An association between colonic adenoma and abdominal obesity: a cross-sectional study

Overweight and obesity are associated with colorectal neoplasia in an Australian outpatient population

Colorectal cancer is a major cause of cancer-related deaths within the Australian population. Colonoscopy and polypectomy represent effective forms of prevention. Factors such as diabetes, hypertension and dyslipidaemia have been linked to adenoma development across a range of ethnicities, however there are limited data from the Australian population. This study investigates established and potential risk factors for early colorectal neoplasia in an Australian population. This was a prospective, observational case-control study in subjects aged 20-85 years, referred for outpatient colonoscopy. Clinical, anthropometric, and biochemical variables were collected at baseline. Polyps were classified as conventional adenomas or sessile serrated lesions, and correlated with clinical and biochemical variables. The study included 357 subjects, median age 55 years (IQR: 43.0-64.0), and 52.9% were female. 41.7% had metabolic syndrome. Multiple positive associations were observed in those over 40 years and with a BMI ≥ 25, including any polyp (aOR: 2.26; 95%CI: 1.22-4.18); adenoma (aOR: 2.64; 95%CI: 1.31-5.31); and, non-advanced adenoma (aOR: 2.66; 95%CI: 1.25-5.68). Our study demonstrates that elevated BMI is an independent risk factor for colorectal neoplasia in Australians undergoing colonoscopy. Further efforts should be focused on both diet and weight optimization in the general population given these findings and the recent national statistics indicating that almost two-thirds of the population are either overweight or obese.

Risk prediction of advanced colorectal neoplasia among diabetic patients: A derivation and validation study

Background and Aim

Colorectal cancer (CRC) is the third most common cancer in the world. This study devises and validates a clinical scoring system for risk prediction of advanced colorectal neoplasia (ACN) to guide colonoscopy evaluation among diabetic patients.

Methods

We identified 55 964 diabetic patients who received colonoscopies from a large database in a Chinese population (2008-2018). We recruited a derivation cohort based on random sampling. The risk factors of CRC evaluated by univariate analysis were examined for ACN, defined as advanced adenoma, CRC, or any combination thereof using binary logistic regression analysis. We used the adjusted odds ratios (aORs) for independent risk factors to devise a risk score, ranging from 0 to 6: 0-4 "average risk" (AR) and 5-6 "high risk" (HR). The other subjects acted as an independent validation cohort.

Results

The prevalence of ACN in both the derivation and validation cohorts was 2.0%. Using the scoring system constructed, 78.5% and 21.5% of patients in the validation cohort were classified as AR and HR, respectively. The prevalence of ACN in the AR and HR groups was 1.5% and 4.1%, respectively. Individuals in the HR group had a 2.78-fold increased prevalence of ACN than the AR group. The concordance (c-) statistics was 0.70, implying a good discriminatory capability of the risk score to stratify high-risk individuals who should consider colonoscopy.

Conclusion

The clinical risk scoring system based on age, gender, smoking, presence of hypertension, and use of aspirin is useful for ACN risk prediction among diabetic patients.

Association between visceral obesity, metformin use, and recurrence risk in early-stage colorectal cancer

We sought to investigate the association between visceral obesity with disease recurrence and survival in early-stage colorectal cancer (CRC) patients. We also wanted to examine if such an association, if exists, is influenced by metformin use. Stage I/II CRC adenocarcinoma patients treated surgically were identified. L3 level CT VFI (visceral fat index) was used as a metric of visceral obesity and was calculated as the proportion of total fat area composed of visceral fat. N = 492. 53% were males, 90% were Caucasians, 35% had stage I disease, and 14% used metformin. 20.3% patients developed a recurrence over a median follow-up of 56 months. VFI was associated with both RFS and OS in a multivariate model, but not BMI. The final multivariate model for RFS included an interaction term for VFI and metformin (p = 0.04). Confirming this result, subgroup analysis showed an increasing VFI was associated with a poor RFS (p = 0.002), and OS (p < 0.001) in metformin non-users only and metformin use was associated with a better RFS only in the top VFI tertile (p = 0.01). Visceral obesity, but not BMI, is associated with recurrence risk and poorer survival in stage I/II CRC. Interestingly, this association is influenced by metformin use.

Changing Colorectal Cancer Trends in Asians: Epidemiology and Risk Factors

Once an infrequent disease in parts of Asia, the rate of colorectal cancer in recent decades appears to be steadily increasing. Colorectal cancer represents one of the most important causes of cancer mortality worldwide, including in many regions in Asia. Rapid changes in socioeconomic and lifestyle habits have been attributed to the notable increase in the incidence of colorectal cancers in many Asian countries. Through published data from the International Agency for Cancer Research (IARC), we utilized available continuous data to determine which Asian nations had a rise in colorectal cancer rates. We found that East and South East Asian countries had a significant rise in colorectal cancer rates. Subsequently, we summarized here the known genetics and environmental risk factors for colorectal cancer among populations in this region as well as approaches to screening and early detection that have been considered across various countries in the region.

Beyond colonoscopy: Physical activity as a viable adjunct to prevent colorectal cancer

Colorectal cancer (CRC) is a common cancer with an increasing incidence worldwide. The implementation of a mass screening program has been proven effective in reducing the global burden of CRC, but its effectiveness is not ideal and some metabolic derangements and lifestyle factors were reported to be attributable for such a deficit. Implementing positive lifestyle intervention as primary prevention therefore becomes critical because colorectal carcinogenesis can be promoted by several lifestyle factors, such as a lack of physical activity. Herein, we review the current evidence on the association and possible mechanisms between physical activity and CRC carcinogenesis. In addition, since CRC prevention heavily relies on resection of precancerous polyps and subsequent surveillance by colonoscopy, this review will also explore the impact of physical activity on populations with different colorectal polyp risks and its potential adjunct role in altering surveillance outcomes.

Prevalence of Colorectal Polyps Based on Cardiorespiratory Fitness, Muscle Strength, Health Behavior, and Abdominal Obesity in Asymptomatic Elderly

Colorectal polyps are precursor lesions of colorectal cancer and are known to be associated with obesity, low physical activity, and unhealthy behavior. This cross-sectional study analyzed the prevalence of colorectal polyps based on cardiorespiratory fitness (CRF), muscle strength, and health behavior in older adults. Participants were asymptomatic and included 1024 men and 472 women aged 65-80 years who visited the health care center. Colonoscopy was performed under conscious sedation, and cardiorespiratory fitness was measured as the maximum oxygen uptake using gas analysis. Muscle strength was determined using isokinetic equipment, and physical activity, alcohol consumption, and smoking status were investigated using questionnaires. Waist circumference was measured at the thickest part of the middle of the abdomen. Logistic regression analysis was used to calculate the prevalence of colorectal polyps using odds ratios (ORs) based on the variables. The incidence of colorectal polyps was 65.2% in men and 48.5% in women. The ORs of colorectal polyps for obesity were 1.151 (95% confidence interval [CI], 1.010-2.291) and 1.178 (95% CI, 1.015-2.612) in men and women, respectively. The OR for colorectal polyps in male current smokers was 1.884. The ORs for low CRF were 1.985 and 1.841 in men and women, respectively, compared with high CRF. The prevalence of polyps increased with low muscle strength (men's OR 1.343 women's OR 1.440) and physical activity in both men (OR 1.693) and women (OR 1.861). In conclusion, lower CRF and muscle strength were associated with an increased prevalence of colorectal polyps in men and women. In both sexes, high waist circumference and low physical activity increased the prevalence of colorectal polyps.

