherapy, the decision of subsequent chemotherapy should be made after deliberate consideration.

Is visceral obesity associated with colorectal cancer? The first volumetric study using all CT slices

PURPOSE

We aimed to examine the possible relationship between abdominal adiposity parameters and the presence of colorectal cancer (CRC) and between these adiposity parameters and various histopathologic findings of the tumor.

METHODS

A total of 60 control subjects and 111 CRC patients, 63 with early-stage and 48 with advanced-stage disease, were enrolled. Medical data and abdominopelvic computed tomography (CT) examinations of each study group were retrospectively reviewed. Abdominal adiposity parameters, including visceral adipose tissue (VAT) volume, subcutaneous adipose tissue (SAT) volume, and total adipose tissue (TAT) volume, were calculated on all slices of the CT examinations with specialized software, and results for each study group were compared. Adiposity parameters were also compared with tumor histopathologic findings.

RESULTS

We found lower VAT and higher SAT volumes in advanced-stage CRC patients, compared with the early-stage group. However, this relationship was not statistically significant (P = 0.721 for VAT and P = 0.432 for SAT volumes). We detected significantly lower VAT and SAT volumes in the early-stage CRC group compared with the control group (P = 0.014 for both). There was no significant relationship between TAT volumes and the study groups (P = 0.06). No statistically significant relationship was detected between adipose tissue parameters and histopathologic features of the CRC group (P > 0.05).

CONCLUSION

We found statistically significant lower VAT and SAT volumes in patients with early-stage CRC compared with the control group. Volumetric adipose tissue measurements may be more accurate than area measurements and can easily be performed on abdominopelvic CT examination, which is the routine imaging modality for CRC patients.

Global patterns and trends in colorectal cancer incidence in young adults

OBJECTIVE

Early-onset colorectal cancer (CRC) is increasing in the USA despite rapid declines in older ages. Similar patterns are reported in Australia and Canada, but a comprehensive global analysis of contemporary data is lacking.

DESIGN

We extracted long-term data from Cancer Incidence in Five Continents and supplemental sources to report on worldwide CRC incidence rates and trends by age (20-49 years and ≥50 years) through diagnosis year 2012 or beyond (Australia, Finland, New Zealand, Norway, Sweden, USA).

RESULTS

During 2008-2012, age-standardised CRC incidence rates in adults <50 ranged from 3.5 per 100 000 (95% CI 3.2 to 3.9) in India (Chennai) to 12.9 (95% CI 12.6 to 13.3) in Korea. During the most recent decade of available data, incidence in adults <50 was stable in 14 of 36 countries; declined in Austria, Italy and Lithuania; and increased in 19 countries, nine of which had stable or declining trends in older adults (Australia, Canada, Denmark, Germany, New Zealand, Slovenia, Sweden, UK and USA). In Cyprus, Netherlands and Norway, inclines in incidence in young adults were twice as rapid as those in older adults (eg, Norway average annual per cent change (AAPC), 1.9 (95% CI 1.4 to 2.5) vs 0.5 (95% CI 0.3 to 0.7)). Among most high-income countries with long-term data, the uptick in early-onset disease began in the mid-1990s. The steepest increases in young adults were in Korea (AAPC, 4.2 (95% CI 3.4 to 5.0)) and New Zealand (AAPC, 4.0 (95% CI 2.1 to 6.0)).

CONCLUSION

CRC incidence increased exclusively in young adults in nine high-income countries spanning three continents, potentially signalling changes in early-life exposures that influence large bowel carcinogenesis.

Changes in lipids composition and metabolism in colorectal cancer: a review

Altered metabolism of lipids is currently considered a hallmark characteristic of many malignancies, including colorectal cancer (CRC). Lipids are a large group of metabolites that differ in terms of their fatty acid composition. This review summarizes recent evidence, documenting many alterations in the content and composition of fatty acids, polar lipids, oxylipins and triacylglycerols in CRC patients' sera, tumor tissues and adipose tissue. Some of altered lipid molecules may be potential biomarkers of CRC risk, development and progression. Owing to a significant role of many lipids in cancer cell metabolism, some of lipid metabolism pathways may also constitute specific targets for anti-CRC therapy.

Impact of sarcopenia on the risk of advanced colorectal neoplasia

BACKGROUND AND AIM

Sarcopenia is a pathological condition characterized by the progressive loss of muscle mass and increased amount of visceral fat. Recent evidence has revealed that sarcopenia is associated with certain diseases. However, the impact of sarcopenia on colorectal neoplasia has not been documented clearly. We studied the association between sarcopenia and advanced colorectal neoplasia in a large screening population.

METHODS

This cross-sectional study included 14 024 asymptomatic adults who underwent first-time screening colonoscopy. Sarcopenia (class II) was defined as an appendicular skeletal muscle mass (ASM)/bodyweight (%) value more than two standard deviations below the mean for healthy young adults. ASM was estimated using bioelectrical impedance analysis.

RESULTS

In a multivariable model adjusted for age, sex, obesity (body mass index ≥ 25), smoking status, alcohol intake, regular exercise, and family history of colorectal cancer, the odds ratio (OR) for advanced colorectal neoplasia on comparing participants with sarcopenia (class II) to those without sarcopenia (class I + II) was 1.52 (95% confidence interval [CI], 1.23-1.86). Further adjustment for metabolic parameters attenuated this association, but the association was still significant (OR, 1.34; 95% CI, 1.07-1.68). Furthermore, the multivariable (traditional risk factors)-adjusted OR associated with a 1% decrease on the introduction of ASM/weight% as a continuous variable in regression models was 1.04 (95% CI, 1.01-1.07) for advanced colorectal neoplasia.

CONCLUSIONS

Our findings indicate that sarcopenia is significantly and progressively associated with the risk of advanced colorectal neoplasia. This association might be explained by metabolic factors that could be potential mediators of the effect of sarcopenia.

Metabolic syndrome is a risk factor for colorectal adenoma and cancer: a study in a White population using the harmonized criteria

BACKGROUND

Metabolic syndrome (MetS) has been associated with colorectal adenomas and cancer. However, MetS definitions have changed over time, leading to a heterogeneity of patients included in previous studies and a substantial inextensibility of observations across time or eastern and western populations. Our aim was to evaluate the association of 'harmonized' criteria-defined MetS and its individual components with colorectal neoplasia and cancer in a western population.

