The association between nonalcoholic fatty liver disease and risk of colorectal adenoma and cancer incident and recurrence: a meta-analysis of observational studies

Non-Alcoholic Fatty Liver Disease May Be a Risk Factor for Liver Metastasis After Radical Surgery for Colorectal Cancer: A Retrospective Study

PURPOSE

Distant metastasis develops in approximately one-third of patients with colorectal cancer (CRC) who undergo radical surgery, and colorectal liver metastasis (CRLM) is the most common form of distant metastasis in CRC. Hepatectomy is the only potentially curative treatment for CRLM, but few patients with metastatic CRC meet the criteria for this radical resection, and the 5-year survival rate is poor. Identifying risk factors for CRLM is critical. Non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for CRC. However, the effect of NAFLD on CRC liver metastasis after radical surgery remains unclear. Therefore, we examined the impact of NAFLD-associated hepatic fibrosis on liver metastasis after radical surgery for CRC.

METHODS

We retrospectively analyzed data from 388 patients who underwent curative surgery for CRC at our hospital between April 2008 and March 2015. The patients' clinical results, surgical procedures, postoperative course, and pathological and survival data were collected from the hospital records. The NAFLD fibrosis score was calculated and used to divide the patients into two groups (NAFLD and non-NAFLD).

RESULTS

Recurrence was observed in 83/388 (21.4%) patients after a mean follow-up of 65.6 ± 15.1 months. Twenty-five patients had liver metastasis: 8 in the NAFLD group (8/45; 17.8%) and 17 in the non-NALFD group (17/343; 5.0%) (p = 0.004). Liver metastasis-free survival was significantly worse in the NAFLD than non-NAFLD group (p < 0.001). NAFLD and cancer stage were independent risk factors for liver metastasis recurrence.

CONCLUSION

NAFLD may be a risk factor for liver metastasis in patients with CRC who undergo curative surgery.

Identification of Predictors of Non-alcoholic Steatohepatitis and Its Severity in Individuals Undergoing Bariatric Surgery

BACKGROUND

As obesity reached epidemic proportions, non-alcoholic fatty liver disease (NAFLD) also had a worrisome parallel increase. The non-invasive differentiation of non-alcoholic steatohepatitis (NASH) from uncomplicated NAFLD remains an important challenge in current clinical practice.

OBJECTIVE

To identify predictors of the occurrence and severity of NAFLD and NASH.

METHODS

This is an analytical cross-sectional study which included individuals undergoing bariatric surgery. Participants were histologically classified according to the presence NASH and severity of NAFLD. Demographic, clinical, anthropometric, and biochemical aspects were analyzed and compared.

RESULTS

Out of 171 individuals, 87.7% were female and the mean age was 38.4±9.3 years. The average BMI was 38±3.0 kg/m2. NAFLD was histologically confirmed in 74.9%; the commonest histopathological abnormalities were macrovesicular steatosis (74.9%) and ballooning (40.4%). Simple steatosis occurred in 30.4%, 44.4% presented with NASH, and 31% had severe NAFLD. NASH associated with higher levels of ALT (0.03), ALP (0.02), and glucose (0.02). Cutoff values were, respectively, 23 U/L, 67 U/L, and 81 mg/dL. Their concomitant use provided an 83.1% specificity for NASH. Severe NAFLD associated with diabetes (p=0.02), higher BMI (p=0.01), AST (p=0.04), ALT (p<0.01), ALP (p=0.01), glucose (p=0.02), and ferritin (p<0.01). BMI over 39.3 kg/m2 and ferritin over 178 ng/mL concomitantly provided a 70.5% accuracy for severe NAFLD.

CONCLUSIONS

NASH and severe NAFLD associated with higher levels of ALT, ALP, and glucose. Severe NAFLD associated with higher BMI and higher ferritin levels in this group. The concomitant evaluation of these laboratory tests could help ruling out NASH and safely screening severe NAFLD.

Metabolic-associated fatty liver disease is associated with colorectal adenomas in young and older Korean adults

BACKGROUND AND AIMS

Given that the majority of colorectal cancers (CRCs) develop from high-risk adenomas, identifying risk factors for high-risk adenomas is important. The relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and the risk of colorectal adenoma in young adults remains unclear. We aimed to evaluate this relationship in adults <50 (younger) and ≥50 (older) years of age.

