Non-alcoholic fatty liver disease with obesity as an independent predictor for incident gastric and colorectal cancer: a population-based longitudinal study

Association of MASLD with the risk of extrahepatic cancers: A systematic review and meta-analysis of 18 cohort studies

BACKGROUND

Numerous recent studies have explored the association between metabolic dysfunction-associated steatotic liver disease (MASLD) and the risk of various extrahepatic cancers. However, the conclusions were inconclusive. The aim of this study was to clarify this relationship by conducting a robust meta-analysis.

METHODS

Systematic searches were conducted on PubMed, Embase and Web of Science databases to identify relevant cohort studies published prior to February 2024. Hazard ratios (HRs) and their corresponding 95% confidence intervals (95% CIs) were combined using a random-effects model in this meta-analysis.

RESULTS

Eighteen cohort studies (approximately 16.7 million participants) were finally included in this meta-analysis. MASLD was linked to a higher risk of extrahepatic cancers, such as gastric (n = 10, HR = 1.47, 95% CI: 1.07-2.01), colorectal (n = 13, HR = 1.33, 95% CI: 1.16-1.53), pancreatic (n = 8, HR = 1.41, 95% CI: 1.11-1.79), biliary tract (n = 5, HR = 1.27, 95% CI: 1.18-1.37), thyroid (n = 6, HR = 1.46, 95% CI: 1.02-2.09), urinary system (n = 10, HR = 1.45, 95% CI: 1.25-1.69), breast (n = 11, HR = 1.17, 95% CI: 1.08-1.26) and female genital organ cancers (n = 10, HR = 1.36, 95% CI: 1.11-1.66). However, there was no statistically significant association between MASLD and the risk of head and neck (n = 6, HR = 1.03, 95% CI: 99-1.07), oesophageal (n = 9, HR = 1.26, 95% CI: 0.86-1.86), lung (n = 9, HR = 1.01, 95% CI: 0.92-1.10), prostate (n = 9, HR = 1.06, 95% CI: 0.94-1.19) or small intestine cancer (n = 2, HR = 1.75, 95% CI: 1.00-3.06).

CONCLUSIONS

This latest large-scale meta-analysis indicated that MASLD was associated with an increased risk of various extrahepatic cancers, such as gastric, colorectal, pancreatic, biliary duct, thyroid, urinary system, breast, skin and female genital cancers. Further research is needed to investigate the mechanisms underlying these associations.

NON-ALCOHOLIC FATTY LIVER DISEASE AND EXTRA-HEPATIC CANCER: A NARRATIVE REVIEW

BACKGROUND

Recently, significant associations between non-alcoholic fatty liver disease (NAFLD) and extra-hepatic cancer have been reported.

OBJECTIVE

To carry out a comprehensive review of the current evidence in the literature on the association between NAFLD and extra-hepatic cancer.

METHODS

A narrative literature review was performed through an online search for the MeSH terms "fatty liver" and "cancer" in MEDLINE (via PubMed) and LILACS (via BVS). Original studies that described the impact of NAFLD on different types of extra-hepatic malignancies were included.

RESULTS

After careful analysis, nine prospective cohort studies, one retrospective cohort study, three case-control studies, and three cross-sectional studies were selected.

CONCLUSION

There is consistent evidence on the association between NAFLD and extra-hepatic carcinogenesis, especially in relation to colorectal, gastric, pancreatic, breast, prostate, and bladder cancers.

Global epidemiology of type 2 diabetes in patients with NAFLD or MAFLD: a systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD) shares common pathophysiological mechanisms with type 2 diabetes, making them significant risk factors for type 2 diabetes. The present study aimed to assess the epidemiological feature of type 2 diabetes in patients with NAFLD or MAFLD at global levels.

METHODS

Published studies were searched for terms that included type 2 diabetes, and NAFLD or MAFLD using PubMed, EMBASE, MEDLINE, and Web of Science databases from their inception to December 2022. The pooled global and regional prevalence and incidence density of type 2 diabetes in patients with NAFLD or MAFLD were evaluated using random-effects meta-analysis. Potential sources of heterogeneity were investigated using stratified meta-analysis and meta-regression.

RESULTS

A total of 395 studies (6,878,568 participants with NAFLD; 1,172,637 participants with MAFLD) from 40 countries or areas were included in the meta-analysis. The pooled prevalence of type 2 diabetes among NAFLD or MAFLD patients was 28.3% (95% confidence interval 25.2-31.6%) and 26.2% (23.9-28.6%) globally. The incidence density of type 2 diabetes in NAFLD or MAFLD patients was 24.6 per 1000-person year (20.7 to 29.2) and 26.9 per 1000-person year (7.3 to 44.4), respectively.

CONCLUSIONS

The present study describes the global prevalence and incidence of type 2 diabetes in patients with NAFLD or MAFLD. The study findings serve as a valuable resource to assess the global clinical and economic impact of type 2 diabetes in patients with NAFLD or MAFLD.

Longitudinal Outcomes Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease: A Meta-analysis of 129 Studies

BACKGROUND & AIMS

The progression of metabolic dysfunction-associated steatotic liver disease (MASLD) has been found to manifest in a series of hepatic and extrahepatic complications. A comprehensive meta-analysis of the longitudinal outcomes associated with MASLD has yet to be conducted.