METHODS

In this multicenter, cross-sectional study, we prospectively evaluated consecutive outpatients who underwent open-access colonoscopy over a 3-month period. MetS was diagnosed according to the 2009 'harmonized' criteria.

RESULTS

Out of 5707 patients enrolled, we found 213 cancers (3.7%), 1614 polyps (28.3%), 240 nonpolypoid lesions (4.2%), 95 laterally spreading tumors (1.6%). Polyps presented histological low-grade dysplasia in 72.9% of samples, while in 9.8%, high-grade dysplasia or in situ carcinoma was present; dysplasia rates for nonpolypoid lesions were 66.2% (low-grade) and 2.9% (high-grade/in situ carcinoma), while for laterally spreading tumors, 29.6% and 37%, respectively. Overall, MetS prevalence was 41.6%. MetS correlated with both adenomas [odds ratio (OR): 1.76, 95% confidence interval (CI) 1.54-2.00] and cancer (OR: 1.92, 95% CI 1.42-2.58). MetS was the only risk factor for such colonic lesions in subjects younger than 50 years. For all colonic neoplasia, we found MetS and not its individual components to be significantly associated.

CONCLUSIONS

MetS is risk factor for cancer and adenoma in Whites, especially when younger than 50 years. MetS patients might be considered as a high-risk population also in colorectal cancer screening programs.

Association of visceral adiposity and insulin resistance with colorectal adenoma and colorectal cancer

BACKGROUND/AIMS

To examine whether visceral adiposity serves as a risk factor for colorectal cancer (CRC) and colorectal adenomas.

METHODS

Two hundred healthy subjects, 200 patients with colorectal adenoma, and 151 patients with CRC (46 with early-stage and 105 with advanced-stage cancers) were enrolled at a tertiary referral hospital. All subjects underwent colonoscopy, and had laboratory data, and computed tomography (CT) scan available for abdominal fat measurement. An abdominal CT scan taken 1 to 4 years (mean interval, 20.6 months) before the diagnosis of CRC was also available in the 42 CRC patients.

RESULTS

The mean areas of visceral adipose tissue (VAT) areas in the control, adenoma, early- and advanced-stage CRC groups were 94.6, 116.8, 110.4, and 99.7 cm2 , respectively (P<0.001). The risk of adenoma positively correlated with VAT area and the visceral-to-total fat ratio (P for trend <0.01), but the risk of CRC did not (P>0.05). The risk of both adenoma and CRC positively correlated with fasting plasma glucose levels (P for trend <0.05). In patients with early-stage cancer (n=17), VAT area decreased when the CT scan at diagnosis was compared with that taken before the diagnosis of CRC, but superficial adipose tissue area did not, so visceral-to-total fat ratio significantly decreased (46.6% vs. 50.7%, respectively, P=0.018).

CONCLUSIONS

VAT area is related to the risk of colorectal adenoma. However, VAT decreases from the early stages of CRC. Impaired fasting glucose has a role in colorectal carcinogenesis.

Sex differences in associations among metabolic syndrome, obesity, related biomarkers, and colorectal adenomatous polyp risk in a Japanese population

To investigate sex differences in the associations among metabolic syndrome, obesity, adipose tissue-related biomarkers, and colorectal adenomatous polyps, a cross-sectional, multicenter study was conducted on 489 consecutive individuals who underwent their first colonoscopy at 3 hospitals. Plasma concentrations of adiponectin and leptin, as well as homeostatic model assessment of insulin resistance were also evaluated. The presence and number of adenomatous polyps, including advanced adenoma, were higher in men than in women. Metabolic syndrome was a risk factor for adenomatous polyps in both sexes. Large waist circumference was an independent risk factor for adenomatous polyps in men, and high BMI and large waist circumference were risk factors for adenomatous polyps in women. Interestingly, low BMI was associated with large adenomatous polyps (≥10 mm) and advanced adenoma, and waist-hip ratio was involved in proximal adenomatous polyp development only in women. In contrast, the highest quartile of leptin concentration had a 3.67-fold increased adenomatous polyp risk compared with the lowest quartile only in men. These results indicate that regarding colorectal pathogenesis, sex differences were identified in obesity but not in metabolic syndrome. Visceral obesity and a high serum leptin level may be risk factors for colorectal adenomatous polyp development in Japanese men.

Spontaneous Expulsion per Rectum of a Colorectal Polyp: A Rare and Unusual Case

Colorectal polyps are growths that form on the epithelium of the colon and rectum. While their prevalence varies considerably from region to region, they are common in adults. In fact, among asymptomatic, average-risk individuals at 50 years of age, the prevalence of colorectal polyps averages roughly 10% in sigmoidoscopy studies and more than 25% in colonoscopy studies. Approximately two-thirds of all colorectal polyps are adenomatous precancerous lesions that have the potential to become malignant. Usually, they are discovered and resected during colonoscopy. The spontaneous expulsion per rectum of a colorectal polyp is exceedingly rare. Here, we report a rare and unusual case that we believe is the first of spontaneous expulsion of an adenomatous polyp during defecation. These patients should undergo colonoscopy to search for additional polyps as well as other gastrointestinal pathology.

Sex differences in associations among metabolic syndrome, obesity, related biomarkers, and colorectal adenomatous polyp risk in a Japanese population

To investigate sex differences in the associations among metabolic syndrome, obesity, adipose tissue-related biomarkers, and colorectal adenomatous polyps, a cross-sectional, multicenter study was conducted on 489 consecutive individuals who underwent their first colonoscopy at 3 hospitals. Plasma concentrations of adiponectin and leptin, as well as homeostatic model assessment of insulin resistance were also evaluated. The presence and number of adenomatous polyps, including advanced adenoma, were higher in men than in women. Metabolic syndrome was a risk factor for adenomatous polyps in both sexes. Large waist circumference was an independent risk factor for adenomatous polyps in men, and high BMI and large waist circumference were risk factors for adenomatous polyps in women. Interestingly, low BMI was associated with large adenomatous polyps (≥10 mm) and advanced adenoma, and waist-hip ratio was involved in proximal adenomatous polyp development only in women. In contrast, the highest quartile of leptin concentration had a 3.67-fold increased adenomatous polyp risk compared with the lowest quartile only in men. These results indicate that regarding colorectal pathogenesis, sex differences were identified in obesity but not in metabolic syndrome. Visceral obesity and a high serum leptin level may be risk factors for colorectal adenomatous polyp development in Japanese men.

