Gallstones, Body Mass Index, C-Reactive Protein, and Gallbladder Cancer: Mendelian Randomization Analysis of Chilean and European Genotype Data

Comprehensive single-cell analysis deciphered microenvironmental dynamics and immune regulator olfactomedin 4 in pathogenesis of gallbladder cancer

OBJECTIVE

Elucidating complex ecosystems and molecular features of gallbladder cancer (GBC) and benign gallbladder diseases is pivotal to proactive cancer prevention and optimal therapeutic intervention.

DESIGN

We performed single-cell transcriptome analysis on 230 737 cells from 15 GBCs, 4 cholecystitis samples, 3 gallbladder polyps, 5 gallbladder adenomas and 16 adjacent normal tissues. Findings were validated through large-scale histological assays, digital spatial profiler multiplexed immunofluorescence (GeoMx), etc. Further molecular mechanism was demonstrated with in vitro and in vivo studies.

RESULTS

The cell atlas unveiled an altered immune landscape across different pathological states of gallbladder diseases. GBC featured a more suppressive immune microenvironment with distinct T-cell proliferation patterns and macrophage attributions in different GBC subtypes. Notably, mutual exclusivity between stromal and immune cells was identified and remarkable stromal ecosystem (SC) heterogeneity during GBC progression was unveiled. Specifically, SC1 demonstrated active interaction between Fibro-iCAF and Endo-Tip cells, correlating with poor prognosis. Moreover, epithelium genetic variations within adenocarcinoma (AC) indicated an evolutionary similarity between adenoma and AC. Importantly, our study identified elevated olfactomedin 4 (OLFM4) in epithelial cells as a central player in GBC progression. OLFM4 was related to T-cell malfunction and tumour-associated macrophage infiltration, leading to a worse prognosis in GBC. Further investigations revealed that OLFM4 upregulated programmed death-ligand 1 (PD-L1) expression through the MAPK-AP1 axis, facilitating tumour cell immune evasion.

CONCLUSION

These findings offer a valuable resource for understanding the pathogenesis of gallbladder diseases and indicate OLFM4 as a potential biomarker and therapeutic target for GBC.

Racial and ethnic disparities in gallbladder cancer: A two-decade analysis of incidence and mortality rates in the US

BACKGROUND

Gallbladder cancer (GBC) is an aggressive malignancy that is usually diagnosed at a late stage. Prior data showed increasing incidence of GBC in the US. However, little is known about race/ethnic-specific incidence and mortality trends of GBC per stage at diagnosis. Therefore, we aimed to conduct a time-trend analysis of GBC incidence and mortality rates categorized by race/ethnicity and stage-at-diagnosis.

METHODS

Age-adjusted GBC incidence and mortality rates were calculated using SEER*Stat software from the United States Cancer Statistics database (covers ~98% of US population between 2001 and 2020) and NCHS (covers ~100% of the US population between 2000 and 2020) databases, respectively. Race/Ethnic groups were Non-Hispanic-White (NHW), Non-Hispanic-Black (NHB), Hispanic, Non-Hispanic-Asian/Pacific-Islander (NHAPI), and Non-Hispanic-American-Indian/Alaska-Native (NHAIAN). Stage-at-diagnoses were all stages, early, regional, and distant stages. Joinpoint regression was used to generate time-trends [annual percentage change (APC) and average APC (AAPC)] with parametric estimations and a two-sided t-test (p-value cut-off 0.05).

RESULTS

76,873 patients were diagnosed with GBC with decreasing incidence rates in all races/ethnicities except NHB who experienced an increasing trend between 2001 and 2014 (APC = 2.08, p < 0.01) and plateauing afterward (APC = -1.21, p = 0.31); (AAPC = 1.03, p = 0.03). Among early-stage tumors (9927 patients), incidence rates were decreasing only in Hispanic (AAPC = -4.24, p = 0.006) while stable in other races/ethnicities (NHW: AAPC = -2.61, p = 0.39; NHB: AAPC = -1.73, p = 0.36). For regional-stage tumors (29,690 patients), GBC incidence rates were decreasing only in NHW (AAPC = -1.61, p < 0.001) while stable in other races/ethnicities (NHB: AAPC = 0.73, p = 0.34; Hispanic: AAPC = -1.58, p = 0.24; NHAPI: AAPC = -1.22, p = 0.07). For distant-stage tumors (31,735 patients), incidence rates were increasing in NHB (AAPC = 2.72, p < 0.001), decreasing in Hispanic (AAPC = -0.64, p = 0.04), and stable in NHW (AAPC = 0.07, p = 0.84) and NHAPI (AAPC = 0.79, p = 0.13). There were 43,411 deaths attributed to GBC with decreasing mortality rates in all races/ethnicities except NHB who experienced a stable trend (AAPC = 0.25, p = 0.25).