METHODS

This cross-sectional study included 184 792 Korean adults (80% <50 years of age) who all underwent liver ultrasound and colonoscopy. Participants were grouped into those with and without MAFLD and classified by adenoma presence into no adenoma, low-risk adenoma, or high-risk adenoma (defined as ≥3 adenomas, any ≥10 mm, or adenoma with high-grade dysplasia/villous features).

RESULTS

The prevalence of low- and high-risk adenomas among young and older adults was 9.6% and 0.8% and 22.3% and 4.8%, respectively. MAFLD was associated with an increased prevalence of low- and high-risk adenomas in young and older adults. Young adults with MAFLD had a 1.30 (95% CIs 1.26-1.35) and 1.40 (1.23-1.59) times higher prevalence of low- and high-risk adenomas, respectively, compared to those without MAFLD. These associations were consistent even in lean adults (BMI < 23 kg/m2 ) and those without a family history of CRC.

CONCLUSIONS

MAFLD is associated with an increased prevalence of low- and high-risk adenomas in Korean adults, regardless of age or obesity status. Whether reducing metabolic risk factors, such as MAFLD, reduces the risk of precancerous lesions and ultimately reduces the risk of early-onset CRC requires further investigation.

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

BACKGROUND AND AIM

Worldwide, colorectal cancer (CRC) is the third most common cancer and ranks second among the leading causes of cancer death. This study aims to devise and validate a scoring system based on metabolic parameters to predict the risk of advanced colorectal neoplasia (ACN) in a large Chinese population.

METHODS

This was a cohort study of 495 584 symptomatic subjects aged 40 years or older who have received colonoscopy in Hong Kong from 1997 to 2017. The algorithm's discriminatory ability was evaluated as the area under the curve (AUC) of the mathematically constructed receiver operating characteristic curve.

RESULTS

Age, male gender, inpatient setting, abnormal aspartate transaminase/alanine transaminase, white blood cell, plasma gamma-glutamyl transferase, high-density lipoprotein cholesterol, triglycerides, and hemoglobin A1c were significantly associated with ACN. A scoring of < 2.65 was designated as "low risk (LR)." Scores at 2.65 or above had prevalence higher than the overall prevalence and hence were assigned as "high risk (HR)." The prevalence of ACN was 32% and 11%, respectively, for HR and LR groups. The AUC for the risk score in the derivation and validation cohort was 70.12%.

CONCLUSIONS

This study has validated a simple, accurate, and easy-to-use scoring algorithm, which has a high discriminatory capability to predict ACN in symptomatic patients. Future studies should examine its predictive performance in other population groups.

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.

Artificial intelligence in nonalcoholic fatty liver disease

Background

Nonalcoholic fatty liver disease (NAFLD) has led to serious health-related complications worldwide. NAFLD has wide pathological spectra, ranging from simple steatosis to hepatitis to cirrhosis and hepatocellular carcinoma. Artificial intelligence (AI), including machine learning and deep learning algorithms, has provided great advancement and accuracy in identifying, diagnosing, and managing patients with NAFLD and detecting squeal such as advanced fibrosis and risk factors for hepatocellular cancer. This review summarizes different AI algorithms and methods in the field of hepatology, focusing on NAFLD.

Methods

A search of PubMed, WILEY, and MEDLINE databases were taken as relevant publications for this review on the application of AI techniques in detecting NAFLD in suspected population

Results

Out of 495 articles searched in relevant databases, 49 articles were finally included and analyzed. NASH-Scope model accurately distinguished between NAFLD and non-NAFLD and between NAFLD without fibrosis and NASH with fibrosis. The logistic regression (LR) model had the highest accuracy, whereas the support vector machine (SVM) had the highest specificity and precision in diagnosing NAFLD. An extreme gradient boosting model had the highest performance in predicting non-alcoholic steatohepatitis (NASH). Electronic health record (EHR) database studies helped the diagnose NAFLD/NASH. Automated image analysis techniques predicted NAFLD severity. Deep learning radiomic elastography (DLRE) had perfect accuracy in diagnosing the cases of advanced fibrosis.

Conclusion

AI in NAFLD has streamlined specific patient identification and has eased assessment and management methods of patients with NAFLD.