Obesity-Related Digestive Diseases and Their Pathophysiology

Obesity is a growing medical and public health problem worldwide. Many digestive diseases are related to obesity. In this article, the current state of our knowledge of obesity-related digestive diseases, their pathogenesis, and the medical and metabolic consequences of weight reduction are discussed. Obesity-related digestive diseases include gastroesophageal reflux disease, Barrett’s esophagus, esophageal cancer, colon polyp and cancer, nonalcoholic fatty liver disease, hepatitis C-related disease, hepatocellular carcinoma, gallstone, cholangiocarcinoma, and pancreatic cancer. Although obesity-related esophageal diseases are associated with altered mechanical and humoral factors, other obesity-related digestive diseases seem to be associated with obesity-induced altered circulating levels of adipocytokines and insulin resistance. The relationship between functional gastrointestinal disease and obesity has been debated. This review provides a comprehensive evaluation of the obesity-related digestive diseases, including pathophysiology, obesity-related risk, and medical and metabolic effects of weight reduction in obese subjects.

Obesity, Thrombotic Risk, and Inflammation in Cancer

Neoplasms exhibits a high incidence and mortality rates due to their complex and commonly overlapping clinical, biochemical, and morphologic profiles influenced by acquired or inherited molecular abnormalities, cell of origin, and level of differentiation. Obesity appears related to ~20% of cancers including endometrial, esophageal, colorectal, postmenopausal breast, prostate, and renal. Several factors other than obesity, i.e., insulin, insulin-like growth factor, sexual hormones, and adipokines may play a potential role in neoplasia. Cancer-associated hypercoagulable and thrombotic states are influenced by abnormalities in the vascular wall and susceptibility to invasion, interference in blood flow and increase in circulating tissue factor and thrombin, activation of cell growth factors, the presence of a central catheter, chemotherapies, neoplasm type, and surgery. In cancer, thromboembolic complications are the second most frequent cause of death with pulmonary thromboembolism in ~50% of cases postmortem. Thrombosis worsens prognosis as demonstrated with a survival rate as low as 12% per year vs 36% in nonthrombic patients. Deep vein thrombosis is the most frequent thromboembolic complication in cancer. It is usually detected at diagnosis and within the first 3 months of chemotherapy. The underlining mechanisms of this association should be further studied to identify patients at higher risk and develop adequate prevention, diagnostic, and treatment measures. The D-dimer test can be successfully used to assess the fibrinolytic phase of coagulation and as such is routinely used in suspected cases of deep vein thrombosis and pulmonary thromboembolism. In addition, significant advances have been made in understanding the composition and functional capabilities of the gut microbiota in the inflammatory process, obesity, and its roles in cancer; however, the intricate balance that exists within the microbiota may not only affect the host directly, it can also disrupt the entire microbial community.

CONCLUSIONS

Cancer is a prothrombotic and inflammatory state in which the activation of coagulation is related to tumor growth, angiogenesis, and metastasis. It is important to identify the relationship between body mass index with these processes and clarify their importance in cancer prognosis. Future research should answer the question if manipulation of resident microbial communities could potentially improve prognosis and treatment outcome.

Association between investigator-measured body-mass index and colorectal adenoma: a systematic review and meta-analysis of 168,201 subjects

The objective of this meta-analysis is to evaluate the odds of colorectal adenoma (CRA) in colorectal cancer screening participants with different body mass index (BMI) levels, and examine if this association was different according to gender and ethnicity. The EMBASE and MEDLINE were searched to enroll high quality observational studies that examined the association between investigator-measured BMI and colonoscopy-diagnosed CRA. Data were independently extracted by two reviewers. A random-effects meta-analysis was conducted to estimate the summary odds ratio (SOR) for the association between BMI and CRA. The Cochran’s Q statistic and I² analyses were used to assess the heterogeneity. A total of 17 studies (168,201 subjects) were included. When compared with subjects having BMI < 25, individuals with BMI 25–30 had significantly higher risk of CRA (SOR 1.44, 95% CI 1.30–1.61; I² = 43.0%). Subjects with BMI ≥ 30 had similarly higher risk of CRA (SOR 1.42, 95% CI 1.24–1.63; I² = 18.5%). The heterogeneity was mild to moderate among studies. The associations were significantly higher than estimates by previous meta-analyses. There was no publication bias detected (Egger’s regression test, p = 0.584). Subgroup analysis showed that the magnitude of association was significantly higher in female than male subjects (SOR 1.43, 95% CI 1.30–1.58 vs. SOR 1.16, 95% CI 1.07–1.24; different among different ethnic groups (SOR 1.72, 1.44 and 0.88 in White, Asians and Africans, respectively) being insignificant in Africans; and no difference exists among different study designs. In summary, the risk conferred by BMI for CRA was significantly higher than that reported previously. These findings bear implications in CRA risk estimation.

Obesity-related parameters and colorectal adenoma development

BACKGROUND

Obesity increases the risk of colorectal adenoma and colorectal cancer. However, the obesity-related parameters that are best for assessing the risk of colorectal adenoma development remain unclear. We analyzed the parameters that may best describe the association between obesity and colorectal adenoma development.

METHODS

In this retrospective cohort study, 3405 individuals underwent screening colonoscopy during routine health examinations. We measured body mass index; waist circumference; and metabolic parameters such as high-density lipoprotein-cholesterol, glucose, triglyceride, and systolic blood pressure. We analyzed the risk of developing colorectal adenoma, relative to obesity-related parameters, over a mean interval of 5.8 years from baseline colonoscopy.

RESULTS

In a multivariate analysis, waist circumference was the only obesity-related marker associated with an increased risk of metachronous colorectal adenoma. Men with waist circumferences ≥85 cm and women with waist circumference ≥82 cm had a 31% increased risk of metachronous colorectal adenoma compared to those with smaller waist circumferences [odds ratio (OR) 1.31; 95% confidence interval (CI, 1.09-1.57)]. Other factors associated with metachronous colorectal adenoma were age (OR, 1.03; 95% CI 1.02-1.04), male sex (OR 1.49; 95% CI 1.17-1.88), alcohol consumption ≥3/week (OR 1.33; 95% CI 1.10-1.62), the number of adenoma at baseline (OR 1.21; 95% CI 1.10-1.33), and the presence of advanced adenoma at baseline (OR 1.60; 95% CI 1.24-2.06).