CONCLUSION

Nationwide data over the last two decades show that NHB patients experienced increasing GBC incidence between 2001 and 2014 followed by stabilization of the rates. This increase was driven by late-stage tumors and occurred in the first decade. NHB also experienced non-improving GBC mortality, compared to other race and ethnic groups who had decreasing mortality. This can be due to lack of timely-access to healthcare leading to delayed diagnosis and worse outcomes. Future studies are warranted to investigate contributions to the revealed racial and ethnic disparities, especially in NHB, to improve early detection.

Prognostic factors for resected cases with gallbladder carcinoma: a systematic review and meta-analysis

OBJECTIVE

Current meta-analysis was performed to systematically evaluate the potential prognostic factors for overall survival among resected cases with gallbladder carcinoma.

METHODS

PubMed, EMBASE, and the Cochrane Library were systematically retrieved and hazard ratio (HR) and its 95% confidence interval were directly extracted from the original study or roughly estimated via Tierney's method. Standard Parmar modifications were used to determine pooled HRs.

RESULTS

A total of 36 studies with 11 502 cases were identified. Pooled results of univariate analyses indicated that advanced age (HR=1.02, P =0.00020), concurrent gallstone disease (HR=1.22, P =0.00200), elevated preoperative CA199 level (HR=1.93, P <0.00001), advanced T stage (HR=3.09, P <0.00001), lymph node metastasis (HR=2.78, P <0.00001), peri-neural invasion (HR=2.20, P <0.00001), lymph-vascular invasion (HR=2.37, P <0.00001), vascular invasion (HR=2.28, P <0.00001), poorly differentiated tumor (HR=3.22, P <0.00001), hepatic side tumor (HR=1.85, P <0.00001), proximal tumor (neck/cystic duct) (HR=1.78, P <0.00001), combined bile duct resection (HR=1.45, P <0.00001), and positive surgical margin (HR=2.90, P <0.00001) were well-established prognostic factors. Pathological subtypes ( P =0.53000) and postoperative adjuvant chemotherapy ( P =0.70000) were not prognostic factors. Pooled results of multivariate analyses indicated that age, gallstone disease, preoperative CA199, T stage, lymph node metastasis, peri-neural invasion, lymph-vascular invasion, tumor differentiation status, tumor location (peritoneal side vs hepatic side), surgical margin, combined bile duct resection, and postoperative adjuvant chemotherapy were independent prognostic factors.

CONCLUSION

Various prognostic factors have been identified beyond the 8th AJCC staging system. By incorporating these factors into a prognostic model, a more individualized prognostication and treatment regime would be developed. Upcoming multinational studies are required for the further refine and validation.

Horizontal duodenal papilla is associated with a special spectrum of pancreaticobiliary diseases: a retrospective magnetic resonance cholangiopancreatography-based study

Background

Horizontal duodenal papilla (HDP) is not an uncommon ectopic major papilla. The impact of HDP on the occurrence of pancreaticobiliary diseases remains unclear. Here, we explored the associations in patients who underwent magnetic resonance cholangiopancreatography (MRCP).

Methods

Consecutive patients who underwent MRCP at Xijing Hospital (Xi'an, China) between January 2020 and December 2021 were eligible. Patients were divided into HDP and regular papilla (RP) according to the position of the major papilla. The primary outcome was the proportion of congenital pancreaticobiliary diseases.

Results

A total of 2,194 patients were included, of whom 72 (3.3%) had HDP. Compared with the RP group (n = 2,122), the HDP group had a higher proportion of congenital pancreaticobiliary diseases, especially choledochal cyst (CC) or anomalous pancreaticobiliary junction (APBJ) (6.9% vs 1.4%, P = 0.001). More gallbladder cancer (6.9% vs 1.2%, P < 0.001) and pancreatic cysts (27.8% vs 16.3%, P = 0.01) were also identified in the HDP group. Morphologically, the HDP group had a longer extrahepatic bile duct (8.4 [7.6-9.3] cm vs 7.2 [6.5-8.1] cm, P < 0.001), and larger angles between the common bile duct-duodenum and pancreatic duct-duodenum. Multivariate analysis showed that the presence of HDP was an independent risk factor for gallbladder cancer.