The molecular basis of the associations between non-alcoholic fatty liver disease and colorectal cancer

Background: Given the ongoing research on non-alcoholic fatty liver disease (NAFLD) and colorectal cancer (CRC), the number of studies suggesting a strong link between NAFLD and CRC is on the rise, while its underlying pathological mechanisms remain uncertain. This study aims to explore the shared genes and mechanisms and to reveal the molecular basis of the association between CRC and NAFLD through bioinformatics approaches. Methods: The Gene Expression Omnibus (GEO) dataset GSE89632 is downloaded for NAFLD cases and healthy controls. Additionally, the GSE4107 and GSE9348 datasets are obtained for CRC cases and healthy controls. Differentially expressed genes (DEGs) are obtained for NAFLD and CRC datasets, as well as shared genes between the two disorders. GO and KEGG enrichment analyses are further conducted. Subsequently, the STRING database and Cytoscape software are utilized to establish the PPI network and identify the hub genes. Then, co-expression analysis is performed using GeneMANIA. Subsequently, ROC curves and external datasets validation were applied to further screen the candidate markers. Finally, NetworkAnalyst is available as a means to construct a miRNA-gene regulatory network. Results: Under the threshold of FDR ≤ 0.01, 147 common genes are obtained in NAFLD and CRC. Categorization of GO functions shows that DEGs are predominantly enriched in "response to organic substance", "cellular response to chemical stimulus", and "response to external stimulus". The predominant KEGG pathways in DEGs are the "IL-17 signaling pathway", the "TNF signaling pathway", "Viral protein interaction with cytokine and cytokine receptor", "Cytokine-cytokine receptor interaction", and the "Toll-like receptor signaling pathway". Additionally, MYC, IL1B, FOS, CXCL8, PTGS2, MMP9, JUN, and IL6 are identified as hub genes by the evaluation of 7 algorithms. With the construction of miRNA-gene networks, 2 miRNAs, including miR-106a-5p, and miR-204-5p are predicted to be potential key miRNAs. Conclusion: This study identifies possible hub genes acting in the co-morbidity of NAFLD and CRC and discovers the interaction of miRNAs and hub genes, providing a novel understanding of the molecular basis for the relevance of CRC and NAFLD, thus contributing to the development of new therapeutic strategies to combat NAFLD and CRC.

Hepatocellular and extrahepatic cancers in non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Hepatocellular (HCC) and extrahepatic cancers have been associated with non-alcoholic fatty liver disease (NAFLD); however, the extent and nature of these relationships remain unclear. We aimed to estimate the absolute incidence rates of these cancers in adults with NAFLD with respect to key demographic and clinical factors.

METHODS

We searched PubMed, Embase, Cochrane Library and Web of Science databases for studies reporting the incidence rates of any cancer in adults with NAFLD from inception to 31 August 2020. The main meta-analysis outcomes were pooled incidences of cancers in NAFLD using random-effects modelling. Subgroup analyses examined the effects of NAFLD disease stage.

FINDINGS

In total, 64 studies were eligible for analysis of HCC and extrahepatic cancer incidence including 625,984 and 41,027 patients, respectively. The pooled HCC incidence rate was 1.25 per 1000 person-years (95% CI 1.01 to 1.49; I² = 94.8%). In patients with NAFLD with advanced liver fibrosis or cirrhosis, the HCC incidence rate was 14.46 per 1000 person-years (95% CI 10.89 to 18.04; I² = 91.3%). The pooled extrahepatic cancer incidence rate was 10.58 per 1000 person-years (95% CI 8.14 to 13.02; I² = 97.1%). The most frequently occurring extrahepatic cancers were uterine, breast, prostate, colorectal, and lung. Extrahepatic cancer incidence rates were not higher in patients with NAFLD with advanced liver fibrosis or cirrhosis.

INTERPRETATION

The rate of HCC development in patients with NAFLD who have progressed to advanced liver fibrosis or cirrhosis supports current HCC surveillance recommendations targeted for this group. Extrahepatic cancers are over eight-fold more frequent than HCC in NAFLD and not associated with liver fibrosis stage. As the global prevalence of NAFLD is approximately 25% and increasing, these findings support a focus on its prevention and the early detection of cancer in adults with NAFLD.