METHODS

To investigate the longitudinal outcomes associated with MASLD, Medline and Embase databases were searched to identify original studies that evaluated the longitudinal risks of incident clinical outcomes among MASLD patients compared with non-MASLD individuals. DerSimonian Laird random-effects meta-analysis was performed. Pooled effect estimates were calculated, and heterogeneity among studies was evaluated.

RESULTS

One hundred twenty-nine studies were included in the meta-analysis. Meta-analysis revealed a significant increase in the risk of cardiovascular outcomes (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.27-1.60; P < .01), various metabolic outcomes such as incident hypertension (HR, 1.75; 95% CI, 1.46-2.08; P < .01), diabetes (HR, 2.56; 95% CI, 2.10-3.13; P < .01), pre-diabetes (HR, 1.69; 95% CI, 1.22-2.35; P < .01), metabolic syndrome (HR, 2.57; 95% CI, 1.13-5.85; P = .02), chronic kidney disease (HR, 1.38; 95% CI, 1.27-1.50; P < .01), as well as all cancers (HR, 1.54; 95% CI, 1.35-1.76; P < .01) among MASLD patients compared with non-MASLD individuals. By subgroup analysis, MASLD patients with advanced liver disease (HR, 3.60; 95% CI, 2.10-6.18; P < .01) were also found to be associated with a significantly greater risk (P = .02) of incident diabetes than those with less severe MASLD (HR, 1.63; 95% CI, 1.0-2.45; P = .02) when compared with non-MASLD.

CONCLUSIONS

The present study emphasizes the association between MASLD and its clinical outcomes including cardiovascular, metabolic, oncologic, and other outcomes. The multisystemic nature of MASLD found in this analysis requires treatment targets to reduce systemic events and end organ complications.

Association of nonalcoholic fatty liver disease with colorectal adenomatous polyps and non-adenomatous polyps: a cross-sectional study

AIM

This study aimed to investigate the association between non-alcoholic fatty liver disease (NAFLD) and both colorectal adenomatous polyps and non-adenomatous polyps, in order to provide evidence for the prevention of colorectal cancer (CRC) in patients with NAFLD.

METHODS

A retrospective, cross-sectional study was conducted at the First People's Hospital of Kunshan, Jiangsu, China. The study included 3028 adults who underwent abdominal ultrasonography and colonoscopy over a 5 year period. We compared characteristics among patients with adenomatous polyps, non-adenomatous polyps, and without colorectal polyps using descriptive statistics. Logistic regression analyses were used to detect associations between NAFLD with the prevalence of adenomatous polyps and non-adenomatous polyps. NAFLD was determined by abdominal ultrasound. Colorectal polyps were assessed by data in the colonoscopy report and pathology report.

RESULTS

A total of 65% of patients with NAFLD had colorectal polys (52% adenomatous polyps and 13% non-adenomatous polyps), and 40% of patients without NAFLD had polyps (29% adenomatous polyps and 11% non-adenomatous polyps). After adjusting for confounding variables, NAFLD was significantly associated with the prevalence of adenomatous in males and females [odds ratio (OR) = 1.8, 95% confidence interval (CI): 1.6-2.2, P  < 0.01], but was not associated with non-adenomatous polyps (OR = 1.2, 95% CI:0.9-1.5, P  > 0.05).

CONCLUSION

NAFLD is associated with an increased risk of colorectal adenomatous polyps compared to the absence of polyps, but not associated with an increased risk of non-adenomatous polyps. These results provide important evidence for the prevention of CRC in patients with NAFLD.

The association between hepatic steatosis and incident cardiovascular disease, cancer, and all-cause mortality in a US multicohort study

BACKGROUND AND AIMS

NAFLD strongly associates with cardiovascular disease (CVD) risk factors; however, the association between NAFLD and incident CVD, CVD-related mortality, incident cancer, and all-cause mortality is unclear.

APPROACH AND RESULTS

We included 10,040 participants from the Framingham Heart Study, the Coronary Artery Risk Development in Young Adults Study, and the Multi-ethnic Study of Atherosclerosis to assess the longitudinal association between liver fat (defined on CT) and incident CVD, CVD-related mortality, incident cancer, and all-cause mortality. We performed multivariable-adjusted Cox regression models including age, sex, diabetes, systolic blood pressure, alcohol use, smoking, HDL, triglycerides, and body mass index at baseline or time-varying covariates. The average age was 51.3±3.3 years and 50.6% were women. Hepatic steatosis was associated with all-cause mortality after 12.7 years of mean follow-up when adjusting for baseline CVD risk factors, including body mass index (HR: 1.21, 1.04-1.40); however, the results were attenuated when utilizing time-varying covariates. The association between hepatic steatosis and incident CVD was not statistically significant after we accounted for body mass index in models considering baseline covariates or time-varying covariates. We observed no association between hepatic steatosis and CVD-related mortality or incident cancer.

CONCLUSIONS

In this large, multicohort study of participants with CT-defined hepatic steatosis, accounting for change in CVD risk factors over time attenuated associations between liver fat and overall mortality or incident CVD. Our work highlights the need to consider concurrent cardiometabolic disease when determining associations between NAFLD and CVD and mortality outcomes.