Conclusions

This study confirmed that HDP was not rare in patients underwent MRCP. A higher prevalence of congenital pancreaticobiliary malformations (especially CC or APBJ), gallbladder cancer and pancreatic cysts was observed in patients with HDP, as well as distinctive morphologic features.

Dietary intake, obesity, and physical activity in association with biliary tract cancer risk: Results from meta-analyses of individual-level data from prospective cohort studies of 723,326 adults

Biliary tract cancer (BTC) is a rare and aggressive malignancy with increasing incidence. Most BTC cases are diagnosed with metastatic disease which carries a 5-year survival rate of <5%. Physical activity, diet, and obesity might be associated with BTC risk, but studies have been limited particularly in African descendants. We addressed this knowledge gap by evaluating associations of BTC risk with obesity, physical activity, and dietary intakes in 723,326 adult participants in four cohort studies conducted in China, the United Kingdom, and the United States. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) in each cohort; results were combined using meta-analysis. All cohorts had ≥11 median follow-up years with 839 incident BTC cases combined. BTC risk was positively associated with body mass index (BMI) and waist-to-hip ratio (WHR) whereas physical activity, fruit intake, and fish intake were inversely associated. HR and (95% CI) comparing BMI >35.0 to 18.5-24.9: 1.71 (1.26, 2.31), p-trend <.0001; comparing BMI-adjusted WHR top to bottom quartile: 1.20 (0.94, 1.53), p-trend = .05; comparing ≥15-0 metabolic equivalent task-hours/week 0.76 (0.61, 0.94), p-trend = .009; comparing highest to lowest intake tertile for fruit and fish 0.79 (0.66, 0.95), p-trend = .01; 0.82 (0.68, 0.98), p-trend = .04, respectively. Associations were, in general, similar across ancestry groups. Our study provides strong evidence for important roles of obesity, diet, and physical activity in BTC etiology and stresses the need for lifestyle modification to combat the rising incidence of this fatal malignancy.

Distinct Driver Pathway Enrichments and a High Prevalence of TSC2 Mutations in Right Colon Cancer in Chile: A Preliminary Comparative Analysis

Colorectal cancer (CRC) is the second leading cause of cancer deaths globally. While ethnic differences in driver gene mutations have been documented, the South American population remains understudied at the genomic level, despite facing a rising burden of CRC. We analyzed tumors of 40 Chilean CRC patients (Chp) using next-generation sequencing and compared them to data from mainly Caucasian cohorts (TCGA and MSK-IMPACT). We identified 388 mutations in 96 out of 135 genes, with TP53 (45%), KRAS (30%), PIK3CA (22.5%), ATM (20%), and POLE (20%) being the most frequently mutated. TSC2 mutations were associated with right colon cancer (44.44% in RCRC vs. 6.45% in LCRC, p-value = 0.016), and overall frequency was higher compared to TCGA (p-value = 1.847 × 10-5) and MSK-IMPACT cohorts (p-value = 3.062 × 10-2). Limited sample size restricts definitive conclusions, but our data suggest potential differences in driver mutations for Chilean patients, being that the RTK-RAS oncogenic pathway is less affected and the PI3K pathway is more altered in Chp compared to TCGA (45% vs. 25.56%, respectively). The prevalence of actionable pathways and driver mutations can guide therapeutic choices, but can also impact treatment effectiveness. Thus, these findings warrant further investigation in larger Chilean cohorts to confirm these initial observations. Understanding population-specific driver mutations can guide the development of precision medicine programs for CRC patients.

Genetics of Gallstone Disease and Their Clinical Significance: A Narrative Review

Gallstone (GS) disease is common and arises from a combination of genetic and environmental factors. Although genetic abnormalities specifically leading to cholesterol GSs are rare, there are clinically significant gene variants associated with cholesterol GSs. In contrast, most bilirubin GSs can be attributed to genetic defects. The pathogenesis of cholesterol and bilirubin GSs differs greatly. Cholesterol GSs are notably influenced by genetic variants within the ABC protein superfamily, including ABCG8, ABCG5, ABCB4, and ABCB11, as well as genes from the apolipoprotein family such as ApoB100 and ApoE (especially the E3/E3 and E3/E4 variants), and members of the MUC family. Conversely, bilirubin GSs are associated with genetic variants in highly expressed hepatic genes, notably UGT1A1, ABCC2 (MRP2), ABCC3 (MRP3), CFTR, and MUC, alongside genetic defects linked to hemolytic anemias and conditions impacting erythropoiesis. While genetic cases constitute a small portion of GS disease, recognizing genetic predisposition is essential for proper diagnosis, treatment, and genetic counseling.