CONCLUSIONS

Our findings suggest that central obesity, represented by waist circumference, is a significant predictor of metachronous colorectal adenoma, independent of body mass index and other metabolic variables.

Effect of Weight Gain and Weight Loss on In Vivo Colonocyte Proliferation Rate in People with Obesity

OBJECTIVE

To evaluate the effects of diet-induced changes in energy balance and body weight on in vivo colonocyte fractional proliferation rates (FPR) in people with obesity.

METHODS

In vivo colonocyte FPR was assessed in 31 men and women with obesity (BMI: 35.4 ± 4.0 kg/m2 , age: 52.6 ± 8.9 years) before and after diet-induced weight loss, weight gain, or weight maintenance. Subjects ingested aliquots of 2 H2 O (heavy water) daily for 4 to 7 days, followed by flexible sigmoidoscopy with colon biopsies to assess the incorporation of 2 H into the DNA of dividing colonocytes.

RESULTS

Colonocyte FPR averaged 12.7% ± 3.8% per day and correlated directly with intra-abdominal adipose tissue (IAAT) volume (r = 0.364, P = 0.044). Colonocyte FPR decreased in the weight loss group, did not change in the weight maintenance group, and increased in the weight gain group. The change in colonocyte FPR correlated directly with the percent change in body weight (r = 0.409, P = 0.028) and IAAT volume (r = 0.598, P = 0.001).

CONCLUSIONS

A high-calorie diet and weight gain increase, whereas a low-calorie diet and weight loss decrease, in vivo colonocyte proliferation rate in people with obesity. These results suggest that changes in energy balance influence the risk of developing colon cancer in people with obesity by regulating colonic mucosal growth rates.

Abdominal fat distribution measured using computed tomography is associated with an increased risk of colorectal adenoma in men

A few studies have shown inconsistent results regarding the association between the visceral fat proportion and colorectal adenomas. We aimed to investigate the association between abdominal fat distribution measured by computed tomography (CT) and colon adenoma.A total of 336 participants underwent physical examination, blood tests, colonoscopy, and abdominal computed tomography at Chung-Ang University Hospital. The associations between the obesity indicies (body mass index, visceral fat area (VFA), subcutaneous fat area (SFA), VFA-to-SFA ratio (VFA/SFA), and colorectal adenomas were evaluated.Of 309 subjects, 119 patients (38.5%) had colorectal adenoma. Mean age and fasting plasma glucose were higher in the patients with colorectal adenoma (P < .05, respectively). The mean VFA (153.3 cm vs 131.4 cm, P < .01) and VFA/SFA (1.07 vs 0.92, P < .05) were higher in the adenoma group than in the nonadenoma group. Males had higher mean VFA and VFA/SFA (P < .001). The mean VFA, SFA, and VFA/SFA were not associated with the location, size, number, and advancement of colorectal adenoma. In multivariate analysis, colorectal adenoma was significantly associated with VFA rather than VFA/SFA. In addition, colorectal adenoma was significantly associated with VFA rather than VFA/SFA in the men. The VFA, SFA, and VFA/SFA were not associated with colorectal adenoma in the women.The VFA measured by using a CT scan was positively associated with the presence of colorectal adenoma, especially in men. Furthermore, average risk men with large visceral fat volume should be examined carefully in screening colonoscopy.

Obesity Increases Prevalence of Colonic Adenomas at Screening Colonoscopy: A Canadian Community-Based Study

BACKGROUND AND AIMS

Obesity is a risk factor for colorectal neoplasia. We examined the influence of obesity and metabolic syndrome (MetS) on prevalence of neoplasia at screening colonoscopy.

METHODS

We evaluated 2020 subjects undergoing first screening colonoscopy. Body mass index (BMI) was calculated at enrolment. Hyperlipidemia (HL), hypertension (HT), and diabetes mellitus (DM) were identified. Details of colonoscopy, polypectomy, and histology were recorded. Odds for adenomas (A) and advanced adenomas (ADV) in overweight (BMI 25.1-30) and obese (BMI > 30) subjects were assessed by multinomial regression, adjusted for covariates. Analyses included relationships between HL, HT, DM, age, tobacco usage, and neoplasia. Discriminatory power of HT, HL, DM, and BMI for neoplasia was assessed by binary logistic regression. Odds were calculated for neoplasia in each colonic segment related to BMI.

RESULTS

A and ADV were commoner in overweight and obese males, obese females, older subjects, and smokers. HL, HT, and DM were associated with increased odds for neoplasia, significantly for A with hypertension. BMI alone predicted neoplasia as well as HT, HL, DM, or combinations thereof. All segments of the colon were affected. Multiple polyps were particularly prevalent in the obese.

CONCLUSIONS

Obesity and MetS are risk factors for colonic neoplasia in a Canadian population.

Impact of visceral obesity and metabolic syndrome on the postoperative immune, inflammatory, and endocrine response following surgery for esophageal adenocarcinoma

Visceral obesity and metabolic syndrome (MetSyn) represent a constellation of inflammation, insulin resistance, and hyperglycemia and are established risk factors for gastrointestinal cancer. However, their impact on the immune and inflammatory response after major upper gastrointestinal oncologic surgery is unknown. In 125 consecutive patients who underwent esophagectomy, C-reactive protein (CRP) and CRP:albumin levels were recorded preoperatively and on days 1, 3, 7, and 14 postoperatively. In a subset of 30 patients, circulating levels of IL-6, IL-8, IL-10, IL-12p70, IFN-γ, TNF-α, TGF-β, and cortisol were measured. Incidences of postoperative complications were prospectively recorded. In the study cohort, 51% of patients were viscerally obese, 40.7% had MetSyn, and 33.6% were hyperglycemic. Viscerally obese and MetSyn-positive patients demonstrated greater postoperative CRP levels and CRP:albumin levels on day 7 and day 14 compared with nonobese and MetSyn-negative patients (P < 0.05). Higher postoperative circulating levels of cortisol were observed in the viscerally obese and hyperglycemic patients compared to nonobese and normoglycemic patients. No association was observed between visceral obesity, MetSyn or hyperglycemia, and postoperative cytokine profile. Viscerally obese patients had an increased overall incidence of postoperative complications compared to nonobese patients (67.2% vs. 47.5%, P = 0.031) on univariate but not multivariate analysis (P = 0.078) and visceral obesity was not associated with an increased incidence of specific complications. Visceral obesity, MetSyn, and hyperglycemia are prevalent in patients undergoing major upper gastrointestinal resection and are associated with an exaggerated acute-phase inflammatory response postoperatively. Further research is warranted to determine whether this association is directly causal.