Increasing changes in visceral adiposity is associated with higher risk for colorectal adenoma: Multilevel analysis in a prospective cohort

BACKGROUND AND AIM

While many studies demonstrated an association between visceral adiposity and colorectal adenoma (CRA), the effect of longitudinal changes in body fat composition on CRA is unclear. We investigated the longitudinal association between changes in visceral adiposity and CRA occurrence.

METHODS

Between 2006 and 2018, 732 (62.8%) of the 1165 subjects in a prospective cohort voluntarily underwent follow-up abdominal fat computed tomography and colonoscopy. We defined incident and recurrent CRA as adenoma detected at follow-up colonoscopy from negative and positive adenoma at baseline colonoscopy, respectively. Multilevel survival analysis examined the longitudinal association between changes in visceral fat and CRA.

RESULTS

During a median follow-up of 7.4 years, 400 (54.6%) subjects developed CRA. In multivariable analysis, increasing changes in visceral adipose tissue (VAT) area were associated with higher risk of incident adenoma (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.00-1.46 for change per 10 cm2 increase; HR 1.79, 95% CI 1.08-2.97 for highest vs lowest quartile, P values for trend = 0.045). Likewise, increasing changes in VAT area were independently associated with a higher risk of recurrent adenoma (HR 1.35, 95% CI 1.13-1.62 for change per 10 cm2 increase; HR 1.62, 95% CI 1.04-2.52 for highest vs lowest quartile, P values for trend = 0.001). Changes in subcutaneous adipose tissue area were not independently associated with CRA.

CONCLUSION

Increasing changes in VAT area were longitudinally associated with a higher risk of incident and recurrent CRA, independent of risk factors, suggesting that visceral adiposity may be an important target in CRA prevention.

Risk factors including night shift work of colorectal polyp

Background

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

Methods

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

Results

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

Conclusions

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

Does the withdrawal time affect adenoma detection in non-screening colonoscopies?

AIMS

There are no studies looking at the relationship between colonoscopy withdrawal time (CWT) and adenoma detection rate (ADR) in non-screening patients. Our aim is to explore the relationship between CWT and ADR, particularly in the proximal colon where colonoscopy is shown to be less protective for the development of cancers.

METHODS

This is a retrospective study during November 2015 to December 2016 of non-screening colonoscopies done at a large teaching hospital. Incomplete and therapeutic procedures were excluded. The 39 endoscopists included were 15 gastroenterologists, 10 colorectal surgeons and 14 trainee colonoscopists. CWT was calculated by reviewing caecal intubation and rectal retroflexion images.

RESULTS

783 colonoscopies were included, with mean patient age of 58.51 years (SD 15.5). The mean ADR was 21.45% in the study. The CWT could be calculated for 62.83% of the cases (n=492). 80% (393) of colonoscopies had CWT of ≥6 min. Mean CWT was 9.15 min (SD 4.4). The ADR positively correlated with longer CWT (r=0.31, p=0.0001). The ADR was significantly higher when CWT was ≥8 min compared with CWT <6 min or CWT of 6-8 min (p=0.0001). More polyps were detected in the proximal colon when CWT ≥8 min (p=0.078). Mean CWT of gastroenterologists was 9.8 min (SD 4.5), similar to the trainee group (10.3 min, SD 3.8), while mean CWT for colorectal surgeons was 5.7 min (SD 3.2). The ADR for gastroenterologists was 25.9% versus 17.5% for colorectal surgeons and 17.8% for trainees.

CONCLUSIONS

There is a moderately strong positive correlation between longer CWT and ADR in non-screening colonoscopies. CWT can differ between different endoscopists. Meticulous colonoscopy withdrawal may improve polyp detection in the proximal colon.

Abdominal Obesity is More Predictive of Advanced Colorectal Neoplasia Risk Than Overall Obesity in Men: A Cross-sectional Study

GOALS

We aimed to ascertain whether waist circumference (WC) is associated with risk of colorectal neoplasia (CRN), independent of body mass index (BMI).

BACKGROUND

Although several studies have reported the association between abdominal obesity, measured by WC, and CRN, it remains unclear whether their association is biased by BMI.

STUDY

A cross-sectional study was performed on 154,552 asymptomatic examinees who underwent colonoscopy for a health check-up.

RESULTS

The mean age was 42.6 years, and the proportion of males was 65.2%. The prevalence rate of CRN in subjects in WC quartiles 1, 2, 3, and 4 was 15.6%, 18.1%, 20.4%, and 22.0% among men and 7.8%, 9.4%, 12.2%, and 15.8% among women, respectively. WC and BMI were independent risk factors for overall CRN and nonadvanced CRN in both men and women. In men, the association of BMI with advanced CRN was attenuated to null after adjusting for WC [Q2, Q3, and Q4 vs. Q1; odds ratios (95% confidence intervals), 0.93 (0.79-1.10), 0.85 (0.71-1.03), and 0.99 (0.80-1.22), respectively; Ptrend=0.822], whereas the association of WC with advanced CRN significantly persisted even after adjusting for BMI [Q2, Q3, and Q4 vs. Q1; 1.20 (1.02-1.42), 1.45 (1.20-1.75), and 1.64 (1.32-2.04), respectively; Ptrend<0.001]. In women, neither WC nor BMI was associated with the risk of advanced CRN.

CONCLUSIONS

Abdominal obesity is associated with an increased risk of advanced CRN, independent of overall obesity (BMI) in men. Our findings suggest that abdominal obesity is more strongly predictive of advanced CRN than overall obesity in men.

Alcohol consumption is associated with the risk of developing colorectal neoplasia: Propensity score matching analysis

Although alcohol intake is known to be associated with the development of colorectal cancer, the effect of alcohol consumption on the development of colorectal neoplasm (CRN) is unclear. We performed a retrospective cohort analysis with 1 to 1 propensity score matching in a single center of Korea. Among 1,448 patients who underwent index and surveillance colonoscopy, 210 matched pairs were analyzed. The 5-year cumulative occurrence of overall CRN after index colonoscopy was higher in the significant alcohol consumption group (defined as alcohol consumption more than 30 g/day in men and 20 g/day in women) (vs. without significant alcohol consumption group) (40% vs. 27.6%, p = 0.004). Significant alcohol consumption increased the development of overall CRN (adjusted hazard ratio [aHR]: 1.86, 95% confidence interval [CI]: 1.28-2.70, p = 0.001) at surveillance colonoscopy. However, this effect was not valid on the development of advanced CRN. In subgroup analysis considering the risk classification of index colonoscopy, significant alcohol consumption increased the overall CRN development at surveillance colonoscopy in the normal group (patients with no detected adenoma in the index colonoscopy) (aHR: 1.90, 95% CI: 1.16-3.13, p = 0.01). Alcohol consumption habits should be considered in optimizing time intervals of surveillance colonoscopy.

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.

A modified colorectal screening score for prediction of advanced neoplasia: A prospective study of 5744 subjects

BACKGROUND AND AIM

We validated a modified risk algorithm based on the Asia-Pacific Colorectal Screening (APCS) score that included body mass index (BMI) for prediction of advanced neoplasia.

METHODS

Among 5744 Chinese asymptomatic screening participants undergoing a colonoscopy in Hong Kong from 2008 to 2012, a random sample of 3829 participants acted as the derivation cohort. The odds ratios for significant risk factors identified by binary logistic regression analysis were used to build a scoring system ranging from 0 to 6, divided into "average risk" (AR): 0; "moderate risk" (MR): 1-2; and "high risk" (HR): 3-6. The other 1915 subjects formed a validation cohort, and the performance of the score was assessed.