Ganoderma lucidum polysaccharide ameliorates cholesterol gallstone formation by modulating cholesterol and bile acid metabolism in an FXR-dependent manner

BACKGROUND

Cholesterol gallstone (CG) disease is a worldwide common disease characterized by cholesterol supersaturation in gallbladder bile. Ganoderma lucidum polysaccharide (GLP) has been shown to possess various beneficial effects against metabolic disorders. However, the role and underlying mechanism of GLP in CG formation are still unknown. This study aimed to determine the role of GLP in ameliorating lithogenic diet (LD)-induced CG formation.

METHODS

Mice were fed either a normal chow diet, a LD, or LD supplemented with GLP. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to detect the expression of genes involved in cholesterol and bile acid (BA) metabolism. The BA concentrations in the ileum were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The microbiota in cecal contents were characterized using 16S ribosomal RNA (16S rRNA) gene sequencing.

RESULTS

GLP effectively alleviated CG formation induced by LD. Specifically, GLP reduced the total cholesterol (TC) levels, increased the total BA levels, and decreased the cholesterol saturation index (CSI) in gallbladder bile. The protective effect of GLP was attributed to the inhibition of farnesoid X receptor (FXR) signaling, increased hepatic BA synthesis and decreased hepatic cholesterol synthesis and secretion. GLP also altered the BA composition in the ileum, reducing FXR-agonistic BAs and increasing FXR-antagonistic BAs, which may contribute to the inhibition of intestinal FXR signaling. Additionally, GLP improved dysbiosis of the intestinal flora and reduced the serum levels of hydrogen sulfide (H2S), a bacterial metabolite that can induce hepatic FXR, thereby inhibiting hepatic FXR signaling. Moreover, the protective effect of GLP against CG formation could be reversed by both the global and gut-restricted FXR agonists.

CONCLUSIONS

Taken together, GLP ameliorates CG formation by regulating cholesterol and BA metabolism in an FXR-dependent manner. Our study demonstrates that GLP may be a potential strategy for the prevention against CG disease.

A Positive Causal Effect of Shrimp Allergy on Major Depressive Disorder Mediated by Allergy- and Immune-Related Pathways in the East Asian Population

BACKGROUND

Observational studies have implied a potential correlation between allergic diseases and major depressive disorder (MDD). However, the relationship is still inconclusive as it is likely to be interfered with by substantial confounding factors and potential reverse causality. The present study aimed to investigate causal correlation of the two diseases by a Mendelian randomization (MR) study and further elucidate the underlying molecular mechanisms.

METHODS

With the biggest summary datasets of a genome-wide association study (GWAS) in the East Asian population, we conducted a two-sample, bidirectional MR study to assess the causal correlation between shrimp allergy (SA) and MDD. Subsequently, we identified the pleiotropic genes' susceptibility to the two diseases at whole-genome and tissue-specific levels, respectively. Enriched GO sets and KEGG pathways were also discovered to elucidate the potential underlying mechanisms.

RESULTS

With the most suitable MR method, SA was identified as a causal risk factor for MDD based on three different groups of independent genetic instruments, respectively (p < 2.81 × 10-2). In contrast, we did not observe a significant causal effect of MDD on SA. The GWAS-pairwise program successfully identified seven pleiotropic genetic variants (PPA3 > 0.8), indicating that the two diseases indeed have a shared genetic basis. At a whole-genome level, the MAGMA program identified 44 pleiotropic genes, which were enriched in allergy-related pathways, such as antigen processing and presentation pathway (p = 1.46 × 10-2). In brain-specific tissue, the S-MultiXcan program found 17 pleiotropic genes that were significantly enriched in immune-related pathways and GO sets, including asthma-related pathway, T-cell activation-related, and major histocompatibility complex protein-related GO sets. Regarding whole-blood tissue, the program identified six pleiotropic genes that are significantly enriched in tolerance induction-related GO sets.