Extrahepatic Outcomes of Nonalcoholic Fatty Liver Disease: Nonhepatocellular Cancers

Nonalcoholic fatty liver disease (NAFLD) encompasses the entire spectrum of fatty liver disease in individuals without significant alcohol consumption, including isolated steatosis, steatohepatitis, and cirrhosis. The overall global prevalence of NAFLD is estimated to be 30%, and the associated clinical and economic burden will continue to increase. NAFLD is a multisystemic disease with established links to cardiovascular disease, type 2 diabetes, metabolic syndrome, chronic kidney disease, polycystic ovarian syndrome, and intra- and extrahepatic malignancies. In this article the authors review the potential mechanisms and current evidence for the association between NAFLD and extrahepatic cancers and the resultant impact on clinical outcomes.

Comparison between metabolic-associated fatty liver disease and nonalcoholic fatty liver disease: From nomenclature to clinical outcomes

As a result of the obesity epidemic, Nonalcoholic fatty liver disease (NAFLD) and its complications have increased among millions of people. Consequently, a group of experts recommended changing the term NAFLD to an inclusive terminology more reflective of the underlying pathogenesis; metabolic-associated fatty liver disease (MAFLD). This new term of MAFLD has its own disease epidemiology and clinical outcomes prompting efforts in studying its differences from NAFLD. This article discusses the rationale behind the nomenclature change, the main differences, and its clinical implications.

Terpenoids: Natural Compounds for Non-Alcoholic Fatty Liver Disease (NAFLD) Therapy

Natural products have been the most productive source for the development of drugs. Terpenoids are a class of natural active products with a wide range of pharmacological activities and therapeutic effects, which can be used to treat a variety of diseases. Non-alcoholic fatty liver disease (NAFLD), a common metabolic disorder worldwide, results in a health burden and economic problems. A literature search was conducted to obtain information relevant to the treatment of NAFLD with terpenoids using electronic databases, namely PubMed, Web of Science, Science Direct, and Springer, for the period 2011-2021. In total, we found 43 terpenoids used in the treatment of NAFLD. Over a dozen terpenoid compounds of natural origin were classified into five categories according to their structure: monoterpenoids, sesquiterpenoids, diterpenoids, triterpenoids, and tetraterpenoids. We found that terpenoids play a therapeutic role in NAFLD, mainly by regulating lipid metabolism disorder, insulin resistance, oxidative stress, and inflammation. The AMPK, PPARs, Nrf-2, and SIRT 1 pathways are the main targets for terpenoid treatment. Terpenoids are promising drugs and will potentially create more opportunities for the treatment of NAFLD. However, current studies are restricted to animal and cell experiments, with a lack of clinical research and systematic structure-activity relationship (SAR) studies. In the future, we should further enrich the research on the mechanism of terpenoids, and carry out SAR studies and clinical research, which will increase the likelihood of breakthrough insights in the field.

2019 Global NAFLD Prevalence: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The increasing rates of obesity and type 2 diabetes mellitus may lead to increased prevalence of nonalcoholic fatty liver disease (NAFLD). We aimed to determine the current and recent trends on the global and regional prevalence of NAFLD.

METHODS

Systematic search from inception to March 26, 2020 was performed without language restrictions. Two authors independently performed screening and data extraction. We performed meta-regression to determine trends in NAFLD prevalence.

RESULTS

We identified 17,244 articles from literature search and included 245 eligible studies involving 5,399,254 individuals. The pooled global prevalence of NAFLD was 29.8% (95% confidence interval [CI], 28.6%-31.1%); of these, 82.5% of included articles used ultrasound to diagnose NAFLD, with prevalence of 30.6% (95% CI, 29.2%-32.0%). South America (3 studies, 5716 individuals) and North America (4 studies, 18,236 individuals) had the highest NAFLD prevalence at 35.7% (95% CI, 34.0%-37.5%) and 35.3% (95% CI, 25.4%-45.9%), respectively. From 1991 to 2019, trend analysis showed NAFLD increased from 21.9% to 37.3% (yearly increase of 0.7%, P < .0001), with South America showing the most rapid change of 2.7% per year, followed by Europe at 1.1%.

CONCLUSIONS

Despite regional variation, the global prevalence of NAFLD is increasing overall. Policy makers must work toward reversing the current trends by increasing awareness of NAFLD and promoting healthy lifestyle environments.

Analysis of the correlation between non-alcoholic fatty liver disease and the risk of colorectal neoplasms

This study aims at assessing the potential association between non-alcoholic fatty liver disease (NAFLD) and colorectal neoplasms (CRN). PubMed, Cochrane Library, and Embase were searched for cohort studies. 14 cohort studies with a total population of 38,761,773 were included for meta-analysis after selection. The results showed that NAFLD is related to an increased risk of CRN (OR = 1.23; 95% CI: 1.14-1.32; I2 = 70.7%, p < 0.001). In the subgroup analysis, NAFLD were found to be the independent risk factor of colorectal adenoma (CRA) (OR = 1.29; 95% CI = 1.15-1.45; I2 = 66.4%) and colorectal cancer (CRC) (OR = 1.13; 95% CI = 1.12-1.15; I2 = 69.4%). There is no close correlation between smoking status of NAFLD patients and CRN. Interestingly, bioinformatics analysis revealed that there were overlap of dysregulated gene sets among NAFLD, CRC, and two recently identified regulated cell death types, ferroptosis and cuproptosis, respectively. Our meta- and bioinformatics analysis shows that NAFLD increases the risk of CRN. Ferroptosis and cuproptosis may be the critical links between NAFLD and CRN, respectively. These findings here support that NAFLD is necessary to be considered as an emerging risk factor for CRN.