RESULTS

The prevalence of advanced neoplasia in the derivation and validation cohorts was 5.4% and 6.0%, respectively (P = 0.395). Old age, male gender, family history of colorectal cancer, smoking, and BMI were significant predictors in multivariate regression analysis. A BMI cut-off at > 23 kg/m² had better predictive capability and lower number needed to screen than that of > 25 kg/m² . Utilizing the score developed, 8.4%, 57.4%, and 34.2% in the validation cohort were categorized as AR, MR, and HR, respectively. The corresponding prevalence of advanced neoplasia was 3.8%, 4.3%, and 9.3%. Subjects in the HR group had 2.48-fold increased prevalence of advanced neoplasia than the AR group. The c-statistics of the modified score had better discriminatory capability than that using predictors of APCS alone (c-statistics = 0.65 vs 0.60).

CONCLUSIONS

Incorporating BMI into the predictors of APCS score was found to improve risk prediction of advanced neoplasia and reduce colonoscopy resources.

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.

Gastrointestinal Complications of Obesity

Obesity usually is associated with morbidity related to diabetes mellitus and cardiovascular diseases. However, there are many gastrointestinal and hepatic diseases for which obesity is the direct cause (eg, nonalcoholic fatty liver disease) or is a significant risk factor, such as reflux esophagitis and gallstones. When obesity is a risk factor, it may interact with other mechanisms and result in earlier presentation or complicated diseases. There are increased odds ratios or relative risks of several gastrointestinal complications of obesity: gastroesophageal reflux disease, erosive esophagitis, Barrett's esophagus, esophageal adenocarcinoma, erosive gastritis, gastric cancer, diarrhea, colonic diverticular disease, polyps, cancer, liver disease including nonalcoholic fatty liver disease, cirrhosis, hepatocellular carcinoma, gallstones, acute pancreatitis, and pancreatic cancer. Gastroenterologists are uniquely poised to participate in the multidisciplinary management of obesity as physicians caring for people with obesity-related diseases, in addition to their expertise in nutrition and endoscopic interventions.

Background Colonic 18F-Fluoro-2-Deoxy-D-Glucose Uptake on Positron Emission Tomography Is Associated with the Presence of Colorectal Adenoma

¹⁸F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) scan is used to evaluate various kinds of tumors. While most studies on PET findings of the colon focus on the colonic uptake pattern, studies regarding background colonic uptake on PET scan are rare. The purpose of this study was to identify the association between the background colonic uptake and the presence of colorectal adenoma (CRA), which is a frequent precancerous lesion. We retrospectively reviewed the medical records of 241 patients with gynecologic malignancy who had received PET or PET/computed tomography (CT) scan and colonoscopy at the same period as a baseline evaluation. Background colonic ¹⁸F-FDG uptake was visually graded and the maximal standardized uptake values (SUV_max) of 7 different bowel segments were averaged. In univariate analysis, older age at diagnosis (≥ 50 years, p = 0.034), overweight (BMI ≥ 23 kg/m², p = 0.010), hypercholesterolemia (≥ 200 mg/dL, p = 0.027), and high grade background colonic uptake (p = 0.009) were positively associated with the prevalence of CRA. By multiple logistic regression, high grade background colonic uptake was independently predictive of CRA (odds ratio = 2.25, p = 0.021). The proportion of CRA patients significantly increased as background colonic uptake grade increased from 1 to 4 (trend p = 0.015). Out of the 138 patients who underwent PET/CT, the proportion of CRA patients in the group with high SUV_max (> 2.25) was significantly higher than in the low SUV_max group (27.5% vs. 11.6%, p = 0.031). In conclusion, high grade of background colonic ¹⁸F-FDG uptake is significantly associated with the prevalence of CRA.

Validation of a risk prediction score for proximal neoplasia in colorectal cancer screening: a prospective colonoscopy study

This study developed a clinical scoring system to predict the risks of PN among screening participants for colorectal cancer. We recruited 5,789 Chinese asymptomatic screening participants who received colonoscopy in Hong Kong (2008-2014). From random sampling of 2,000 participants, the independent risk factors were evaluated for PN using binary regression analysis. The odds ratios for significant risk factors were used to develop a scoring system, with scores stratified into 'average risk' (AR):0-2 and 'high risk' (HR):3-5. The other 3,789 subjects formed an independent validation cohort. Each participant received a score calculated based on their risk factors. The performance of the scoring system was evaluated. The proportion of PN in the derivation and validation cohorts was 12.6% and 12.9%, respectively. Based on age, gender, family history, body mass index and self-reported ischaemic heart disease, 85.0% and 15.0% in the validation cohort were classified as AR and HR, respectively. Their prevalence of PN was 12.0% and 18.1%, respectively. Participants in the HR group had 1.51-fold (95% CI = 1.24-1.84, p < 0.001) higher risk of PN than the AR group. The overall c-statistics of the prediction model was 0.71(0.02). The scoring system is useful in predicting the risk of PN to prioritize patients for colonoscopy.

Right colon carcinoma infiltrating the alimentary limb in a patient with biliopancreatic diversion

Biliopancreatic diversion (BPD) has excellent results, with the average patient losing 60% to 80% of the excess weight in the first 2 years. However, the BPD works by malabsorption and malabsorptive problems may be experienced with the operation. Therefore, monitoring is necessary for life. In the recent literature there is some debate over the possibility that this technique can increase the risk of colon cancer secondary to the action of the unabsorbed food and bile acid on colonic mucosa. We report the case of a 42-year-old patient with a previous bariatric surgery (BPD with 50 cm common channel; 300 cm alimentary limb) who developed a very aggressive right colon cancer 6 years after the operation. We also review our series of 330 patients operated on during a 14-year period to try to answer if there is any relationship between BPD and colon cancer.

Colorectal adenoma is associated with coronary artery calcification in a Korean population

OBJECTIVE

Colorectal adenoma and coronary atherosclerosis have similar risk factors. The aim of this study was to investigate the association between colorectal adenoma and coronary artery calcification (CAC), which is used as a surrogate marker for coronary atherosclerosis.

METHODS

This is a cross-sectional study of 398 Koreans (290 males, mean age of 56.8 ± 8.1 years) who underwent CAC scoring by multi-slice computed tomography and colonoscopy on the same day as the screening examination. The CAC scores were divided into the following three categories according to severity: absent (CAC score = 0), mild (0 < CAC score ≤ 100), and moderate-to-severe CAC (CAC score > 100).

RESULTS

Colorectal adenoma was detected in 149 (37.4%) subjects and was significantly associated with a CAC score of >0 (OR = 1.66, 95% CI = 1.05-2.64, P = 0.032), including both mild (OR = 1.80, 95% CI = 1.06-3.03, P = 0.029) and moderate-to-severe CAC (OR = 1.95, 95% CI = 1.05-3.63, P = 0.035), in multivariate analysis after adjusting for age, gender and other risk factors. The proportion of subjects with colorectal adenoma and advanced adenoma progressively increased with increasing CAC score (colorectal adenoma 28.9%-54.1%, P for trend < 0.001; advanced adenoma 7.0%-16.4%, P for trend = 0.026).