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

Whether 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.

Glucose metabolism of visceral adipose tissue measured by 18F-FDG PET/CT is related to the presence of colonic adenoma

This study investigated the relationships between the area and metabolic activity of adipose tissue and the presence of colorectal adenoma (CRA). Our institutional review board approved the study and waived informed consent. A total of 212 subjects who underwent fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and colonoscopy for routine health check-ups were enrolled. The volumetric parameters of areas of visceral (VATav), subcutaneous (SATav), and total adipose tissue (TATav) and calculated visceral-to-subcutaneous adipose tissue ratio (VSR) and visceral-to-total adipose tissue ratio (VAR) were considered. Metabolic parameters of standardized uptake value (SUV) of visceral (vcSUVmax, vcSUVmean), subcutaneous (scSUVmax, scSUVmean), and calculated visceral-to-subcutaneous adipose tissue ratio (VSRmax, VSRmean) were considered. Anthropometric data of height, weight, body mass index (BMI), waist circumference (WC), body fat mass (BFM), skeletal muscle mass (SMM), and diverse laboratory data were also considered as variables. Sixty-six subjects were placed in the CRA group and 146 subjects in the non-CRA group. The presence of CRA was significantly correlated with older age (P  =  .001), male sex (P  =  .041), higher BMI (P  =  .004), higher WC (P  =  .001), higher BFM (P  =  .024), higher VATav (P < .001), higher TATav (P  =  .004), higher VSR (P < .001), higher VAR (P < .001), lower vcSUVmax (P  =  .002), lower vcSUVmean (P < .001), and lower VSRmean (P  =  .002). On multiple regression analysis, vcSUVmax and vcSUVmean were independently associated with the presence of CRA (P  =  .009 and P  =  .045). Lower glucose metabolism of visceral adipose tissue was related to the presence of CRA. Our findings identify the value of visceral metabolic dysfunction as a potential surrogate marker of elevated risk for CRA.

Predictors for difficult cecal insertion in colonoscopy: The impact of obesity indices

AIM

To identify the factors influencing cecal insertion time (CIT) and to evaluate the effect of obesity indices on CIT.

METHODS

We retrospectively reviewed the data for participants who received both colonoscopy and abdominal computed tomography (CT) from February 2008 to May 2008 as part of a comprehensive health screening program. Age, gender, obesity indices [body mass index (BMI), waist-to-hip circumference ratio (WHR), waist circumference (WC), visceral adipose tissue (VAT) volume and subcutaneous adipose tissue (SAT) volume on abdominal CT], history of prior abdominal surgery, constipation, experience of the colonoscopist, quality of bowel preparation, diverticulosis and time required to reach the cecum were analyzed. CIT was categorized as longer than 10 min (prolonged CIT) and shorter than or equal to 10 min, and then the factors that required a CIT longer than 10 min were examined.

RESULTS

A total of 1678 participants were enrolled. The mean age was 50.42 ± 9.931 years and 60.3% were men. The mean BMI, WHR, WC, VAT volume and SAT volume were 23.92 ± 2.964 kg/m², 0.90 ± 0.076, 86.95 ± 8.030 cm, 905.29 ± 475.220 cm³ and 1707.72 ± 576.550 cm³, respectively. The number of patients who underwent abdominal surgery was 268 (16.0%). Colonoscopy was performed by an attending physician alone in 61.9% of cases and with the involvement of a fellow in 38.1% of cases. The median CIT was 7 min (range 2-56 min, IQR 5-10 min), and mean CIT was 8.58 ± 5.291 min. Being female, BMI, VAT volume and involvement of fellow were significantly associated with a prolonged CIT in univariable analysis. In multivariable analysis, being female (OR = 1.29, P = 0.047), lower BMI (< 23 kg/m²) (OR = 1.62, P = 0.004) or higher BMI (≥ 25 kg/m²) (OR = 1.80, P < 0.001), low VAT volume (< 500 cm³) (OR = 1.50, P = 0.013) and fellow involvement (OR = 1.73, P < 0.001) were significant predictors of prolonged CIT. In subgroup analyses for gender, lower BMI or higher BMI and fellow involvement were predictors for prolonged CIT in both genders. However, low VAT volume was associated with prolonged CIT in only women (OR = 1.54, P = 0.034).

CONCLUSION

Being female, having a lower or higher BMI than the normal range, a low VAT volume, and fellow involvement were predictors of a longer CIT.

Impact of Abdominal Adipose Depots and Race on Risk for Colorectal Cancer: A Case-Control Study

Visceral adipose tissue (VAT) but not subcutaneous adipose tissue (SAT) is associated with obesity-related diseases including colorectal cancer (CRC). Superficial SAT (SSAT) and deep SAT (DSAT), components of SAT, also appear to independently influence disease risk. These abdominal adipose tissues (AATs) are not extensively studied in connection with CRC and have not been explored in the United States despite known racial variations in body composition. We conducted a case-control study that compared associations between AAT with CRC risk and race of African-American (AA) and non-Hispanic white (NHW) men with incident CRC matched by age, body mass index, and race (N = 158, 79/group). Cross-sectional computed tomography images were used for assessment of AAT. Overall cases and controls had similar VAT areas (140 ± 192 vs 149 ± 152 cm², P-value = 0.93); however, cases had lower SSAT than controls (88 ± 39 vs 112 ± 65 cm², P < 0.01). Among controls, AA had significantly lower VAT (114 ± 168 vs 180 ± 167, P < 0.01) than NHW. Conditional logistic regression revealed that AA men with greater SSAT had lower odds for CRC (odds ratio [OR]: 0.24, 95% confidence interval [CI] 0.07-0.85). Our findings indicate that VAT does vary between cases and controls by race; however, this variation is not a risk factor for CRC. The negative association between CRC and SSAT in AA men warrants further investigation.