Risk for hepatic and extra-hepatic outcomes in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is defined by presence of steatosis in more than 5% of liver cells. The gold standard for diagnosis is liver biopsy, but this is seldom achieved due to costs and risk for side effects, and that is why the diagnosis is mostly made based on a combination of radiology and exclusion of other liver diseases. Disease severity staging can be noninvasively achieved with radiological exams such as elastography or blood-based markers that usually have lower sensitivity and specificity. NAFLD is today the most common chronic liver disease globally with a prevalence estimated to be 25%. Fortunately, for many persons NAFLD is an incidental finding with a good prognosis. Whilst a major focus has been on liver-related outcomes in NAFLD, there has recently been an increased interest in extrahepatic consequences of NAFLD. The most commonly studied outcomes include cardiovascular disease and cancer. The risk of adverse outcomes generally differs according to the baseline fibrosis stage. There is a five-time higher risk of liver-related events in NAFLD patients with fibrosis stage 3 as compared to those with no or little fibrosis. Meanwhile, the presence of nonalcoholic steatohepatitis (NASH) does not seem to influence prognosis in addition to fibrosis stage. Patients with NAFLD clearly have a higher risk for cardiovascular outcomes compared to the general population, with a recent meta-analysis indicating a 37% increased hazard for cardiovascular events as opposed to individuals without NAFLD. The risk of liver cancer is increased, which is mostly driven by presence of cirrhosis, but the increased risk is present also in patients without cirrhosis, and to a greater extent than for other chronic liver disease. Around one-third of patients with NAFLD and liver cancer do not have cirrhosis. Additionally, the risk of extrahepatic malignancies is thought to be moderately increased, with most evidence for a link between NAFLD and colorectal cancer where the risk is approximately 50% higher compared to patients without NAFLD. A particularly salient point is if NAFLD can be considered an independent risk factor for outcomes. Many studies have not been able to adjust for key confounders, or suffer from different forms of bias. The clinical problem is nevertheless to identify persons with an increased risk for adverse hepatic and extrahepatic outcomes. We here discuss the evidence linking NAFLD to severe hepatic and extrahepatic outcomes.

Non-Alcoholic Fatty Liver Disease and Extrahepatic Cancers: A Wolf in Sheep’s Clothing?

Non-alcoholic fatty liver disease (NAFLD) is now considered the main driver and leading cause of chronic liver disease globally. The umbrella term NAFLD describes a range of liver conditions closely related to insulin resistance, metabolic syndrome, diabetes mellitus, obesity, and dyslipidemia. At the same time, several malignancies, including hepatocellular carcinoma and colorectal cancer, are considered to be common causes of death among patients with NAFLD. At first, our review herein aims to investigate the role of NAFLD in developing colorectal neoplasms and adenomatous polyps based on the current literature. We will also explore the connection and the missing links between NAFLD and extrahepatic cancers. Interestingly, any relationship between NAFLD and extrahepatic malignancies could be attributable to several shared metabolic risk factors. Overall, obesity, insulin resistance, metabolic syndrome, and related disorders may increase the risk of developing cancer. Therefore, early diagnosis of NAFLD is essential for preventing the progression of the disease and avoiding its severe complications. In addition, cancer screening and early detection in these patients may improve survival and reduce any delays in treatment.

Non-alcoholic fatty liver disease and increased risk of incident extrahepatic cancers: a meta-analysis of observational cohort studies

OBJECTIVE

We performed a meta-analysis of observational studies to quantify the magnitude of the association between non-alcoholic fatty liver disease (NAFLD) and risk of extrahepatic cancers.

DESIGN

We systematically searched PubMed, Scopus and Web of Science databases from the inception date to 30 December 2020 using predefined keywords to identify observational cohort studies conducted in individuals, in which NAFLD was diagnosed by imaging techniques or International Classification of Diseases codes. No studies with biopsy-proven NAFLD were available for the analysis. Meta-analysis was performed using random-effects modelling.

RESULTS

We included 10 cohort studies with 182 202 middle-aged individuals (24.8% with NAFLD) and 8485 incident cases of extrahepatic cancers at different sites over a median follow-up of 5.8 years. NAFLD was significantly associated with a nearly 1.5-fold to twofold increased risk of developing GI cancers (oesophagus, stomach, pancreas or colorectal cancers). Furthermore, NAFLD was associated with an approximately 1.2-fold to 1.5-fold increased risk of developing lung, breast, gynaecological or urinary system cancers. All risks were independent of age, sex, smoking, obesity, diabetes or other potential confounders. The overall heterogeneity for most of the primary pooled analyses was relatively low. Sensitivity analyses did not alter these findings. Funnel plots did not reveal any significant publication bias.

CONCLUSION

This large meta-analysis suggests that NAFLD is associated with a moderately increased long-term risk of developing extrahepatic cancers over a median of nearly 6 years (especially GI cancers, breast cancer and gynaecological cancers). Further research is required to decipher the complex link between NAFLD and cancer development.