CONCLUSION

Colorectal adenoma is related to coronary artery calcification independent of traditional risk factors for asymptomatic Koreans. The prevalence of advanced adenoma is more common in individuals with severe coronary atherosclerosis.

Body mass index and colon cancer screening: the road ahead

Screening for colorectal cancer (CRC) has been associated with a decreased incidence and mortality from CRC. However, patient adherence to screening is less than desirable and resources are limited even in developed countries. Better identification of individuals at a higher risk could result in improved screening efforts. Over the past few years, formulas have been developed to predict the likelihood of developing advanced colonic neoplasia in susceptible individuals but have yet to be utilized in mass screening practices. These models use a number of clinical factors that have been associated with colonic neoplasia including the body mass index (BMI). Advances in our understanding of the mechanisms by which obesity contributes to colonic neoplasia as well as clinical studies on this subject have proven the association between BMI and colonic neoplasia. However, there are still controversies on this subject as some studies have arrived at different conclusions on the influence of BMI by gender. Future studies should aim at resolving these discrepancies in order to improve the efficiency of screening strategies.

The association between coronary calcification and adenomatous polyps of colon in Korean adults

BACKGROUND AND OBJECTIVE

Adenomatous polyps of colon is a precancerous lesion. Many studies have shown that the adenomatous polyps of colon and cardiovascular disease share several common risk factors. This cross-sectional study aimed to investigate whether coronary calcification is associated with the adenomatous polyps of colon.

METHODS

Among 1637 Korean adults, we examined the association between coronary calcium score (CCS) as a measurement of coronary calcification and the presence of adenomatous polyps of colon via multi-detected row computed tomography (MDCT) and colonoscopy, respectively. CCS values were categorized as follows: 0, 1-17, 18-105, or≥106. The odds ratios (ORs) and 95% confidence intervals (CIs) for the presence of adenomatous polyps of colon were calculated across CCS groups.

RESULTS AND CONCLUSIONS

After adjusting for confounding variables, the adjusted ORs (95% CIs) for the presence of adenomatous polyps of colon in each of the four CCS groups were 1.00 (reference), 1.44 (0.91-2.33), 1.88 (1.15-3.01) and 3.61 (2.23-5.74). And higher CCS values were associated with multiple polyps (P≤0.001), villous histologic features or high-grade dysplasia (P=0.02), and advanced adenomatous polyps (P≤0.001). A higher level of CCS was found to be strongly and independently associated with the presence of adenomatous polyps of colon in Korean adults. This finding suggests that people at high risk for coronary atherosclerosis through MDCT should be considered for further evaluation of adenomatous polyps.

A validated tool to predict colorectal neoplasia and inform screening choice for asymptomatic subjects

OBJECTIVE

We aim to develop and validate a clinical scoring system to predict the risks of colorectal neoplasia to better inform screening participants and facilitate their screening test choice.

DESIGN

We recruited 5220 Chinese asymptomatic screening participants who underwent colonoscopy in Hong Kong during 2008-2012. From random sampling of 2000 participants, independent risk factors were evaluated for colorectal neoplasia, defined as adenoma, advanced neoplasia, colorectal cancer or any combination thereof using binary regression analysis. The ORs for significant risk factors were used to develop a scoring system ranging from 0 to 6: 0-2 'average risk' (AR) and 3-6 'high risk' (HR). The other 3220 screening participants prospectively enrolled between 2008 and 2012 for screening colonoscopy formed an independent validation cohort. The performance of the scoring system for predicting colorectal neoplasia was evaluated.

RESULTS

The prevalence of colorectal neoplasia in the derivation and validation cohorts was 31.4% and 30.8%, respectively. Using the scoring system developed, 78.9% and 21.1% in the validation cohort were classified as AR and HR, respectively. The prevalence of colorectal neoplasia in the AR and HR groups was 27.1% and 44.6%, respectively. The subjects in the HR group had 1.65-fold (95% CI 1.49 to 1.83) increased prevalence of colorectal neoplasia than the AR group.

CONCLUSIONS

The scoring system based on age, gender, smoking, family history, Body Mass Index and self-reported diabetes is useful in predicting the risk of colorectal neoplasia.

Prevalence and risk factors of asymptomatic colorectal polyps in taiwan

Purpose. To investigate the prevalence and risk factors of hyperplastic and adenomatous colorectal polyps in a Taiwanese general population. Methods. From January 2009 to December 2011, consecutive asymptomatic subjects undergoing a routine health check-up were evaluated by colonoscopy. The colorectal polyps were assessed, and medical history and demographic data were obtained from each patient. Logistic regression analysis was conducted to search the independent risk factors for asymptomatic hyperplastic and adenomatous colorectal polyps. Results. Of the 1899 asymptomatic subjects, the prevalences of hyperplastic polyps and adenomatous polyps were 11.1% and 16.1%, respectively. Multivariate analysis revealed that high body mass index (BMI > 25: OR, 1.32, 95% CI, 1.05-1.71) and current smoking (OR, 1.87, 95% CI, 1.42-2.71) were independent predictors for hyperplastic colorectal polyps. Age over 60 years old (OR, 3.49, 95% CI, 1.86-6.51), high body mass index (BMI > 25: OR, 1.75, 95% CI, 1.21-2.71), heavy alcohol consumption (OR, 2.01, 95% CI, 1.02-3.99), and current smoking (OR, 1.31, 95% CI, 1.04-1.58) were independent predictors for adenomatous colorectal polyps. Conclusion. High BMI and smoking are common risk factors for both adenomatous and hyperplastic polyps. Old age and alcohol consumption are additional risk factors for the development of adenomatous polyps.

Predictors of advanced colorectal neoplasia for colorectal cancer screening

BACKGROUND

The Asia-Pacific Colorectal Screening (APCS) score based on age, gender, family history, and smoking is useful to predict advanced colorectal neoplasia (ACN) in asymptomatic Asian subjects.

PURPOSE

To evaluate the factors in addition to those of APCS associated with ACN colonoscopic findings.

METHODS

Data from 5,220 asymptomatic subjects aged between 50 and 70 years who underwent screening colonoscopy in a community center between 2008 and 2012 were analyzed. One binary logistic regression analysis was conducted in 2013 with the presence of ACN or cancer as the outcome, controlling for APCS score, alcohol consumption, BMI, hypertension, and other chronic diseases as independent variables.

RESULTS

The average participant age was 57.7 years (SD=4.9) and 47.5% were men. Advanced neoplasms or cancers were identified at colonoscopy in 5.6% of all screening participants. From multivariate regression analysis, APCS score≥4 (adjusted OR [AOR]=1.74, 95% CI=1.34, 2.25, p<0.001); overweight (BMI=23-24.9, AOR=1.52, 95% CI=1.12, 2.07, p=0.007); obesity (BMI≥25, AOR=1.56, 95% CI=1.15, 2.10, p=0.004); hypertension (AOR=1.58, 95% CI=1.21, 2.06, p=0.001); and alcohol consumption (AOR=1.47, 95% CI=1.05, 2.06, p=0.025) were associated with ACN. The c-statistic of APCS score alone was 0.560 (95% CI=0.524, 0.595, p=0.001) and that of APCS score plus BMI, hypertension, and alcohol consumption was 0.613 (95% CI=0.578, 0.648, p<0.001).

CONCLUSIONS

Alcohol consumption, hypertension, and BMI are independent predictors of ACN, which could be incorporated into the APCS for prioritizing Asian asymptomatic subjects for colorectal cancer screening.