Clinical risk assessment for gastric cancer in asymptomatic population after a health check-up: An individualized consideration of the risk factors

For the prevention of gastric cancer, the detection of risk factors associated with precancerous conditions may be more informative. The aim of this study was to identify the risk factors of gastric cancer, including precancerous conditions: atrophic gastritis (AG), intestinal metaplasia (IM), and dysplasia.The clinical and endoscopic findings of 60,261 adults who underwent gastroduodenoscopy as part of a health check-up were reviewed retrospectively. Subgroup analysis was conducted according to age, sex, cancer stage, and histology based on Lauren classification.Gastric cancer was diagnosed in 75 patients (0.12%). Both IM and AG were independent risk factors for gastric cancer in all subgroups. Male, older age, obesity, diabetes mellitus (DM), a salty and spicy diet, and Helicobacter pylori (H. pylori) were significantly associated with precancerous conditions. However, risk factors related to precancerous conditions were different according to age and sex. In <40 years, H. pylori was the only risk factor related to precancerous conditions, whereas DM with a salty and spicy diet were additional risk factors in ≥40 years. In female individuals, obesity was significant risk factor for precancerous conditions as well as H. pylori infection.AG and IM are independent risk factors for gastric cancer. To prevent gastric cancer, H. pylori eradication may be more useful in <40 years, whereas additional factors such as DM, obesity, salty and spicy diet may be important in female or ≥40 years.

Increased Risk of Advanced Colorectal Neoplasia Among Korean Men With Metabolic Abnormality and Obesity

BACKGROUND & AIMS

Obesity and metabolic abnormality are risk factors for colorectal cancer and adenoma. We evaluated the risk of advanced colorectal neoplasm (AN) according to metabolic status and obesity in Koreans.

METHODS

We performed a retrospective cross-sectional study of 70,428 individuals in Korea who underwent colonoscopy and whose metabolic state and body mass index were examined, from 2003 through 2012, at Kangbuk Samsung Hospital in Korea. We calculated odds ratios (ORs) for AN in people who were metabolically healthy but obese, people with metabolic abnormality who were not obese, and people with metabolic abnormality who were obese. The reference group was metabolically healthy nonobese peoples. AN was defined as adenoma ≥10 mm in diameter, adenoma with any component of villous histology, high-grade dysplasia, or invasive cancer.

RESULTS

No increased risk of AN was observed in the metabolically healthy but obese (OR, 0.99; 95% confidence interval [CI], 0.67-1.46; P = .825) and metabolic abnormality who were not obese groups (OR, 1.01; 95% CI, 0.85-1.21; P = .765). In contrast, risk of AN was increased in the metabolic abnormality who were obese group (OR, 1.33; 95% CI, 1.12-1.58; P = .006). In men, risk of AN showed a greater increase in the metabolic abnormality who were obese group (OR, 1.48; 95% CI, 1.20-1.83; P = .001). This association was not observed in women (OR, 1.21; 95% CI, 0.84-1.75; P = .476).

CONCLUSIONS

Men with 1 or more metabolic abnormality and obesity are at increased risk for AN.

To assess the association between vertebral marrow fat content and colorectal adenoma in postmenopausal women using magnetic resonance spectroscopy

BACKGROUND

Although lower bone mineral density (BMD) is considered to have an increased risk for colorectal adenoma, no association between marrow fat content and colorectal adenoma has been elucidated yet.

PURPOSE

To evaluate the relationship between marrow fat fraction (MFF) and the presence of colorectal adenoma in postmenopausal women using magnetic resonance spectroscopy (MRS).

MATERIAL AND METHODS

We performed a cross-sectional observational study on 152 postmenopausal patients with colorectal adenoma and 100 matched control subjects who underwent screening colonoscopy, biochemical measurements, dual-energy X-ray absorptiometry, and MRS. Logistic regression models were performed to assess the relationships among BMD, MFF, and colorectal adenoma.

RESULTS

With univariate analysis, marrow fat accumulation was higher and BMD values were lower in patients with colorectal adenoma compared with those in controls. After adjustment for potential confounders including demographics, health history, blood lipid levels, indexes of glucose metabolism, and validated measures of diet and physical activity, MFF was significantly positively associated with colorectal adenoma (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.10-2.46; P = 0.008). Vertebral BMD, but not total hip and femoral neck BMD, was inversely related with colorectal adenoma (OR, 0.62; 95% CI, 0.14-0.89; P = 0.027). Additionally, MFF was associated with adenoma number, size, and high-risk adenoma (all P < 0.01). MFF was found to be an independent risk factor of a high-risk colorectal adenoma (OR, 2.08; 95% CI, 1.24-3.60; P = 0.019).

CONCLUSION

Marrow fat accumulation is highly associated with colorectal adenoma, particularly high-risk adenoma, in postmenopausal women.

Does the Presence of Endometrial Polyp Predict Colorectal Polyp?

INTRODUCTION

Endometrial polyps (EPs) and colorectal polyps (CPs) are common disorders and the incidence of both increase rapidly with aging. CPs are focal lesions and incidence increases with age.

AIM

In this study, we aimed to analyze retrospectively the relationship between the EPs and CPs sharing similar clinical and genetic factors in their etiopathogenesis.

MATERIALS AND METHODS

This study was retrospectively performed between 2010 and 2013 and it included patients diagnosed to have eEPs. The study group and the control group consisted of patients who were diagnosed with or without EPs and who underwent colonoscopy at the same period.

RESULTS

The study group was formed by 57 patients with diagnosis of EP who underwent colonoscopy during the same period. The control group consisted of 71 patients without EP examined with colonoscopy. Among 128 patients assessed in this study, 24 were diagnosed with CPs, all of which were adenomatous polyps smaller than 1cm. No hyperplastic or inflammatory polyps were diagnosed. While 18 of 57 patients with EPs had CPs, 6 of 71 control subjects had CPs. Hence, the risk of having CP was 5 times greater in patients with EP compared to those without (P < 0.05).

CONCLUSION

The present study demonstrated that the prevalence of CPs increased significantly in postmenopausal patients with EPs. Recommending colonoscopy to these patients irrespective of age may be beneficial for detecting more CPs and preventing colorectal cancer.