Bariatric Surgery and Liver Disease: General Considerations and Role of the Gut-Liver Axis

Weight loss is a therapeutic solution for many metabolic disorders, such as obesity and its complications. Bariatric surgery aims to achieve lasting weight loss in all patients who have failed after multiple dietary attempts. Among its many benefits, it has been associated with the regression of non-alcoholic fatty liver disease (NAFLD), which is often associated with obesity, with evidence of substantial improvement in tissue inflammation and fibrosis. These benefits are mediated not only by weight loss, but also by favorable changes in systemic inflammation and in the composition of the gut microbiota. Changes in microbial metabolites such as short-chain fatty acids (SCFAs), capable of acting as endocrine mediators, and bile acids (BAs) as well as modifications of the gut-brain axis, are among the involved mechanisms. However, not all bariatric surgeries show beneficial effects on the liver; those leading to malabsorption can cause liver failure or a marked worsening of fibrosis and the development of cirrhosis. Nevertheless, there are still many unclear aspects, including the extent of the benefits and the magnitude of the risks of bariatric surgery in cirrhotic patients. In addition, the usefulness and the safety of these procedures in patients who are candidates to or who have undergone liver transplant need solid supporting evidence. This paper aims to review literature data on the use of bariatric surgery in the setting of chronic liver disease.

The association between non-alcoholic fatty liver disease (with or without metabolic syndrome) and extrahepatic cancer development

BACKGROUND AND AIM

This study was designed to determine whether non-alcoholic fatty liver disease (NAFLD), with or without metabolic syndrome (MetS), is a risk factor for cancer development.

METHODS

We conducted a retrospective longitudinal study at the Center for Preventive Medicine, St. Luke's International Hospital. Among all participants who underwent a health checkup between 2005 and 2019, cancer development tendencies were compared between those who were diagnosed with NAFLD and those who were not. Further evaluation was conducted among NAFLD-diagnosed participants with versus without MetS in the same manner. Those with a history of a specific liver disease, any type of cancer, or alcohol consumption in any amount at the time of the initial visit were excluded from the study.

RESULTS

Data were collected from 30 172 participants who underwent health checkups, among whom 4394 (14.6%) had NAFLD. Over the 14-year follow-up period, 2086 participants (6.9%) developed cancer. Participants with NAFLD had a higher incidence of digestive organ neoplasms (odds ratio [OR]: 1.34, 95% confidence interval [CI]: 1.07-1.67), especially in the stomach (OR: 1.40, 95% CI: 1.02-1.94) and small intestine (OR: 2.80, 95% CI: 0.87-8.96), than did those without NAFLD. Participants with NAFLD and MetS had significantly lower rates of neoplasms in respiratory and intrathoracic organs (OR: 0.35 95% CI: 0.14-0.88) and male genital organs (OR: 0.46 95% CI: 0.24-0.87) than did individuals without NAFLD.

CONCLUSIONS

Non-alcoholic fatty liver disease is associated with the development of gastrointestinal malignancies, while MetS is a negative risk factor for lung and prostate cancer.

Scoping Review and Meta-Analysis Suggests that Cannabis Use May Reduce Cancer Risk in the United States

Introduction: Cannabis smoke contains carcinogens similar to tobacco, in addition to compounds with antitumor activity. Cannabis use reduces the risk of obesity and cannabinoids inhibit chronic inflammation, known causes of cancer. The net effect of Cannabis use on cancer risk is not known. Objective: To examine the association between Cannabis use and cancer risk in the United States. Methods: Identify and analyze published data on cancer risk in Cannabis users. Results: A total of 55 data points, consisting of risk ratios of cancer in Cannabis users and nonusers, were identified from 34 studies. Of these, 5 did not contain data essential for inclusion in the meta-analysis. The remaining data showed a nonsignificant trend to an association with reduced risk (relative risk [RR]=0.90, p>0.06, N=50) although heterogeneity is high (I²=72.4%). Removal of data with high risk of selection bias (defined as those from North Africa and those that failed to adjust for tobacco) and data with high risk of performance bias (defined as those with fewer than 20 cases or controls among Cannabis users) resulted in an RR <1.0 (RR=0.86, p<0.017, N=24) and large effect size (Hedges g=0.66), but did not decrease heterogeneity (I²=74.9). Of all cancer sites, only testicular cancer showed an RR value >1, although this was not significant and had a negligible effect size (RR=1.12, p=0.3, Hedges g=0.02). Following removal of testicular cancers the remaining data showed a decrease in risk (RR=0.87, p<0.025, N=41). Cancers of the head and neck showed a negative association with cancer risk (RR=0.83, p<0.05), with a large effect size (Hedges g=0.55), but high heterogeneity (I²=79.2%). RR did not reach statistical significance in the remaining cancer site categories (lung, testicular, obesity-associated, other). The data are consistent with a negative association between Cannabis use and nontesticular cancer, but there is low confidence in this result due to high heterogeneity and a paucity of data for many cancer types.

Early age onset colorectal cancer

The incidence and mortality associated with colorectal cancer (CRC) diagnosed in patients under the age of 50 have been steadily increasing. The exact etiology of these epidemiologic trends is unclear. This chapter will provide a comprehensive review on the topic of early age onset colorectal cancer (EAO-CRC), defined as colorectal cancer (CRC) diagnosed in patients under the age of 50. Topics reviewed will include the epidemiology of EAO-CRC around the world, clinical and pathological features of EAO-CRC in contrast to later age onset CRC (CRC diagnosed on those over the age of 50) and the observed molecular and somatic characteristics. This chapter will review the etiologies to EAO-CRC and the established, as well as proposed risk factors for disease. Evidence-based approaches to prevention, early detection, treatment and survivorship will be presented.

Obesity and incident gastrointestinal cancers: overall body size or central obesity measures, which factor matters?