BMI and the risk of colorectal adenoma in African-Americans

OBJECTIVES

Obesity is associated with the activation of the molecular pathways that increase the risk of colorectal cancer. Increasing body mass index may accelerate the development of adenomatous polyps, the antecedent lesion of colorectal cancer. The aim of this study was to assess the BMI effect on the risk of colonic polyp and adenoma in African-American.

METHODS

The records of 923 patients who underwent colonoscopy were examined. Demographic and clinical data were collected before colonoscopy. Polyp and adenoma diagnosis were confirmed by pathology examinations.

RESULTS

Overall, 43% of the patients were male, median age was 57 years and 77% had BMI ≥ 25.0 kg/m(2) . The frequency of colorectal polyps and adenomas were 61 and 35%, respectively. BMI ≥ 25.0 (OR = 1.61, 95% CI = 1.14-2.26), smoking (OR = 1.61, 95% CI = 1.15-2.26) and history of colon polyps (OR = 1.64, 95% CI = 1.09-2.47) were associated with higher risk of colon polyp. BMI ≥ 25.0 (OR = 1.81, 95% CI = 1.24-2.62), age (OR = 1.04, 95% CI = 1.02-2.05 for each year), male gender (OR = 1.38, 95% CI = 1.02-1.86), and smoking (OR = 1.73, 95% CI = 1.23-2.42) were associated with higher risk of colon adenoma.

CONCLUSION

Male and overweight African-Americans are at higher risk of colorectal adenoma. The findings of this study could be applied for risk stratification and modifying the colorectal cancer prevention including screening guideline in African Americans.

Obesity, metabolic factors, and colorectal adenomas: a retrospective study in a racially diverse New York State Hospital

OBJECTIVE

We studied a racially diverse population and the relationship with colorectal adenomas (CA) further looking for risks related to BMI and metabolic factors.

DESIGNS

Seven hundred seventy-nine patients who underwent screening colonoscopies between 2007 and 2009 meeting exclusion criteria were included. To evaluate the association between race, BMI, and other metabolic factors with having one or more CA detected at colonoscopy, adjusted odds ratios and 95 % CI were estimated using unconditional logistic regression models.

OUTCOMES

CA were detected in 167 out of 779 (21.4 %) patients. Compared to Whites, Hispanics were less likely to have one or more adenomas detected during a screening colonoscopy (OR = 0.52, 95 % CI, 0.31-0.88; p = 0.01). There was no significant statistical difference between Blacks and Whites, or other races and Whites. There was an association between the presence of CA and smoking (OR = 1.57, 95 % CI, 1.02-2.43; p = 0.04).

CONCLUSION

Our results showed that Hispanics were less likely to have an adenoma detected during a screening colonoscopy than Whites. No statistical significant difference was found between patients with metabolic factors and the presence of colorectal adenoma.

Gastrointestinal morbidity in obesity

Obesity is a complex disease that results from increased energy intake and decreased energy expenditure. The gastrointestinal system plays a key role in the pathogenesis of obesity and facilitates caloric imbalance. Changes in gastrointestinal hormones and the inhibition of mechanisms that curtail caloric intake result in weight gain. It is not clear if the gastrointestinal role in obesity is a cause or an effect of this disease. Obesity is often associated with type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Obesity is also associated with gastrointestinal disorders, which are more frequent and present earlier than T2DM and CVD. Diseases such as gastroesophageal reflux disease (GERD), cholelithiasis, or nonalcoholic steatohepatitis are directly related to body weight and abdominal adiposity. Our objective is to assess the role of each gastrointestinal organ in obesity and the gastrointestinal morbidity resulting in those organs from the effects of obesity.

Obesity and colorectal adenomatous polyps: a cross-sectional study in Korean adults

OBJECTIVE

This study aimed to examine the association between obesity and the risk of colorectal adenomatous polyps.

DESIGN AND METHODS

The design of this study is a cross-sectional study. A total of 1,574 participants (818 males and 756 females), who had undergone colonoscopy for health examinations at the National Cancer Center hospital in South Korea from February to September 2009, were included in the analysis.

RESULTS

The prevalence of colorectal adenomatous polyps was 39.5% in males and 22.6% in females. In multiple logistic regression analysis, obesity (odds ratio [OR] = 1.69, 95% CI = 1.16-2.48) and abdominal obesity (OR = 1.59, 95% CI = 1.13-2.23) were significantly associated with an increased risk of colorectal adenomatous polyps in males, but not in females. In the subgroup analyses by age, obesity (OR = 2.27, 95% CI = 1.32-3.89), and abdominal obesity (OR = 1.76, 95% CI = 1.12-2.76) significantly increased a risk of colorectal adenomatous polyps in males aged <50 years, but not in males aged ≥50 years. However, interaction terms were not significant between obesity and gender (P = 0.397) and between obesity and age (P = 0.531) in the overall analyses.

CONCLUSION

Our findings should be explored in further research.

Association of gallbladder polyp with the risk of colorectal adenoma

Background/Aims

Gallbladder polyps and colorectal adenomas share many common risk factors; however, their association has never been studied. The aim of this study was to investigate this association in asymptomatic healthy subjects.

Methods

Consecutive asymptomatic subjects who underwent both screening colonoscopy and abdominal ultrasonography at Kyung Hee University Hospital in Gang Dong between July 2010 and April 2011 were prospectively enrolled. The prevalence of colorectal adenoma was compared between subjects with or without gallbladder polyps. Furthermore, a logistic regression analysis was performed to determine the independent risk factors for colorectal adenoma in these subjects.

Results

Of the 581 participants, 55 presented with gallbladder polyps and 526 did not have gallbladder polyps. Participants with gallbladder polyps showed a trend toward a higher prevalence of colorectal adenoma than those without gallbladder polyps (52.7% vs. 39.2%, P=0.051). Although the result was not statistically significant, gallbladder polyps were found to be a possible risk factor for colorectal adenoma (odds ratio=1.796, 95% confidence interval=0.986-3.269, P=0.055), even after adjusting for potential confounding factors. There was no difference observed in colorectal adenoma characteristics between the two groups.

Conclusions

Our results suggest a possible association between gallbladder polyps and colorectal adenomas. Future studies with larger cohorts are warranted to further investigate this matter.

Mechanisms linking excess adiposity and carcinogenesis promotion

Obesity constitutes one of the most important metabolic diseases being associated to insulin resistance development and increased cardiovascular risk. Association between obesity and cancer has also been well established for several tumor types, such as breast cancer in post-menopausal women, colorectal, and prostate cancer. Cancer is the first death cause in developed countries and the second one in developing countries, with high incidence rates around the world. Furthermore, it has been estimated that 15-20% of all cancer deaths may be attributable to obesity. Tumor growth is regulated by interactions between tumor cells and their tissue microenvironment. In this sense, obesity may lead to cancer development through dysfunctional adipose tissue and altered signaling pathways. In this review, three main pathways relating obesity and cancer development are examined: (i) inflammatory changes leading to macrophage polarization and altered adipokine profile; (ii) insulin resistance development; and (iii) adipose tissue hypoxia. Since obesity and cancer present a high prevalence, the association between these conditions is of great public health significance and studies showing mechanisms by which obesity lead to cancer development and progression are needed to improve prevention and management of these diseases.

The role of obesity in gastrointestinal cancer: evidence and opinion

There is increasing recognition of the impact of being overweight and obese on the development of cancers at diverse sites including the gastrointestinal tract. Large epidemiological studies indicate that up to 14% of tumours may be related to obesity. Pathophysiological mechanisms underpinning this association are not well understood and so are discussed in this review.