CONCLUSIONS

The present study for the first time indicated a significant causal effect of SA on the occurrence of MDD, but the reverse was not true. Enrichment analyses of pleiotropic genes at whole-genome and tissue-specific levels implied the involvement of allergy and immune-related pathways in the shared genetic mechanism of the two diseases. Elucidating the causal effect and the acting direction may be beneficial in reducing the incidence rate of MDD for the massive group of SA patients in the East Asian region.

Causal association of serum biomarkers with oral cavity and oropharyngeal cancer: a mendelian randomization study

BACKGROUND

Observational epidemiological studies revealed that multiple serum biomarkers can be associated with the risk of oral and oropharyngeal cancer (OC/OPC). However, the causal relationship between them remains largely unknown. This study aimed to investigate the causal relationship between potential serum biomarkers and (OC/OPC).

METHODS

A two-sample Mendelian randomization (MR) approach was performed to assess the causal association of 10 serum biomarkers with the risk of OC / OPC. Summary data on OC/OPC were obtained from a GWAS meta-analysis that included 2497 cases and 2928 controls. The TwoSampleMR package in R was used to perform MR analyzes. Inverse-variance weighted (IVW), Weighted median and MR-Egger methods were used to assess causal effects.

RESULTS

Suggestive associations with increased risk of C-reactive protein (CRP) (OR 1.52, 95% CI 1.14 to 2.02), using the IVW method. MR-Egger regression suggested that directional pleiotropy was unlikely to bias the result (P = 0.19). The findings were robust to sensitivity analyzes. The risk of OC/OPC was not associated with serum 25-hydroxyvitamin D, HDL cholesterol, LDL cholesterol, total cholesterol, triglycerides, adiponectin, leptin, HbA1C and Insulin-like growth factor 1 (IGF 1).

CONCLUSIONS

This study supports that CRP was causally associated with an increased risk of oral and oropharyngeal cancer.

Insight into the mechanism of gallstone disease by proteomic and metaproteomic characterization of human bile

Introduction

Cholesterol gallstone disease is a prevalent condition that has a significant economic impact. However, the role of the bile microbiome in its development and the host's responses to it remain poorly understood.

Methods

In this study, we conducted a comprehensive analysis of microbial and human bile proteins in 40 individuals with either gallstone disease or gallbladder polyps. We employed a combined proteomic and metaproteomic approach, as well as meta-taxonomic analysis, functional pathway enrichment, and Western blot analyses.

Results

Our metaproteomic analysis, utilizing the lowest common ancestor algorithm, identified 158 microbial taxa in the bile samples. We discovered microbial taxa that may contribute to gallstone formation, including β-glucuronidase-producing bacteria such as Streptococcus, Staphylococcus, and Clostridium, as well as those involved in biofilm formation like Helicobacter, Cyanobacteria, Pseudomonas, Escherichia coli, and Clostridium. Furthermore, we identified 2,749 human proteins and 87 microbial proteins with a protein false discovery rate (FDR) of 1% and at least 2 distinct peptides. Among these proteins, we found microbial proteins crucial to biofilm formation, such as QDR3, ompA, ndk, pstS, nanA, pfIB, and dnaK. Notably, QDR3 showed a gradual upregulation from chronic to acute cholesterol gallstone disease when compared to polyp samples. Additionally, we discovered other microbial proteins that enhance bacterial virulence and gallstone formation by counteracting host oxidative stress, including sodB, katG, rbr, htrA, and ahpC. We also identified microbial proteins like lepA, rtxA, pckA, tuf, and tpiA that are linked to bacterial virulence and potential gallstone formation, with lepA being upregulated in gallstone bile compared to polyp bile. Furthermore, our analysis of the host proteome in gallstone bile revealed enhanced inflammatory molecular profiles, including innate immune molecules against microbial infections. Gallstone bile exhibited overrepresented pathways related to blood coagulation, folate metabolism, and the IL-17 pathway. However, we observed suppressed metabolic activities, particularly catabolic metabolism and transport activities, in gallstone bile compared to polyp bile. Notably, acute cholelithiasis bile demonstrated significantly impaired metabolic activities compared to chronic cholelithiasis bile.

Conclusion

Our study provides a comprehensive metaproteomic analysis of bile samples related to gallstone disease, offering new insights into the microbiome-host interaction and gallstone formation mechanism.