Association between the severity of metabolic dysfunction-associated fatty liver disease and the risk of colorectal neoplasm: a systematic review and meta-analysis

Background

The severity of metabolic dysfunction-associated fatty liver disease (MAFLD) reportedly plays a part in the etiology of colorectal tumors. However, there is no consensus.

Methods

Studies relevant with the impact of MAFLD severity on the risk of colorectal neoplasms published before 24th April 2022 were screened. The pooled odds ratio (OR) with corresponding 95% confidence intervals (95% CI) was obtained using standard and cumulative meta-analyses. Subgroup, meta-regression, and sensitivity analyses were carried out to identify heterogeneity.

Results

Fourteen studies with data from 37,824 MAFLD patients were included. The prevalence of colorectal neoplasms escalated with the progression of MAFLD compared to simple steatosis (OR = 1.93; 95% CI = 1.42–2.62). The magnitude and direction of the effect on these outcomes remained largely constant over time. Even after limiting the meta-analysis to 8 studies with available adjusted OR (aOR), the findings still suggested that MAFLD severity was positively related to colorectal neoplasms (aOR = 3.03; 95% CI = 2.02–4.53). Severe MAFLD was more likely to cause left colon tumors (OR = 3.86, 95% CI = 2.16–6.91) than right colon neoplasms (OR = 1.94, 95% CI = 1.15–3.28).

Conclusion

The severity of MAFLD was independently related to colorectal neoplasms and severe MAFLD was more likely to cause left colon tumors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01659-1.

Nonalcoholic fatty liver disease and health outcomes: An umbrella review of systematic reviews and meta-analyses

Purpose:

A large number of systemic reviews and meta-analyses have explored the relationship between nonalcoholic fatty liver disease (NAFLD) and multiple health outcomes. The aim of this study is to conduct an umbrella review to assess the strength and evidence for the association between NAFLD and health outcomes.

Methods:

We systematically identified the present meta-analyses of observational studies reporting an association between NAFLD and health outcomes. For each meta-analysis, we assessed the quality with AMSTAR2 and graded the epidemiologic evidence.

Results:

Fifty-four articles comprising 111 unique meta-analyses were included in this study. Eighty-five unique outcomes showed significant associations ( P ← 0.05), whereas 26 unique outcomes showed insignificant associations, and we cannot assess the epidemiologic evidence. For 85 significant health outcomes, four outcomes (carotid intima-media thickness (C-IMT), peak A velocity, left ventricle end-diastolic diameter, incident chronic kidney disease (CKD) in adult patients) was graded as high quality of evidence, 23 outcomes were graded as the moderate quality of evidence, and the remaining 58 outcomes were graded as weak quality of evidence. Fourty-seven (87.03%) studies showed critically low methodological quality.

Conclusion:

In this umbrella review, only four statistically significant health outcomes showed high epidemiologic evidence. NAFLD seems to relate to an increased risk of C-IMT, peak A velocity, left ventricle end-diastolic diameter, and incident CKD in adult patients.

Metabolic-associated Fatty Liver Disease (MAFLD): A Multi-systemic Disease Beyond the Liver

Nonalcoholic fatty liver disease (NAFLD) is a multisystemic clinical condition that presents with a wide spectrum of extrahepatic manifestations, such as obesity, type 2 diabetes mellitus, metabolic syndrome, cardiovascular diseases, chronic kidney disease, extrahepatic malignancies, cognitive disorders, and polycystic ovarian syndrome. Among NAFLD patients, the most common mortality etiology is cardiovascular disorders, followed by extrahepatic malignancies, diabetes mellitus, and liver-related complications. Furthermore, the severity of extrahepatic diseases is parallel to the severity of NAFLD. In clinical practice, awareness of the associations of concomitant diseases is of major importance for initiating prompt and timely screening and multidisciplinary management of the disease spectrum. In 2020, a consensus from 22 countries redefined the disease as metabolic (dysfunction)-associated fatty liver disease (MAFLD), which resulted in the redefinition of the corresponding population. Although the patients diagnosed with MAFLD and NAFLD mostly overlap, the MAFLD and NAFLD populations are not identical. In this review, we compared the associations of key extrahepatic diseases between NAFLD and MAFLD.