Obesity: an epidemiological perspective from Asia and its relationship to gastrointestinal and liver cancers

Obesity is major health problem in the Asia-Pacific region. The proportion of people who are overweight and obese in the region has increased dramatically and is closely linked to the increasing affluence in the region. While the body mass index has been used as a yardstick in many published studies, it has been noted that Asian patients have a greater percentage body fat for a given body mass index and especially abdominal or visceral obesity. The association of obesity and cancers is intriguing and worrisome at the same time, as obesity is rising exponentially throughout the world especially in the Asia-Pacific region. Evidence of its association with gastrointestinal cancers is well documented and is reported with cardioesophageal, colorectal, liver, pancreatic, and gallbladder cancers. The strength of association varies between individual cancers but is of particular concern with colorectal cancer, which is perhaps the fastest emerging cancer in this region. Biological mechanisms for obesity-related carcinogenesis have been described, which includes insulin resistance and secretion of adipokines and chronic inflammation. A "dose-response" relationship between severity of excess body weight and risks of cancer has been reported. However, there is a paucity of data looking at a decrease in incidence of these cancers with a decrease in body weight with treatment, for example, bariatric surgery. Such studies will be difficult to perform and which would require a long period of longitudinal follow-up.

Visfatin induces stromal cell-derived factor-1 expression by β1 integrin signaling in colorectal cancer cells

Obesity has been shown to be associated with the risk of colorectal cancer (CRC). Adipokines produced by the adipose tissue are linked to some malignancies, including CRC. Visfatin is an adipokine shown to be a biomarker of CRC malignant potential. In addition, the stromal cell-derived factor-1 (SDF-1) has been reported to play a role in CRC progression. Although the relationship between visfatin and CRC has been established, the underlying mechanism has not been clarified. We investigated the molecular mechanism governing the interaction between visfatin stimulation and SDF-1 expression in human CRC cell lines. We found that visfatin stimulation led to an increase in the expression and secretion of SDF-1 in CRC DLD-1 and SW48 cells. Experiments involving specific inhibitors and small interfering RNA demonstrated that the activation of ERK and p38 mitogen-activated protein kinase (MAPK) pathways are critical for visfatin-induced SDF-1 expression. Analysis of transcription factor binding using ELISA and luciferase reporter assays revealed that visfatin increased NF-κB- and AP-1-DNA-binding activities in DLD-1 cells. Inhibition of NF-κB and AP-1 activation blocked the visfatin-induced expression and activity of the SDF-1 promoter. The effect of visfatin on DLD-1 signaling and SDF-1 expression was mediated by β1 integrin. In summary, these findings provide novel insights pertaining to the pathophysiological role of visfatin in CRC.

Pathophysiology of human visceral obesity: an update

Excess intra-abdominal adipose tissue accumulation, often termed visceral obesity, is part of a phenotype including dysfunctional subcutaneous adipose tissue expansion and ectopic triglyceride storage closely related to clustering cardiometabolic risk factors. Hypertriglyceridemia; increased free fatty acid availability; adipose tissue release of proinflammatory cytokines; liver insulin resistance and inflammation; increased liver VLDL synthesis and secretion; reduced clearance of triglyceride-rich lipoproteins; presence of small, dense LDL particles; and reduced HDL cholesterol levels are among the many metabolic alterations closely related to this condition. Age, gender, genetics, and ethnicity are broad etiological factors contributing to variation in visceral adipose tissue accumulation. Specific mechanisms responsible for proportionally increased visceral fat storage when facing positive energy balance and weight gain may involve sex hormones, local cortisol production in abdominal adipose tissues, endocannabinoids, growth hormone, and dietary fructose. Physiological characteristics of abdominal adipose tissues such as adipocyte size and number, lipolytic responsiveness, lipid storage capacity, and inflammatory cytokine production are significant correlates and even possible determinants of the increased cardiometabolic risk associated with visceral obesity. Thiazolidinediones, estrogen replacement in postmenopausal women, and testosterone replacement in androgen-deficient men have been shown to favorably modulate body fat distribution and cardiometabolic risk to various degrees. However, some of these therapies must now be considered in the context of their serious side effects. Lifestyle interventions leading to weight loss generally induce preferential mobilization of visceral fat. In clinical practice, measuring waist circumference in addition to the body mass index could be helpful for the identification and management of a subgroup of overweight or obese patients at high cardiometabolic risk.

The association between obesity and colorectal adenoma: systematic review and meta-analysis

OBJECTIVE

Obesity (body mass index [BMI] ≥30) or overweight (25 ≤ BMI ≤29.9) has been reported to be a risk factor for colorectal adenoma (CRA). However, this association remains controversial. The aim of this study was to determine the association between overweight or obesity and CRA.

DESIGN

Systematic review and meta-analysis were conducted using English language studies from EMBASE and MEDLINE. Appropriate observational studies were selected from 1966 through September 2011. Adjusted odds ratios (ORs) were extracted from each study.

RESULTS

One hundred and seventy full-text articles were reviewed after retrieving 1199 initial search results. Five studies in which BMI was treated as continuous variable, three studies in which BMI was dichotomized using a cutoff value of 25, three studies in which BMI was categorized into three groups using values of 22 and 25, and eight studies in which BMI was categorized into three groups using values of 25 and 30 were selected. Regarding risk for CRA, pooled OR [95% CI] of one increment increase in BMI was 1.02 [0.99-1.03] (random effects model [REM]), while that of BMI ≥ 25 was 1.27 [1.15-1.4] (Fixed effects model). Pooled ORs [95% CI] of BMI ≥ 22 and BMI ≥ 25 was 1.42 [0.69-2.9] [REM] and 1.81 [0.36-9.1] [REM], respectively. Pooled ORs [95% CI] of BMI ≥ 25 and BMI ≥ 30 was 1.16 [0.98-1.38] [REM] and 1.47 [1.18-1.83] [REM], respectively.

CONCLUSION

Obesity and overweight are significant risk factors for CRA. However, there are no data showing linear relationship between increasing BMI and CRA.

Body mass index increases risk for colorectal adenomas based on meta-analysis

BACKGROUND & AIMS

There have been inconsistent results published about the relationship between excess body weight, expressed as increased body mass index (BMI), and risk of colorectal adenoma (CRA). We conducted a meta-analysis to explore this relationship. We focused on whether the relationship varied based on the sex of the study subjects, study design, features of the polyps, or potential confounders, including alcohol use, nonsteroidal anti-inflammatory drug use, smoking, and exercise.

METHODS

We identified studies by performing a literature search of Medline, EMBASE, and ISI Web of Science through July 31, 2011, and by searching the reference lists of pertinent articles. We analyzed 36 independent studies, which included 29,860 incident cases of CRA. Summary relative risks with their 95% confidence intervals (CIs) were calculated with a random-effects model. Between-study heterogeneity was assessed using Cochran's Q statistic and I(2) analyses.

RESULTS

Overall, a 5-unit increase in BMI (calculated as kg/m(2)) increased the risk for CRA (summary relative risk = 1.19; 95% CI: 1.13-1.26), although there was a high level of heterogeneity among studies (P(heterogeneity) < .001; I(2) = 76.8%). Subgroup analyses revealed that the increased risk of CRA in obese individuals was independent of race, geographic location, study design, sex, adenoma progression, and confounders. The association between increased BMI and risk for CRA was stronger for colon than rectal adenoma.

