Increased risk of colorectal polyps in patients with non-alcoholic fatty liver disease undergoing liver transplant evaluation

Nonalcoholic or metabolic-associated fatty liver disease and colorectal polyps: evidence from meta-analysis and two-sample Mendelian randomization

Introduction

Nonalcoholic or metabolism-associated fatty liver disease (NAFLD or MAFLD) and colorectal polyps are chronic conditions strongly linked to lifestyle factors. However, the precise causal link between NAFLD or MAFLD and the development of colorectal polyps is not yet fully understood. This study aimed to evaluate the association between NAFLD or MAFLD and the risk of colorectal polyps based on a meta-analysis and two-sample Mendelian randomization (MR) analyses.

Methods

PubMed, Embase, Cochrane Library databases were searched for eligible studies to be included in the meta-analysis. We conducted a thorough search of the PubMed, Embase, and Cochrane Library databases to identify eligible studies prior to 22 March 2024. Subgroup analyses were performed based on sex, age, and geographical region. Causality between NAFLD/MAFLD and colorectal polyps was explored by using two-sample Mendelian randomization (MR) analyses.

Results

Based on an analysis of 17 studies encompassed within this meta-analysis, a significant correlation was identified between the presence of NAFLD/MAFLD and elevated incidence of colorectal polyps (NAFLD: OR = 1.57, 95% CI: 1.43-1.73, I2 = 38%, p = 0.06; MAFLD: OR = 1.67, 95% CI: 1.40-2.00, I2 = 77%, p = 0.002). However, current evidence does not support a causal relationship between NAFLD/MAFLD and the prevalence of colorectal polyps (OR = 0.9998315, 95% CI: 0.9987566-1.000907, P = 0.7587638).

Conclusion

NAFLD/MAFLD demonstrated a significant positive correlation with an elevated risk of developing colorectal polyps. However, the MR analysis suggested that no causal relationship existed between NAFLD/MAFLD and colorectal polyps. Therefore, further research is required to identify the underlying mechanism of causal link between these diseases.

MAFLD with central obesity is associated with increased risk of colorectal adenoma and high-risk adenoma

OBJECTIVE

To analyze the risk factors associated with colorectal adenoma and to investigate the associations of metabolism-related fatty liver disease (MAFLD) with obesity, colorectal adenoma and high-risk adenoma.

METHODS

A total of 1395 subjects were enrolled and divided into a colorectal adenoma group (593 subjects) and a control group (802 subjects) according to the inclusion and exclusion criteria. The characteristics of patients in the colorectal adenoma group and the control group were compared by the chi-square test. Univariate and multivariate logistic analyses were used to analyze independent risk factors and associations with different MAFLD subtypes. Colorectal adenoma characteristics and the proportion of patients with high-risk colorectal adenoma were also compared.

RESULTS

High-density lipoprotein (HDL-C) was significantly lower in patients in the colorectal adenoma group than in those in the control group (P < 0.001). Logistic regression analysis revealed that age, obesity status, central obesity status, hypertension status, diabetes status, fatty liver status, smoking history, BMI, waist circumference, triglyceride level, HDL-C level, fasting blood glucose level and degree of hepatic steatosis were all independent risk factors for colorectal adenoma. Notably, MAFLD was associated with a significantly increased risk of colorectal adenoma in patients with central obesity (P < 0.001). In addition, obesity, central obesity, diabetes, fatty liver and degree of hepatic steatosis were all shown to be independent risk factors for high-risk colorectal adenoma. In addition, a greater proportion of MAFLD patients with central obesity than those without central obesity had high-risk colorectal adenoma.

CONCLUSION

MAFLD and central obesity are independently associated with the development of colorectal adenoma. MAFLD with central obesity is associated with an increased risk of colorectal adenoma and high-risk adenoma.

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.

The Troubling Link Between Non-alcoholic Fatty Liver Disease (NAFLD) and Extrahepatic Cancers (EHC)

Non-alcoholic fatty liver disease (NAFLD) is a fast-spreading epidemic across the globe and has serious implications far beyond that of a "benign" liver condition. It is usually an outcome of ectopic fat storage due to chronic positive energy balance leading to obesity and is associated with multiple health problems. While association with cardiovascular disease and hepatocellular cancer is well recognized, it is becoming clear the NAFLD carries with it an increased risk of cancers of extrahepatic tissues. Studies have reported a higher risk for cancers of the colon, breast, prostate, lung, and pancreas. Fatty liver is associated with increased mortality; there is an urgent need to understand that fatty liver is not always benign, and not always associated with obesity. It is, however, a reversible condition and early recognition and intervention can alter its natural history and associated complications.