Factors Affecting Adenoma Risk Level in Patients with Intestinal Polyp and Association Analysis

Objective. To explore the factors affecting the adenoma risk level in patients with intestinal polyp and association. Methods. The clinical data of 3,911 patients with intestinal polyp treated in our hospital from January 2018 to January 2021 were retrospectively analyzed, all patients accepted the histopathological examination, their risk of suffering from adenoma was evaluated according to the results of pathological diagnosis, and relevant hazard factors affecting adenoma risk level in them were analyzed by multifactor logistic regression analysis. Results. The results of multifactor logistic analysis showed that male gender, age ≥60 years, number of polyps >3, diameter ≥2 cm, onset at colon, and physiologically tubulovillous adenoma were the hazard factors causing high-grade adenoma risk in patients with intestinal polyp. Conclusion. There are many risk factors causing high-grade adenoma in patients with intestinal polyp, and therefore, the screening for high-risk population shall be enhanced to reduce the potential of carcinomatous change in such patients.

Nonalcoholic fatty liver disease as a metabolic disease in humans: A literature review

AIMS

To conduct a systematic literature review to identify recent epidemiological, biomarker, genetic and clinical evidence that expands our understanding of nonalcoholic fatty liver disease (NAFLD) as a metabolic disorder.

MATERIALS AND METHODS

We performed a literature search using PubMed to identify trials, observational studies and meta-analyses published in the past 5 years.

RESULTS

A total of 95 publications met prespecified inclusion criteria and reported on the interplay between NAFLD/nonalcoholic steatohepatitis (NASH) and metabolic dysfunction, in terms of disease burden and/or epidemiology (n = 10), pathophysiology, risk factors and associated conditions (n = 29), diagnosis and biomarkers (n = 34), and treatment approaches (n = 22). There is a growing body of evidence on the links between NAFLD/NASH pathogenesis and mechanisms of metabolic dysfunction, through liver lipid accumulation, insulin resistance, inflammation, apoptosis, and fibrogenic remodelling within the liver. The frequent co-occurrence of NAFLD with obesity, metabolic syndrome and type 2 diabetes supports this premise. Therapeutic approaches originally envisaged for type 2 diabetes or obesity (such as glucagon-like peptide-1 receptor agonists, sodium-glucose co-transporter-2 inhibitors, insulin sensitizers and bariatric surgery) have shown promising signs of benefit for patients with NAFLD/NASH.

CONCLUSIONS

Given the complex interplay between NAFLD and metabolic dysfunction, there is an urgent need for multidisciplinary collaboration and established protocols for care of patients with NAFLD that are individualized and ideally support reduction of overall metabolic risk as well as treatment for NASH.

Nonalcoholic Fatty Liver Disease: Focus on New Biomarkers and Lifestyle Interventions

Nonalcoholic fatty liver disease (NAFLD) is considered a hepatic manifestation of metabolic syndrome, characterized from pathological changes in lipid and carbohydrate metabolism. Its main characteristics are excessive lipid accumulation and oxidative stress, which create a lipotoxic environment in hepatocytes leading to liver injury. Recently, many studies have focused on the identification of the genetic and epigenetic modifications that also contribute to NAFLD pathogenesis and their prognostic implications. The present review is aimed to discuss on cellular and metabolic alterations associated with NAFLD, which can be helpful to identify new noninvasive biomarkers. The identification of accumulated lipids in the cell membranes, as well as circulating cytokeratins and exosomes, provides new insights in understanding of NAFLD. This review also suggests that lifestyle modifications remain the main prevention and/or treatment for NAFLD.

Site-specific risk of colorectal neoplasms in patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis

Background

Many studies have shown that NAFLD is indeed closely related to the occurrence of colon tumors. The aim of this study was to further establish an assessment for the risk associated with NAFLD and the site-specificity of colon tumors.

Methods

We searched the PubMed, Embase, Cochrane, and Scopus databases published from January 1, 1981, to December 15, 2019, assessing the risk of colorectal neoplasms in patients with NAFLD. The primary outcome measure was the incidence of site-specific risk of colorectal neoplasms in patients with NAFLD reported as ORs which pooled under a random-effects model and calculated via Mantel-Haenszel weighting. The study is registered with PROSPERO, number CRD42020162118.