CONCLUSIONS

Based on a meta-analysis, increased BMI increases the risk for colon but not rectal adenoma. Unlike colorectal cancer, there is no sex difference in the relationship between increased BMI and risk of CRA.

Body mass index and death rate of colorectal cancer among a national cohort of U.S. adults

Substantial evidence suggests that increasing adiposity is associated with an increased death rate of colorectal cancer, but no studies were conducted among national representative populations in the United States. The current study examined the death rate across BMI levels in 7,016 adults who participated in the National Health and Nutrition Examination Survey in 1971-1975. BMI categories were defined as normal (18.5-24.9 kg/m(2)), overweight (25-29.9), and obese (≥30). A total of 519 cancer deaths were identified during a 17-yr follow-up with 118,998 person-years. No significantly increased death rates of total cancers, lung, breast, and prostate cancer were observed among participants with an increased BMI. However, colorectal cancer death rates were 0.39, 0.68, and 0.96/1,000 person-years, respectively, for normal weight, overweight, and obese (P value for log-rank trend test < 0.001), and the corresponding adjusted hazard ratios [95% confidence intervals (CI)] were 1.00 (reference), 1.25 (95% CI = 0.72-2.19), and 2.04 (1.08-3.83), respectively. No gender difference of the association was identified. The authors conclude that a significantly increased death rate of colorectal cancer was associated with excess body weight. The current study is an addition to the expanding body of literature indicating an increased risk of colorectal cancer development among the obese.

Metabolic syndrome, lifestyle risk factors, and distal colon adenoma: A retrospective cohort study

AIM: To investigate relationships between colorectal adenoma incidence, metabolic syndrome (MS) components and lifestyle factors.

METHODS: We conducted a retrospective cohort study using data from individuals who had multiple sigmoidoscopies for colon cancer at the Health Promotion Center of Ulsan University Hospital in Korea from 1998 to 2007.

RESULTS: By multivariate analysis, the incidence of distal colon adenoma was increased by more than 1.76 times in individuals with at least one component of MS compared to those without a component of MS. After adjustment for age, gender, smoking, drinking, and physical exercise, only high body mass index (BMI) was significantly associated with the incidence of distal colon adenoma (Hazard ratio 1.66, 95% confidence interval 1.05-2.62).

CONCLUSION: Our results suggest that high BMI may increase the risk of colorectal adenoma in Korean adults.

Stepwise relationship between components of metabolic syndrome and risk of colorectal adenoma in a Taiwanese population receiving screening colonoscopy

BACKGROUND/PURPOSE

Metabolic syndrome (MS) is a cluster of diseases related to insulin resistance and is an important cardiovascular risk factor. In addition, MS has been linked to some malignancies, including colorectal cancer. Colon adenoma is a well-established pre-malignant lesion of colorectal cancer. The aim of this study was to determine the effect of various components of MS on the risk of colorectal adenoma.

METHODS

From October 2004 to April 2006, 3106 subjects who had undergone complete colonoscopy for health examinations at the hospital were enrolled. MS was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III definition for South Asians and Chinese. Multivariate logistic regression was used to analyze the association between components of MS and colorectal adenoma.

RESULTS

Of the 3106 subjects, the mean age was 47.1 ± 10.8 years and there were 397 (13%) subjects with pathologically proven colorectal adenoma. Male sex, old age (=50 years), current smokers, and abdominal obesity were associated with increasing risk of colorectal adenoma. MS was associated with increased risk of colorectal adenoma (odds ratio: 1.71, 95% confidence interval: 1.34-2.71), and this risk increased with the number of metabolic components. Multiple and synchronous adenomas of the proximal and distal colon were positively associated with MS.

CONCLUSION

Subjects with metabolic syndrome have increased risk of developing colorectal adenoma. Screening colonoscopy for prevention of colorectal adenoma might be warranted when abdominal obesity or more than three components of MS are present.

Excess body weight and obesity--the link with gastrointestinal and hepatobiliary cancer

Excess body weight (EBW) is an independent risk factor for many human malignancies, including cancers throughout the gastrointestinal and hepatobiliary tract from the esophagus to the colorectum. The relative risk of gastrointestinal cancer in obese individuals is approximately 1.5-2.0 times that for normal weight individuals, with organ-specific and gender-specific differences for specific cancers. The association between EBW and risk of premalignant stages of gastrointestinal carcinogenesis, such as colorectal adenoma and Barrett esophagus, is similar, implying a role for EBW during the early stages of carcinogenesis that could be relevant to preventative strategies. EBW also impacts negatively on gastrointestinal cancer outcomes. The mechanistic basis of the association between EBW and carcinogenesis remains incompletely understood. Postulated mechanisms include increased insulin and insulin-like growth factor signaling and chronic inflammation (both linked to the metabolic syndrome), as well as signaling via adipokines, such as leptin. The role of obesity-related changes in the intestinal microbiome in gastrointestinal carcinogenesis deserves further attention. Whether weight loss leads to reduced future gastrointestinal and liver cancer risk has yet to be fully explored. There is some support for the idea that weight loss negatively regulates colorectal carcinogenesis. In addition, data suggest a reduction in risk of several cancers in the first 10 years after bariatric surgery.

Colorectal cancer: what should patients and families be told to lower the risk of colorectal cancer?

Colorectal cancer (CRC) is the second most common cause of cancer-related death in the United States. CRC, however, is potentially preventable, and several strategies may be employed to decrease the incidence of and mortality from CRC. Understanding of individual risk and adherence to screening and surveillance recommendations undoubtedly will reduce CRC-associated deaths. Several natural and synthetic chemopreventive agents may prove effective for both primary and secondary CRC chemoprevention. Finally, dietary modifications (ie, increased dietary fiber, fruits and vegetables, and decreased red meat) and other lifestyle changes (i.e., increased physical activity, weight maintenance, avoidance of smoking, and moderation of alcohol intake) also may lower the risk of developing CRC.

[The difference of clinicopathologic features according to leptin expression in colorectal adenoma]

BACKGROUND/AIMS

Colorectal adenoma and cancer are known to be associated with obesity. Leptin, an adipocyte-derived hormone that plays a crucial role in obesity has been suggested as a growth factor in colon cancer. However, the association between adenoma and leptin remains controversial. We evaluated the leptin expression in human colorectal adenoma and its correlation to clinicopathologic factors.

METHODS

Leptin expression was assessed by immunohistochemistry in 91 samples of colorectal adenoma larger than 5 mm, which were removed by endoscopic polypectomy. All patients underwent colonoscopy for cancer screening at Seoul Paik Hospital from 2007 to 2008 and we only included the patients less than 50 years of age. Leptin expression and its relationship with clinicopathologic features were analyzed.

RESULTS

Eighty samples were available for the interpretation of leptin expression and showed positive in 42 (52.5%) cases and negative in 38 (47.5%) cases. As body mass index (BMI) increased based on World Health Organization (WHO) classification the positivity of leptin expression also increased (ptrend=0.02). In leptin positive group, the correlation of leptin expression with adenoma size and histological showed positive tendency without statistical significance.

CONCLUSIONS

Leptin expression of colorectal adenoma was associated with BMI. The question of whether leptin contributes to colorectal adenoma development is unresolved and will require additional studies.