BMI does not reflect the location or amount of body fat. We aimed to investigate the role of general and central obesity measures in the prediction of incident gastrointestinal cancers. In this analysis of the Golestan Cohort Study, we included 47 586 cancer-free individuals followed for 12.3 years (IQR: 10.5-13.2). We investigated the association of obesity measures including BMI, waist circumference and waist-to-hip ratio (WHR) at enrollment and the incidence of esophageal, gastric, colorectal and pancreatic cancers. Cox proportional hazard models were used to estimate the association between covariates and gastrointestinal cancer risk. We observed no significant associations between obesity measures and incidence of the above-mentioned gastrointestinal cancers in men. In women, BMI, waist circumference and WHR were associated with significant reductions in the risk of esophageal squamous cell carcinoma (ESCC): hazard ratio (HR): 0.67 [95% confidence interval (CI): 0.56-0.81], HR: 0.71 (95% CI: 0.60-0.84) and HR: 0.80 (95% CI: 0.68- 0.94), respectively. In addition, WHR was associated with significantly increased risks for colorectal cancer (HR: 1.39, 95% CI: 1.08-1.78) and gastric cancer (HR: 1.24, 95% CI: 1.01-1.51) in women. In this study, statistically significant associations between obesity measures and incident esophageal, gastric and colorectal cancers were seen in women.

Impact of Body Weight Gain on the Incidence of Nonalcoholic Fatty Liver Disease in Nonobese Japanese Individuals

INTRODUCTION

We aimed to investigate the effect of recent short-term weight gain on the incidence of nonalcoholic fatty liver disease (NAFLD) in nonobese (body mass index < 25 kg/m) participants.

METHODS

This retrospective cohort study included nonobese individuals who participated in an annual health checkup between 2008 and 2018 in Tokyo, Japan. We estimated the multivariable adjusted hazard ratio for the development of NAFLD diagnosed via ultrasound after a 3-kg unit gain in weight measured at a 2-year landmark time point postbaseline. Multivariable adjustments included weight change from the age of 20 and other relevant confounding factors. Sensitivity analyses using additional landmark time points at 1, 3, 4, and 5 years postbaseline and time-dependent Cox proportional hazards regressions were performed.

RESULTS

Among the 27,064 nonobese participants (142,699 person years of follow-up), 2,895 were diagnosed with NAFLD. Approximately 90% of the patients with NAFLD maintained their nonobese status before disease diagnosis. The adjusted hazard ratio for the development of NAFLD (for a 3-kg unit of weight gain) at the 2-year landmark time point postbaseline was 1.60 (95% confidence interval, 1.46-1.76) in nonobese men and 1.66 (95% confidence interval, 1.51-1.83) in nonobese women. This association was maintained in the sensitivity analyses.

DISCUSSION

Recent short-term weight gain is an independent risk factor for NAFLD development in nonobese men and women. Clinicians should be mindful of the association between weight gain and NAFLD onset, even in the nonobese population.

Diet and cancer of the esophagus and stomach

PURPOSE OF REVIEW

Dietary factors have been linked to cancers. This review focuses on several nutrients, which have strong evidence showing increase in cancer risks in the esophagus and stomach.

RECENT FINDINGS

Obesity is an important risk factor in upper gastrointestinal cancers. High sugar content in food and sugary drinks are the main drivers of obesity. Proinflammatory diet is another dietary factor, which is increasingly recognized as being associated with esophageal and gastric cancer.

SUMMARY

Cancer has been predicted to be the leading cause of death in this century. Cancers of the esophagus and stomach are the six and third most common cause of death worldwide. Although Helicobacter pylori infection is a known cause of gastric cancer, obesity is a leading contributor to esophageal adenocarcinoma. Epidemiological data have shown that dietary factors are associated with the two cancers. Observational, case control, animal and recent large cohort studies have identified associations between dietary factors and upper gastrointestinal cancer. Data are also emerging from studies, which look at dietary patterns, such as reduction in the Dietary Inflammatory Index, as well as adherence to a modified Mediterranean diet, and its association with the incidence of esophageal and gastric cancer.

Molecular Mechanisms Linking Nonalcoholic Steatohepatitis to Cancer

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High risk of colorectal polyps in men with non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND AND AIM

This meta-analysis aims to explore the risk of colorectal polyps among non-alcoholic fatty liver disease (NAFLD) patients.

METHODS

We searched PubMed, EMBASE, and Cochrane library databases using predefined search term to identify eligible studies (published up to 7 November 2019). Data from selected studies were extracted by using a standardized information collection form, and meta-analyses were performed using random-effects model. The statistical heterogeneity among studies (I² ), subgroup analyses, meta-regression analyses, and the possibility of publication bias were assessed.

RESULTS

Twenty observational (12 cross-sectional, two case-control, and six cohort) studies met the eligibility criteria, involving 142 387 asymptomatic adults. In cross-sectional/case-control studies, NAFLD was found to be associated with an increased risk of colorectal polyps (odds ratio [OR] = 1.34; 95% confidence interval [CI] = 1.23-1.47) (including unclassified colorectal polyps, hyperplastic polyps, adenomas, and cancers) with statistically significant heterogeneity (I²  = 67.8%; P < 0.001). NAFLD was also associated with a higher risk of incident colorectal polyps (hazard ratio = 1.60; 95% CI = 1.36-1.87) with low heterogeneity (I²  = 21.8%; P = 0.263) in longitudinal studies. The severity of NAFLD was associated with a higher risk of colorectal adenomas (OR = 1.57; 95% CI = 1.30-1.88), but not colorectal cancer (OR = 1.37; 95% CI = 0.92-2.03). The subgroup analysis according to gender showed that NAFLD was significantly associated with a higher risk of colorectal polyps in the male population without significant heterogeneity (OR = 1.47; 95% CI = 1.29-1.67, I²  = 0%), but not in the female population (OR = 0.88; 95% CI = 0.60-1.29, I²  = 34.2%).