Results

11 articles (12,081 participants) were included in this meta-analysis. After heterogeneity removed, the overall risk-value pooled for right colon tumors(OR = 1.60,95% CI 1.27–2.01,I2 = 58%,P = 0.02)was higher than the left(OR = 1.39,95% CI 1.11–1.73,I2 = 59%,P = 0.02).However, this outcome was unclear when considering gender differences (Male&Right:OR = 1.05; Male&Left:OR = 1.26; Female&Right: OR = 1.17; Female&Left:OR = 1.17).The incidence of right colon tumors(Asian&Right:OR = 1.56)was obviously higher in Asians with NAFLD than the left (Asian&Left:OR = 1.23),while the risk relevance was similar and moderately associated with an increased risk of incident double-sided colorectal tumors in Europeans (European&Right:OR = 1.47; European&Left:OR = 1.41). The outcome of pathological morphology includes: the advanced adenoma OR = 1.82;the tubular adenoma OR = 1.24;the serrated adenoma OR = 2.16.

Conclusions

NAFLD is associated with a high risk of colon tumors, especially in regard to tumors of the right colon, which are more prevalent in Asian populations.

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.

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.

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.

Effect of Non-alcoholic Fatty Liver Disease on the Risk of Synchronous Liver Metastasis: Analysis of 451 Consecutive Patients of Newly Diagnosed Colorectal Cancer

Background: The purpose of this study was to investigate the effect of non-alcoholic fatty liver disease (NAFLD) on the risk of synchronous colorectal liver metastasis (synCRLM).

Methods: A retrospective analysis was performed on 451 consecutive patients with newly diagnosed colorectal cancer (CRC) from January 2014 to January 2019. According to the presence of NAFLD, the CRC patients were divided into two groups, NAFLD group (60 cases) and the control group (391 cases). The clinicopathological features and the prevalence of synCRLM between the two groups were compared. Logistic regression analysis was used to analyze the risk factors of synCRLM. Different non-invasive liver fibrosis scoring models were used to evaluate the effect of advanced fibrosis and cirrhosis stage in NAFLD on the prevalence of synCRLM.

Results: The prevalence of synCRLM was significantly higher in patients with NAFLD than that in patients without NAFLD (18.33 vs. 7.42%; χ² = 7.669, P = 0.006). A logistic regression analysis indicated that NAFLD, CEA, CA19-9, and lymph node status were risk factors for synCRLM, and NAFLD showed the highest hazard ratio (3.930 [95% confidence interval: 1.616 ~ 9.560]). In NAFLD patients, both fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS) were significantly lower in those with synCRLM compared to those without synCRLM [FIB-4: 1.246 (0.833 ~ 1.276) vs. 1.436 (1.016 ~ 2.699), Z = −2.130, P = 0.033; NFS: −1.282 (−2.407 ~ −0.262) vs. −0.255 (−1.582 ~ 0.755), Z = −2.302, P = 0.021; Mann-Whitney test].

Conclusion: NAFLD may be associated with increased liver metastasis, and for NAFLD-related advanced liver fibrosis and cirrhosis may be associated with reduced synchronous liver metastasis in CRC patients. However, the correlation between simple steatosis and steatohepatitis remains to be further determined. Certain factors such as NAFLD, lymph node metastasis, elevated levels of preoperative CEA and CA19-9 are suggesting a high risk of synCRLM.

The progress of non-alcoholic fatty liver disease as the risk of liver metastasis in colorectal cancer

Introduction: The liver is the most common metastatic site of colorectal cancer (CRC), and the long-term survival rate of CRC patients who cannot resect liver metastatic lesions radically is extremely low. Early identification of risk factors for liver metastasis from CRC may be an effective strategy to reduce the incidence of liver metastasis. The incidence of non-alcoholic fatty liver disease (NAFLD) is increasing in parallel with an increasing prevalence of obesity and metabolic syndrome (MS), which has become one of the main causes of chronic liver disease worldwide.Areas covered: An overview of the related research progress of the association between NAFLD and colorectal liver metastasis (CRLM).Expert opinion: Certain research proves that there is a close relationship between NAFLD and CRC, and the presence of NAFLD can promote the formation and development of CRC. Although the effect of liver diseases on the incidence of liver metastasis in CRC has been noted in recent years, the results are inconsistent and haven't reached a unified conclusion. Therefore, the association between liver metastasis and NAFLD remains the main focal point in the evolution of CRC.