Anthropometric factors in adulthood and risk of colorectal adenomas: The French E3N-EPIC prospective cohort

Anthropometric factors have been associated with colorectal cancer and adenomas but with conflicting results in women or regarding adenoma characteristics. The authors aimed to explore associations between anthropometric factors (height, weight, body mass index, waist and hip circumferences, and weight changes) and adenoma risk. They analyzed the 17,391 women of the French Etude épidémiologique des femmes de la Mutuelle Générale de l'Education Nationale (E3N)-European Prospective Investigation into Cancer and Nutrition (EPIC) cohort who underwent a colonoscopy during follow-up (1993-2002), including 1,408 who developed a first colorectal adenoma. In Cox multivariate proportional hazard regression models, obesity was associated with an increased colorectal adenoma risk (hazard ratio = 1.53, 95% confidence interval: 1.21, 1.94). This association was restricted to left colon adenomas (P(homogeneity) = 0.05 and 0.01 for colon vs. rectum and right vs. left colon, respectively), with a dose-effect relation observed from 22 kg/m². A high waist circumference was also associated with left colon adenoma risk (hazard ratio = 1.81, 95% confidence interval: 1.36, 2.41). Mean weight gain over 0.5 kg/year was associated with a 23% increased colorectal adenoma risk. Associations did not differ between advanced and nonadvanced adenomas. In conclusion, study findings suggest that obesity and weight gain are associated with early colorectal carcinogenesis in women, and specifically regarding the distal colon.

Elevated expression of tumor necrosis factor-alpha signaling molecules in colonic tumors of Zucker obese (fa/fa) rats

Zucker obese rats are highly sensitive to colon cancer and possess a plethora of metabolic abnormalities including elevated levels of cytokine tumor necrosis factor-alpha (TNF-alpha). The main objective of this study was to determine if physiologically elevated TNF-alpha affects colonic tumor phenotype with regard to an altered TNF-alpha signaling pathway. Zucker obese (fa/fa, homozygous recessive for dysfunctional leptin receptors), Zucker lean (Fa/fa, Fa/Fa) and Sprague-Dawley (SD) rats were injected twice with azoxymethane (10 mg/kg) over 2 weeks. After 30 weeks, the animals were terminated and physiological and tumor parameters were assessed. Obese rats had notably higher body and organ weights as well as plasma TNF-alpha, insulin and leptin levels than lean or SD animals. A 100% tumor incidence and significantly higher tumor size, multiplicity and burden were found in obese rats compared to the lean group that had 47.8% tumor incidence. The SD group had the lowest tumor incidence (20.0%). Tumors from obese animals had higher protein levels of TNF-alpha, TNF-alpha-receptor-2 (TNFR2), nuclear transcription factor-kappaB (NF-kappaB) and IkappaB-kinasebeta (IKKbeta) compared to lean animals. In both obese and lean groups, expression levels of these proteins were higher in tumors than in surrounding, normal-appearing colonic mucosae. These findings support an important role for TNF-alpha signaling in tumorigenesis and demonstrate that tumors growing in an obese state had significantly different expression levels of TNFR2 and NF-kappaB, proteins known to play a critical role in growth and survival, than those growing in the lean state. It is concluded that the physiological state of the host intricately affects tumor phenotype.

Up-regulation of the novel proinflammatory adipokines lipocalin-2, chitinase-3 like-1 and osteopontin as well as angiogenic-related factors in visceral adipose tissue of patients with colon cancer

BACKGROUND

Obesity is widely recognised as an important risk factor for colorectal cancer (CC).

AIM

The study aimed to evaluate the effect of CC on circulating concentrations and gene expression levels of inflammatory and angiogenesis-related factors in human visceral adipose tissue (VAT).

METHODS

VAT biopsies were obtained from 18 healthy individuals and 11 patients with CC. Real-time polymerase chain reactions were performed to quantify gene expression levels and zymographic analyses were used to determine the activity of matrix metalloproteinases (MMPs).

RESULTS

Patients with CC exhibited increased mRNA expression levels of lipocalin-2 (P=.014), osteopontin (P=.027), tumor necrosis factor-α (TNF-α) (P=.016) and chitinase-3 like-1 (P=.006) compared to control subjects in VAT. Gene expression levels of hypoxia-inducible factor-1 α, vascular endothelial growth factor and MMP-2 were significantly higher (P<.05) in VAT of patients with CC. The expression of insulin-like growth factor I, insulin growth factor binding protein 3 and MMP-9 followed the same trend, although no significant differences were reached. The enzymatic activity of MMP-9 was increased (P<.001) in patients with CC. Furthermore, individuals with CC showed increased (P<.05) circulating concentrations of the inflammatory markers interleukin-6, tumour necrosis factor α and hepatocyte growth factor, whereas levels of the anti-inflammatory adipokine adiponectin were decreased (P<.01).

CONCLUSION

These findings represent the first observation that mRNA levels of the novel inflammatory factors lipocalin-2, chitinase-3 like-1 and osteopontin are increased in human VAT of subjects with CC. This observation together with the up-regulation of angiogenic factors suggests that adipokines secreted by VAT may be involved in the development of colon cancer.

Obesity and gastrointestinal cancer

BACKGROUND

There is emerging evidence of a strong association between obesity and gastrointestinal cancer. This review summarizes the evidence from an epidemiological and pathophysiological perspective.

METHODS

Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles were identified. Selection of articles was based on peer review, journal and relevance.

RESULTS

Numerous epidemiological studies consistently identified an increased risk of developing oesophageal adenocarcinoma and colorectal carcinoma in the obese. The association between obesity and other gastrointestinal malignancies was less robust. Sex seems important with respect to cancer risk. Adipose tissue, particularly viscerally located fat, is metabolically active and exerts systemic endocrine effects. Putative pathophysiological mechanisms linking obesity and carcinogenesis include the insulin-like growth factor axis, adipocytokines and sex steroids.

CONCLUSION

A better understanding of the mechanisms that link obesity and cancer may uncover targets for intervention. Tackling obesity may result in a reduction in the incidence in addition to mortality of certain cancers in future.

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

BACKGROUND & AIMS

Small studies have shown inconsistent results regarding the association between abdominal visceral adipose tissue and colorectal adenomas. We evaluated the effects of visceral adipose tissue volume on the development and growth of colorectal adenomas.

METHODS

A total of 3922 participants underwent colonoscopy and computed tomography from February to November 2008. The associations between waist circumference, visceral adipose tissue volume, and colorectal adenomas were estimated with adjusted odds ratios and 95% confidence intervals (CIs). In addition, the association between characteristics of colorectal adenomas and visceral adipose tissue volume was evaluated.

RESULTS

Compared with participants who had visceral adipose tissue volume of less than 500 cm(3), the odds ratio for colorectal adenoma was 1.09 (95% CI, 0.87-1.36) for a volume of 500 to 999 cm(3), 1.33 (95% CI, 1.04-1.69) for a volume of 1000 to 1499 cm(3), and 1.43 (95% CI, 1.06-1.94) for a volume of 1500 cm(3) or greater. The risk of colorectal adenomas increased with increasing visceral adipose tissue volume in both sexes (P trend = .004 in men and .009 in women). Waist circumference was associated with colorectal adenomas in men (P trend = .02), but not in women. High volume of visceral adipose tissue (>or=1000 cm(3)) had a positive association with larger adenomas (>or=10 mm) and multiple adenomas.

CONCLUSIONS

Abdominal visceral adipose tissue volume can contribute to the development and growth of colorectal adenomas, and it was a better predictor for risk of colorectal adenomas than body mass index or waist circumference in both sexes.