CONCLUSIONS

NAFLD was associated with an increased risk of colorectal polyps. There was a significant difference of the relationship between genders, which suggested more precise screening colonoscopy recommendation in NAFLD patients according to gender.

Complications of Non-Alcoholic Fatty Liver Disease in Extrahepatic Organs

Non-alcoholic fatty liver disease (NAFLD) is now recognized as the most common chronic liver disease worldwide, along with the concurrent epidemics of metabolic syndrome and obesity. Patients with NAFLD have increased risks of end-stage liver disease, hepatocellular carcinoma, and liver-related mortality. However, the largest cause of death among patients with NAFLD is cardiovascular disease followed by extrahepatic malignancies, whereas liver-related mortality is only the third cause of death. Extrahepatic complications of NAFLD include chronic kidney disease, extrahepatic malignancies (such as colorectal cancer), psychological dysfunction, gastroesophageal reflux disease, obstructive sleep apnea syndrome, periodontitis, hypothyroidism, growth hormone deficiency, and polycystic ovarian syndrome. The objective of this narrative review was to summarize recent evidences about extrahepatic complications of NAFLD, with focus on the prevalent/incident risk of such diseases in patients with NAFLD. To date, an appropriate screening method for extrahepatic complications has not yet been determined. Collaborative care with respective experts seems to be necessary for patient management because extrahepatic complications can occur across multiple organs. Further studies are needed to reveal risk profiles at baseline and to determine an appropriate screening method for extrahepatic diseases.

Complications, morbidity and mortality of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized public health problem, affecting up to a quarter of the world's adult population. The burden of NAFLD is influenced by the epidemics of obesity and type 2 diabetes mellitus (T2DM) and the prevalence of these conditions is not expected to decrease in the forthcoming decades. Consequently, the burden of NAFLD-related liver complications (non-alcoholic steatohepatitis [NASH], cirrhosis and hepatocellular carcinoma) and the need for life-saving liver transplantation are also expected to increase further in the near future. A large body of clinical evidence indicates that NAFLD is associated not only with increased liver-related morbidity and mortality, but also with an increased risk of developing other important extra-hepatic diseases, such as cardiovascular disease (that is the predominant cause of death in patients with NAFLD), extra-hepatic cancers (mainly colorectal cancers), T2DM and chronic kidney disease. Thus, NAFLD creates a considerable health and economic burden worldwide and often results in poor quality of life. This narrative review provides an overview of the current literature on main complications, morbidity and mortality of this common and burdensome liver disease.

Optimizing patients with non-alcoholic fatty liver disease pre-transplant

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries. Non-alcoholic steatohepatitis (NASH), which is the progressive counterpart of the disease, is becoming the leading indication for liver transplantation in North America. Owing to the lack of symptoms, NASH is often an incidental diagnosis, resulting in a significant proportion of patients being diagnosed when advanced liver disease has already developed. NAFLD has recently been characterized as the hepatic manifestation of metabolic syndrome. Consequently, it is a multisystem disease that often co-exists with several other conditions, such as obesity, diabetes, cardiovascular diseases, and extra-hepatic malignancy, which have an impact on selection of transplant recipients. The complexity of diagnostic approach, need for multidisciplinary clinical management, and lack of a specific treatment further complicate the picture of this extremely prevalent liver condition. NAFLD patients with advanced liver disease should be considered for early referral to liver transplant clinics for careful metabolic and cardiovascular risk stratification because they have worse survival rates after liver transplantation than other patients with chronic liver disease. Early referral will also facilitate optimization of metabolic comorbidities before proceeding with transplantation. This review provides an overview of strategies to identify patients with advanced NAFLD, with an emphasis on the management of associated comorbidities and optimal timing of pre-transplant evaluation. Other topics that have been shown to affect recipient optimization, such as the role of lifestyle changes and bariatric surgery in the management of obesity, as well as sarcopenia in decompensated NASH-related cirrhosis, are addressed.

Investigation of Leptin and its receptor (LEPR) for single nucleotide polymorphisms in colorectal cancer: a case-control study involving 2,306 subjects

Single nucleotide polymorphisms (SNPs) in the genes coding for leptin (LEP) and its receptor (LEPR) might regulate energy balance and be implicated in the development of colorectal cancer (CRC). In the present investigation, 1,003 CRC cases and 1,303 matched controls was compared. Five functional SNPs in LEP and LEPR genes were chosen to evaluate the correlation of these chosen SNPs with CRC susceptibility. We used the SNPscan^TM genotyping assay to genotype LEP and LEPR SNPs. A significantly decreased risk of CRC was found to be associated with the LEPR rs6588147 polymorphism (GA vs. GG: crude P=0.007 and GA/AA vs. GG: crude P=0.018). With adjustments for risk factors (e.g. age, gender, drinking, BMI and smoking), these associations were not changed. In subgroup analyses, the association of LEP rs2167270 with a decreased risk of CRC was found in the ≥61 years old subgroup. For LEPR rs1137100, the association of this SNP with an increased susceptibility of CRC was found in the BMI <24 kg/m² subgroup. In subgroup analyses for LEPR rs6588147, we identified that this locus also decreased the susceptibility of CRC in the male subgroup, <61 years old subgroup, never smoking subgroup and never drinking subgroup. For LEPR rs1137101, the relationship of this polymorphism with a decreased susceptibility to CRC was found in the never drinking subgroup. In summary, the present study highlights that LEPR rs6588147, rs1137101 and LEP rs2167270 may decrease the risk of CRC. However, LEPR rs1137100 is associated with susceptibility to CRC. Further case-control studies with larger sample sizes should be conducted to validate our findings.