Amerindian ancestry proportion as a risk factor for inflammatory bowel diseases: results from a Latin American Andean cohort

Background and aims

Latin American populations remain underrepresented in genetic studies of inflammatory bowel diseases (IBDs). Most genetic association studies of IBD rely on Caucasian, African, and Asian individuals. These associations have yet to be evaluated in detail in the Andean region of South America. We explored the contribution of IBD-reported genetic risk variants to a Chilean cohort and the ancestry contribution to IBD in this cohort.

Methods

A total of 192 Chilean IBD patients were genotyped using Illumina's Global Screening Array. Genotype data were combined with similar information from 3,147 Chilean controls. The proportions of Aymara, African, European, and Mapuche ancestries were estimated using the software ADMIXTURE. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for gender, age, and ancestry proportions. We also explored associations with previously reported IBD-risk variants independently and in conjunction with genetic ancestry.

Results

The first and third quartiles of the proportion of Mapuche ancestry in IBD patients were 24.7 and 34.2%, respectively, and the corresponding OR was 2.30 (95%CI 1.52-3.48) for the lowest vs. the highest group. Only one variant (rs7210086) of the 180 reported IBD-risk SNPs was associated with IBD risk in the Chilean cohort (adjusted P = 0.01). This variant is related to myeloid cells.

Conclusion

The type and proportion of Native American ancestry in Chileans seem to be associated with IBD risk. Variants associated with IBD risk in this Andean region were related to myeloid cells and the innate immune response.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Correlation of serum biochemical characteristics and ABCG8 genetic variant (rs 11887534) with gall stone compositions and risk of gallstone disease in Egyptian patients

BACKGROUND

The overexpression of the cholesterol transporter: ATP-binding cassette transporter (ABCG8) due to the effect of ABCG8 genetic variant (rs11887534) leads to the precipitation of cholesterol crystals and gallstone disease (GSD).

OBJECTIVE

To evaluate the chemical composition of gallstones and the role of ABCG8 (rs11887534) in the susceptibility to GSD.

METHODS

We enrolled 77 patients with GSD treated with standard laparoscopic or open cholecystectomy and 75 age and sex-matched healthy controls. Chemical analysis of the extracted gallstones was performed. Analysis of the rs11887534 was performed by real-time PCR TaqMan technique for both cases and controls.

RESULTS

Pure cholesterol stones were the main type of stones in GSD patients. The CC genotype carriers of rs11887534 were more prone to gallstone formation than other genotypes. The CC genotype carriers were 100 folds at increased risk to develop pure cholesterol stones.

CONCLUSION

The most prevalent type of gallbladder stones is pure cholesterol stone. ABCG8 (rs11887534) could be associated with increased risk for cholesterol gallstones formation, this risk was more pronounced in female patients.

Gallbladder Cancer Risk and Indigenous South American Mapuche Ancestry: Instrumental Variable Analysis Using Ancestry-Informative Markers

A strong association between the proportion of indigenous South American Mapuche ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest indigenous people in Chile. We set out to assess the confounding-free effect of the individual proportion of Mapuche ancestry on GBC risk and to investigate the mediating effects of gallstone disease and body mass index (BMI) on this association. Genetic markers of Mapuche ancestry were selected based on the informativeness for assignment measure, and then used as instrumental variables in two-sample Mendelian randomization analyses and complementary sensitivity analyses. Results suggested a putatively causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% per 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.7 × 10-5) and also on gallstone disease (3.6% IVW risk increase, 95% CI 3.1% to 4.0%), pointing to a mediating effect of gallstones on the association between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative effect on BMI (IVW estimate -0.006 kg/m2, 95% CI -0.009 to -0.003). The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between the individual proportion of Mapuche ancestry and GBC risk previously noted in observational studies appears to be free of confounding, primary and secondary prevention strategies that consider genetic ancestry could be particularly efficient.

Prognostic value of preoperative hematological markers in patients with glioblastoma multiforme and construction of random survival forest model

OBJECTIVE

In recent years, an increasing number of studies have revealed that patients' preoperative inflammatory response, coagulation function, and nutritional status are all linked to the occurrence, development, angiogenesis, and metastasis of various malignant tumors. The goal of this study is to determine the relationship between preoperative peripheral blood neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR), systemic immune-inflammatory index (SII), platelet to lymphocyte ratio (PLR), and platelet to fibrinogen ratio (FPR). Prognostic nutritional index (PNI) and the prognosis of glioblastoma multiforme (GBM) patients, as well as establish a forest prediction model that includes preoperative hematological markers to predict the individual GBM patient's 3-year survival status after treatment.