Molecular Aspects of Colorectal Adenomas: The Interplay among Microenvironment, Oxidative Stress, and Predisposition

The development of colorectal cancer (CRC) is a multistep process initiated by a benign polyp that has the potential to evolve into in situ carcinoma through the interactions between environmental and genetic factors. CRC incidence rates are constantly increased for young adult patients presenting an advanced tumor stage. The majority of CRCs arise from colonic adenomas originating from aberrant cell proliferation of colon epithelium. Endoscopic polypectomy represents a tool for early detection and removal of polyps, although the occurrence of cancers after negative colonoscopy shows a significant incidence. It has long been recognized that the aberrant regulation of Wingless/It (Wnt)/β-Catenin signaling in the pathogenesis of colorectal cancer is supported by its critical role in the differentiation of stem cells in intestinal crypts and in the maintenance of intestinal homeostasis. For this review, we will focus on the development of adenomatous polyps through the interplay between renewal signaling in the colon epithelium and reactive oxygen species (ROS) production. The current knowledge of molecular pathology allows us to deepen the relationships between oxidative stress and other risk factors as lifestyle, microbiota, and predisposition. We underline that the chronic inflammation and ROS production in the colon epithelium can impair the Wnt/β-catenin and/or base excision repair (BER) pathways and predispose to polyp development. In fact, the coexistence of oxidative DNA damage and errors in DNA polymerase can foster C>T transitions in various types of cancer and adenomas, leading to a hypermutated phenotype of tumor cells. Moreover, the function of Adenomatous Polyposis Coli (APC) protein in regulating DNA repair is very important as therapeutic implication making DNA damaging chemotherapeutic agents more effective in CRC cells that tend to accumulate mutations. Additional studies will determine whether approaches based on Wnt inhibition would provide long-term therapeutic value in CRC, but it is clear that APC disruption plays a central role in driving and maintaining tumorigenesis.

Extrahepatic Malignancies in Nonalcoholic Fatty Liver Disease

PURPOSE OF REVIEW

Malignancy is the second most common cause of death in individuals with nonalcoholic fatty liver disease (NAFLD). Understanding unique characteristics of malignancy risk beyond hepatocellular carcinoma in NAFLD has significant implications in counseling and personalized preventative measures in this high-risk population. Herein, we systematically review the literature reporting extra-hepatic malignancies in NAFLD and discuss the key biological mechanisms underpinning the association between excess adiposity and cancer risk.

RECENT FINDINGS

Several studies have shown significant associations between NAFLD and extrahepatic malignancies. The strongest association was found with cancers of the gastrointestinal tract and hormone-sensitive cancers. Recent data support sex-specific differences in cancer risk increase in NAFLD: colorectal cancer in men and uterine cancer in women. The risk of cancer development is higher in NAFLD than obesity alone.

SUMMARY

A growing body of observational evidence over the last decade supports the association between NAFLD and extrahepatic malignancies. This association requires further studies, ideally designed to include more detailed measures of body fat deposition beyond BMI in well-characterized, large cohorts of NAFLD patients, to determine if screening policies should be individualized in this group.

Magnitude of Nonalcoholic Fatty Liver Disease: Western Perspective

The incidence of nonalcoholic fatty liver disease (NAFLD) is continuing to rise worldwide, and it is estimated that this disquieting trend will continue for another 10-15 years before prevalence begins to decrease. NAFLD is the hepatic manifestation of metabolic syndrome. As obesity, diabetes, and other lifestyle-related diseases continue to rise, the spectrum of NAFLD, e.g., nonalcoholic steatohepatitis, liver fibrosis, liver cirrhosis, liver-related morbidity, and mortality, will increase in parallel. Its widespread prevalence and associated economic burden have drawn significant attention, and a multitude of pharmaceutical companies are participating in active research trying to find a "cure". Unfortunately, as of now, no targeted treatment exists to treat this condition, and therefore, emphasis has been on its prevention. The current review focuses on the epidemiology, clinical characteristics, risk factors, and clinical outcomes of NAFLD in Western countries. It is important to understand the magnitude of NAFLD and its risk factors in Western countries where the prevalence of NAFLD has now reached epidemic proportions to identify the best strategy to prevent and possibly control this epidemic.

Chronic liver disease promotes lesions of the colorectal adenoma-carcinoma sequence, independent of liver cirrhosis

Background

Research increasingly focuses on identifying individuals at greater risk of colorectal cancer (CRC) to enhance colonoscopy screening efficacy.

Objective

The objective of this article is to determine associations between chronic liver disease and lesions along the colorectal adenoma-carcinoma sequence.

Methods

This retrospective study encompasses consecutive liver disease patients (LDPs) of all etiologies evaluated for liver transplantation at a single institution and a control group of liver-healthy patients (LHPs) undergoing colonoscopy as part of the German CRC screening program.

Rates of polyps, adenomas, high-risk situations (HRS) and CRC were analyzed in univariable and multivariable settings adjusting for age, gender, body mass index and number of colonoscopies. Differences between LHPs and LDPs and between cirrhotic and noncirrhotic hepatopathy were assessed.