Association between nonalcoholic fatty liver disease and extrahepatic cancers: a systematic review and meta-analysis

BACKGROUND

NAFLD is tightly associated with various diseases such as diabetes, cardiovascular disease, kidney disease, and cancer. Previous studies had investigated the association between NAFLD and various extrahepatic cancers, but the available data to date is not conclusive. The aim of this study was to investigate the association between NAFLD and various extrahepatic cancers comprehensively.

METHODS

Searches were conducted of various electronic databases (PubMed, EMBASE, Medline, and the Cochrane Library) to identify observational studies published between 1996 and January 2020 which investigated the association between NAFLD and extrahepatic cancers. The pooled OR/HR/IRR of the association between NAFLD and various extrahepatic cancers were analyzed.

RESULTS

A total of 26 studies were included to investigate the association between NAFLD and various extrahepatic cancers. As the results shown, the pooled OR values of the risk of colorectal cancer and adenomas in patients with NAFLD were 1.72 (95%CI: 1.40-2.11) and 1.37 (95%CI: 1.29-1.46), respectively. The pooled OR values of the risk of intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma in patients with NAFLD were 2.46 (95%CI: 1.77-3.44) and 2.24 (95%CI: 1.58-3.17), respectively. The pooled OR value of the risk of breast cancer in patients with NAFLD was 1.69 (95%CI: 1.44-1.99). In addition, NAFLD was also tightly associatied with the risk of gastric cancer, pancreatic cancer, prostate cancer, and esophageal cancer.

CONCLUSIONS

NAFLD could significantly increase the development risk of colorectal adenomas and cancer, intrahepatic and extrahepatic cholangiocarcinoma, breast, gastric, pancreatic, prostate, and esophageal cancer. NAFLD could be considered as one of the influencing factors during the clinical diagnosis and treatment for the extrahepatic cancers.

Nonalcoholic Fatty Liver Disease 2020: The State of the Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease, with a worldwide prevalence of 25%. In the United States, NAFLD and its subtype, nonalcoholic steatohepatitis, affect 30% and 5% of the population, respectively. Considering the ongoing obesity epidemic beginning in childhood, the rise in diabetes, and other factors, the prevalence of NAFLD along with the proportion of those with advanced liver disease is projected to continue to increase. This will have an important impact on public health reflected in health care costs, including impact on the need for liver transplantation, for which nonalcoholic steatohepatitis is already close to becoming the most common indication. NAFLD patients with evidence of nonalcoholic steatohepatitis and advanced fibrosis are at markedly increased risk of adverse outcomes, including overall mortality, and liver-specific morbidity and mortality, respectively. Identification of this cohort of NAFLD patients is paramount, given the associated poorer outcomes, in order to target resources to those who need it most. Various noninvasive tools have been developed in this regard. This review provides an update on the epidemiology, clinical and prognostic features, and diagnostic approach to patients with NAFLD.

Impact of metabolically healthy obesity on the risk of incident gastric cancer: a population-based cohort study

BACKGROUND

The risk of colon or breast cancer in metabolically healthy obese (MHO) were lower than that in metabolically abnormal obese (MAO). We hypothesized that the risk of incident gastric cancer in MHO is lower than that in MAO.

METHODS

This historical cohort study included 19,685 Japanese individuals who received health-checkup programs from 2003 to 2016. Each subject was classified as metabolically healthy (MH) (no metabolic abnormalities) or metabolically abnormal (MA) (one or more metabolic abnormalities), according to four metabolic factors (hypertension, impaired fasting glucose, hypertriglyceridemia and low HDL-cholesterol). Obese (O) or non-obese (NO) was classified by a BMI cutoff of 25.0 kg/m². Hazard ratios of metabolic phenotypes for incident gastric cancer were calculated by the Cox proportional hazard model with adjustments for age, sex, alcohol consumption, smoking and exercise.

RESULTS

Over the median follow-up period of 5.5 (2.9-9.4) years, incident rate of gastric cancer was 0.65 per 1000 persons-years. Incident rate of MHNO, MHO, MANO and MAO were 0.33, 0.25, 0.80 and 1.21 per 1000 persons-years, respectively. Compared with MHNO, the adjusted hazard ratios for development of gastric cancer were 0.69 (95% CI 0.04-3.39, p = 0.723) in MHO, 1.16 (95% CI 0.63-2.12, p = 0.636) in MANO and 2.09 (95% CI 1.10-3.97, p = 0.024) in MAO.

CONCLUSIONS

This study shows that individuals with MAO, but not those with MHO, had an elevated risk for incident gastric cancer. Thus, we should focus more on the presence of metabolic abnormalities rather than obesity itself for incident gastric cancer.