Adiponectin and colorectal cancer

Colorectal cancer is an obesity-related malignancy. Adiponectin is an adipokine produced exclusively by adipose tissue, and its concentration in the serum is reduced in obesity. A low serum level of adiponectin is associated with an increased risk of various types of malignancies including colorectal cancer. These facts suggest that the epidemiological link between obesity and cancer may have a significant association with adiponectin. Although numerous studies of colorectal cancer have been reported, the results are conflicting about the anti-cancer effect of adiponectin, and how adiponectin affects carcinogenesis or cancer development remains controversial. Because adiponectin has multiple systemic effects and exists as a high serum concentration protein, the main role of adiponectin should be regulation of homeostasis, and it would not likely act as an anti-cancerous hormone. However, as epidemiological evidence shows, a low adiponectin level may be a basic risk factor for colorectal cancer. We speculate that when the colonic epithelium is stimulated or damaged by another carcinogen under the condition of a low adiponectin level, carcinogenesis is promoted and cancer development is facilitated. In this report, we summarize recent findings of the correlation between adiponectin and colorectal cancer and investigate the effect of adiponectin on colorectal cancer.

Obesity-associated cancer: an immunological perspective

Epidemiological studies have established an association between obesity, insulin resistance, type 2 diabetes and a number of cancer types. Research has focused predominantly on altered endocrine factors, growth factors and signalling pathways, with little known in man about the immune involvement in the relevant pathophysiological processes. Moreover, in an era of exciting new breakthroughs in cancer immunotherapy, there is also a need to study the safety and efficacy of immunotherapeutics in the complex setting of inflammatory-driven obesity-associated cancer. This review addresses key immune cell subsets underpinning obesity-associated inflammation and describes how such immune compartments might be targeted to prevent and treat obesity-associated cancer. We propose that the modulation, metabolism, migration and abundance of pro- and anti-inflammatory cells and tumour-specific T cells might be therapeutically altered to both restore immune balance, alleviating pathological inflammation, and to improve anti-tumour immune responses in obesity-associated cancer.

[Role of Gastroenterologists in Management of Obesity]

Obesity is a serious disorder that increases morbidity and mortality. Primary intervention with life style modification and medication is not always effective for obese patients. Endoscopic management of obesity may be a less invasive, more cost-effective, and relatively safer option than bariatric surgery. Moreover, therapeutic endoscopy is considered to be the primary modality for managing complications that occur after bariatric surgery. In the near future, role of gastroenterologists will be more important in the management of obesity and its related problems.

Combination of Triple Therapy and Chronic PPI Use May Decrease Risk of Colonic Adenomatous Polyps in Helicobacter pylori Infection

Aim. The aim of the paper is to determine association between H. pylori and colonic adenomatous polyps and to explore whether treatment or chronic PPI use can mitigate this risk. Methods. This case-control study included 943 patients who had H. pylori testing and underwent colonoscopy. Presence of polyps was the outcome of interest, whereas age, sex, race, H. pylori infection, triple therapy, and chronic PPI use were independent variables. Multivariate regression analysis was used to calculate odds ratios at 95% confidence intervals. This study was approved by the New York Medical College Institutional Review Board. Results. H. pylori was associated with increased odds of colonic adenomatous polyps (adjusted OR 1.43, 95% CI 1.04–1.77), with stronger association among patients older than 50 (OR 1.65, 95% CI 1.18–2.33). Triple therapy (OR 0.69, 95% CI 0.44–1.07) or chronic PPI use (OR 0.69, 95% CI 0.43–1.09) decreased odds of polyp formation. Analysis revealed a statistically significant reduction in patients who received both triple therapy and chronic PPI, lowering the odds by 60% (adjusted OR 0.43, 95% CI 0.27–0.67). Conclusion. There is increased risk of colonic adenomatous polyps among H. pylori-infected patients. Triple therapy or chronic PPI use may mitigate this risk, with further reduction when these two interventions are combined.

Visceral adiposity and colorectal adenomas: dose-response meta-analysis of observational studies

BACKGROUND

Obesity-related hormonal and metabolic perturbations implicated in colorectal carcinogenesis are mainly driven by visceral adipose tissue (VAT) rather than subcutaneous adipose tissue (SAT). Yet, most epidemiologic studies have examined the relationship between excess adiposity and colorectal neoplasia using body mass index (BMI) and waist circumference (WC). Due to the inability of BMI and WC to distinguish VAT from SAT, they are likely to have underestimated the true association.

PATIENTS AND METHODS

We conducted a dose-response meta-analysis to summarize the relationships between VAT and colorectal adenomas and to examine the value of VAT as an independent risk factor beyond BMI, WC, and SAT. PubMed and Embase were searched through September 2014 to identify relevant observational studies. The summary odds ratio (OR) 95% confidence interval (CI) were estimated using a random-effects model.

RESULTS

In linear dose-response meta-analysis, the summary OR for each 25 cm(2) increase in VAT area was 1.13 (95% CI 1.05-1.21; I(2) = 62%; 6 studies; 2776 cases; range of VAT area = 30-228 cm(2)). The dose-response curve suggested no evidence of nonlinearity (Pnon-linearity = 0.37). In meta-analysis comparing the highest versus lowest category of VAT based on 12 studies, a positive association between VAT and adenomas remained statistically significant even after adjustment for BMI, WC, and SAT. In contrast, adjustment for VAT substantially attenuated associations of BMI, WC, and SAT with adenomas. Across the studies, VAT was more strongly associated with advanced adenomas than nonadvanced adenomas.

CONCLUSIONS

VAT may be the underlying mediator of the observed associations of BMI and WC with adenomas, increasing adenoma risk continuously over a wide range of VAT area. Considering that the joint use of BMI and WC better captures VAT than the use of either one, clinicians are recommended to use both BMI and WC to identify those at high risk for colorectal neoplasia.

Racial differences in obesity measures and risk of colorectal adenomas in a large screening population

Obesity is an important risk factor for colorectal neoplasia; however, little research exists on racial differences in obesity measures [body mass index (BMI), waist circumference (WC), and waist-hip-ratio (WHR)] associated with adenoma. We used data from the Diet and Health Studies, Phases III-V to examine differences in the contribution of obesity measures to adenoma risk by race. The sample consisted of 2184 patients (1806 white, 378 African American) undergoing outpatient colonoscopy for average risk screening. Covariates included demographics, health history, and validated measures of diet and physical activity. Among whites, BMI [overweight: odds ratio (OR) = 1.31, 95% confidence interval (CI), 1.00-1.71; obese: OR = 1.89, 95% CI, 1.41-2.56), WC (OR = 1.47, 95% CI, 1.09-1.99), and WHR (OR = 1.60, 95% CI, 1.24-2.06) were associated with adenomas. BMI was not associated with adenomas in African Americans. Although the CIs were wide, the point estimates for WHR (OR = 1.07, 95% CI, 0.51-2.22) and WC (OR = 1.04, 95% CI, 0.56-1.92) were slightly elevated above the null. BMI was associated with adenomas only among whites, whereas WHR and WC appeared to be important risk factors among both races. Racial differences in adenoma risk may be due to differences in body shape and weight and/or fat distribution.