Results

In total, 1046 patients (52.6% male, median age 59.6 years) were included, of whom 38.9% had liver disease. A total of 41.0% of all patients showed polyps, 23.2% adenomas, 10.0% HRS, and 0.5% CRC. LDPs were more likely to develop polyps, adenomas and HRS than LHPs, both in univariable and multivariable analysis. There were no significant differences between cirrhotic and noncirrhotic patients.

Conclusion

Chronic liver disease of any etiology is associated with colonic lesions of the colorectal adenoma-carcinoma sequence, independent of cirrhosis. LDPs should receive intensified, and earlier, colonoscopy screening.

Portal Hypertensive Polyposis in Advanced Liver Cirrhosis: The Unknown Entity?

BACKGROUND

Portal hypertension is a serious complication of liver cirrhosis.

OBJECTIVE

To identify relevant endoscopic findings in patients with advanced cirrhosis and consecutive portal hypertension.

METHODS

This was a retrospective study of liver transplant candidates who underwent upper gastrointestinal endoscopy between April 2011 and November 2015.

RESULTS

A total of 1,045 upper endoscopies were analyzed. Portal hypertensive gastric and duodenal polyps were frequently observed and were associated with thrombocytopenia (p = 0.040; OR: 2.4, 95% CI 1.04-5.50), Child-Pugh score > 6 (p = 0.033; OR: 2.3, 95% CI 1.07-4.92), Model for End Stage Liver Disease score > 16 (p = 0.030; OR: 4.1, 95% CI 1.14-15.00), and previous rubber band ligation (p < 0.001; OR = 5.2, 95% CI 2.5-10.7). These polyps often recurred after polypectomy; however, no malignant transformation occurred during the observational time until October 2017. The most common endoscopic finding was esophageal varices, observed in more than 90% of patients.

CONCLUSION

Portal hypertensive polyposis is common in patients with advanced cirrhosis. Our data suggest that these polyps have benign characteristics.

Underrated enemy - from nonalcoholic fatty liver disease to cancers of the gastrointestinal tract

Nonalcoholic fatty liver disease (NAFLD) is intrahepatic ectopic lipid deposition which is present despite a lack of other causes of secondary hepatic fat accumulation. It is the most common chronic liver disorder in the welldeveloped countries. NAFLD is a multidisciplinary disease that affects various systems and organs and is inextricably linked to simple obesity, metabolic syndrome, insulin resistance and overt diabetes mellitus type 2. The positive energy balance related to obesity leads to a variety of systemic changes including modified levels of insulin, insulin- like growth factor-1, adipokines, hepatokines and cytokines. It is strongly linked to carcinogenesis and new evidence proves that NAFLD is associated with higher risk of all-cause mortality and cancer-specific mortality among cancer survivors. This article focuses on the association between NAFLD and extrahepatic gastrointestinal tract cancers, aiming to shed light on the pathomechanism of changes leading to the development of tumors.

Alcoholic liver disease is a strong predictor of colorectal polyps in liver transplant recipients

BACKGROUND AND AIMS

 Colorectal cancer (CRC) is associated with a significantly reduced survival rate in transplant recipients. The prevalence and risk factors of CRC and of colorectal polyps after orthotopic liver transplant (OLT) remain unclear. The study aim was to determine the prevalence of colorectal polyps in OLT recipients. A secondary objective was to explore possible risk factors of polyps.

PATIENTS AND MATERIALS

 This was a retrospective single center study of all OLT recipients transplanted between 2007 and 2009. All patients who underwent a colonoscopy 5 ± 5 years after OLT were included. The outcome was colorectal polyps, as identified on colonoscopy. A logistic regression model was performed to identify potential predictors of polyps.

RESULTS

 Of 164 OLT recipients, 80 were included in this study. Polyps were diagnosed in 37 % of patients before transplant and in 33 % afterwards. With regard to post-transplant lesions, 22 % were advanced adenomas or cancerous. In the regression analysis, the odds of post-transplant polyps were 11 times higher in patients with alcoholic liver disease (OR 11.3, 95 %CI 3.2 - 39.4; P  < 0.001).

CONCLUSION

 Patients with end-stage liver disease may be at high risk of colorectal polyps before and after liver transplant, and screening should be continued in both contexts. Those with alcoholic liver disease are particularly at risk for post-OLT polyps and may benefit from more intensive screening.

Non-Alcoholic Fatty Liver Disease and Extra-Hepatic Cancers

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease but the second cause of death among NAFLD patients are attributed to malignancies at both gastrointestinal (liver, colon, esophagus, stomach, and pancreas) and extra-intestinal sites (kidney in men, and breast in women). Obesity and related metabolic abnormalities are associated with increased incidence or mortality for a number of cancers. NAFLD has an intertwined relationship with metabolic syndrome and significantly contributes to the risk of hepatocellular carcinoma (HCC), but recent evidence have fuelled concerns that NAFLD may be a new, and added, risk factor for extra-hepatic cancers, particularly in the gastrointestinal tract. In this review we critically appraise key studies on NAFLD-associated extra-hepatic cancers and speculate on how NAFLD may influence carcinogenesis at these sites.