Pulse-wave velocity, the ankle-brachial index, and the visceral fat area are highly associated with colorectal adenoma

BACKGROUND

Although both colorectal neoplasms and atherosclerosis may be induced by visceral fat accumulation, no association between these factors has yet been elucidated.

METHODS

Among Japanese participants in our colonoscopic screening and annual surveillance programs, asymptomatic subjects were investigated. Visceral fat area was measured by computed tomography, and the ankle-brachial index and pulse-wave velocity (markers of systemic atherosclerosis) were also estimated. Colorectal findings during screening were investigated in association with these parameters.

RESULTS

Nine hundred and seven subjects (males: 71.9%; mean age: 57.3±8.7 years) were enrolled. Colorectal adenomas were identified during colorectal screening of 407 subjects (44.9%). The prevalence of all colorectal adenoma and advanced neoplasia increased with an elevated pulse-wave velocity from 32.2% (advanced neoplasia, 2.6) to 62.1% (8.4%) in higher quartiles (p<0.001 and p=0.003). The risk of advanced neoplasia was higher in subjects with an abnormal ankle-brachial index (33% vs. 4.6%, p<0.001). Upon multivariate analysis, visceral fat area and pulse-wave velocity were associated with all adenoma, and the ankle-brachial index with advanced neoplasia.

CONCLUSIONS

The risk of colorectal adenoma was strongly associated with visceral fat area and markers of atherosclerosis. Colorectal adenoma and atherosclerosis may share a common pathogenesis and the same populations are at high-risk.

Conditional knockout of the leptin receptor in the colonic epithelium revealed the local effects of leptin receptor signaling in the progression of colonic tumors in mice

Leptin, secreted by the adipose tissue and known to be related to obesity, is considered to be involved in the onset and progression of colorectal cancer. However, the exact role of leptin in colorectal carcinogenesis is still unclear, as several controversial reports have been published on the various systemic effects of leptin. The aim of this study was to clarify the local and precise roles of leptin receptor (LEPR)-mediated signaling in colonic carcinogenesis using intestinal epithelium-specific LEPRb conditional knockout (cKO) mice. We produced and used colonic epithelium-specific LEPRb cKO mice to investigate the carcinogen-induced formation of aberrant crypt foci (ACF) and tumors in the colon, using their littermates as control. There were no differences in the body weight or systemic condition between the control and cKO mice. The tumor sizes and number of large-sized tumors were significantly lower in the cKO mice as compared with those in the control mice. On the other hand, there was no significant difference in the proliferative activity of the normal colonic epithelial cells or ACF formation between the control and cKO mice. In the control mice, marked increase of the LEPRb expression level was observed in the colonic tumors as compared with that in the normal epithelium; furthermore, signal transducer and activator of transcription (STAT3) was activated in the tumor cells. These findings suggest that STAT3 is one of the important molecules downstream of LEPRb, and LEPRb/STAT3 signaling controls tumor cell proliferation. We demonstrated the importance of local/regional LEPR-mediated signaling in colorectal carcinogenesis.

Republished: obesity and colorectal cancer

Excess body weight, as defined by the body mass index (BMI), has been associated with several diseases and includes subjects who are overweight (BMI≥25-29.9 kg/m(2)) or obese (BMI≥30 kg/m(2)). Overweight and obesity constitute the fifth leading risk for overall mortality, accounting for at least 2.8 million adult deaths each year. In addition around 11% of colorectal cancer (CRC) cases have been attributed to overweight and obesity in Europe. Epidemiological data suggest that obesity is associated with a 30-70% increased risk of colon cancer in men, whereas the association is less consistent in women. Similar trends exist for colorectal adenoma, although the risk appears lower. Visceral fat, or abdominal obesity, seems to be of greater concern than subcutaneous fat obesity, and any 1 kg/m(2) increase in BMI confers additional risk (HR 1.03). Obesity might be associated with worse cancer outcomes, such as recurrence of the primary cancer or mortality. Several factors, including reduced sensitivity to antiangiogenic-therapeutic regimens, might explain these differences. Except for wound infection, obesity has no significant impact on surgical procedures. The underlying mechanisms linking obesity to CRC are still a matter of debate, but metabolic syndrome, insulin resistance and modifications in levels of adipocytokines seem to be of great importance. Other biological factors such as the gut microbita or bile acids are emerging. Many questions still remain unanswered: should preventive strategies specifically target obese patients? Is the risk of cancer great enough to propose prophylactic bariatric surgery in certain patients with obesity?

Visceral abdominal fat measured by computed tomography is associated with an increased risk of colorectal adenoma

We investigated whether visceral adipose tissue (VAT) measured by computed tomography (CT) is a risk factor for colorectal adenoma. For a total of 1,328 patients (857 without adenoma, 471 with colorectal adenoma) undergoing colonoscopy and CT, associations between colorectal adenoma and body mass index (BMI), VAT area and subcutaneous adipose tissue (SAT) were assessed using odds ratios (ORs) with 95% confidence intervals (CIs) adjusted for age, sex, family history, smoking, alcohol intake, diabetes mellitus, aspirin use and nonsteroidal anti-inflammatory drug use. Multivariate analysis showed that colorectal adenoma was marginally associated (p=0.06) with BMI, but not with SAT, while it was significantly associated with VAT and the VAT to SAT ratio (VAT/SAT) for both categorical data and trend (p<0.05). When the obesity indices were considered simultaneously, colorectal adenoma remained significantly associated with VAT and VAT/SAT (p<0.05), but not BMI and SAT. In patients with colorectal adenoma, the adjusted OR for the highest quartiles of VAT and VAT/SAT was 1.90 (95% CI 1.16-3.13) and 2.25 (95% CI 1.49-3.41), respectively, compared to the lowest quartiles. Only VAT area was significantly associated with colorectal adenoma in both men and women (p<0.05). Proximal, multiple and advanced adenomas had significantly higher VAT areas (p<0.05) than distal, solitary and nonadvanced adenomas. Our findings implicate abdominal VAT in the development and progression of colorectal adenoma, and it was better obesity index for colorectal adenoma than BMI in both sexes.