METHODS

The clinical and hematological data of 281 GBM patients were analyzed retrospectively; overall survival (OS) was the primary endpoint. X-Tile software was used to determine the best cut-off values for NLR, SII, and PLR, and the survival analysis was carried out by the Kaplan-Meier method as well as univariate and multivariate COX regression. Afterward, we created a random forest model that predicts the individual GBM patient's 3-year survival status after treatment, and the area under the curve (AUC) is used to validate the model's effectiveness.

RESULTS

The best cut-off values for NLR, SII, and PLR in GBM patients' preoperative peripheral blood were 2.12, 537.50, and 93.5 respectively. The Kaplan-Meier method revealed that preoperative GBM patients with high SII, high NLR, and high PLR had shorter overall survival, and the difference was statistically significant. In addition to clinical and pathological factors. Univariate Cox showed NLR (HR = 1.456, 95% CI: 1.286 ~ 1.649, P < 0.001) MLR (HR = 1.272, 95% CI: 1.120 ~ 1.649, P < 0.001), FPR (HR = 1.183,95% CI: 1.049 ~ 1.333, P < 0.001), SII (HR = 0.218,95% CI: 1.645 ~ 2.127, P < 0.001) is related to the prognosis and overall survival of GBM. Multivariate Cox proportional hazard regression showed that SII (HR = 1.641, 95% CI: 1.430 ~ 1.884, P < 0.001) is also related to the overall survival of patients with GBM. In the random forest prognostic model with preoperative hematologic markers, the AUC in the test set and the validation set was 0.907 and 0.900, respectively.

CONCLUSION

High levels of NLR, MLR, PLR, FPR, and SII before surgery are prognostic risk factors for GBM patients. A high preoperative SII level is an independent risk factor for GBM prognosis. The random forest model that includes preoperative hematological markers has the potential to predict the individual GBM patient's 3-year survival status after treatment,and assist the clinicians for making a good clinical decision.

Effect of hepatic NPC1L1 on cholesterol gallstone disease and its mechanism

Cholesterol gallstone disease (CGD) is associated with bile cholesterol supersaturation. The Niemann-Pick C1-like 1 (NPC1L1), the inhibitory target of ezetimibe (EZE), is a critical sterol transporter of cholesterol absorption. Intestinal NPC1L1 facilitates the absorption of cholesterol, whereas hepatic NPC1L1 promotes cholesterol uptake by hepatocytes and reduces bile cholesterol supersaturation. The potential of hepatic NPC1L1 to prevent CGD has yet to be established due to its absence in the mice model. In this study, we generated mice expressing hepatic NPC1L1 using adeno-associated virus (AAV) gene delivery. The biliary cholesterol saturations and gallstone formations were explored under chow diet and lithogenic diet (LD) with or without EZE treatment. The long-term (8-week) LD-fed AAV-mNPC1L1 mice exhibited no significant differences in biliary cholesterol saturation and gallstone formation compared to WT mice. EZE effectively prevented CGD in both WT and AAV-mNPC1L1 mice. Mechanistically, prolonged LD feeding induced the degradation of hepatic NPC1L1, whereas short-term (2-week) LD feeding preserved the expression of hepatic NPC1L1. In conclusion, our findings suggest that hepatic NPC1L1 is unable to prevent CGD, whereas EZE functions as an efficient bile cholesterol desaturator during CGD development.

Body mass index, C-reactive protein, and pancreatic cancer: A Mendelian randomization analysis to investigate causal pathways

Aim

To explore whether C-reactive protein (CRP) mediates the risk of body mass index (BMI) in pancreatic cancer (PC) and calculate the mediate proportion of CRP in this possible mechanism.

Methods

Based on two-sample Mendelian randomization (TSMR), a two-step Mendelian randomization (TM) model was conducted to determine whether CRP was a mediator of the causal relationship between BMI and PC. The multivariable Mendelian randomization (MVMR) study was designed for mediating analysis and to calculate the mediating proportion mediated by CRP.

Results

BMI has a positive causal relationship with PC (n = 393 SNPs, OR = 1.484, 95% CI: 1.021-2.157, p< 0.05). BMI has a positive causal relationship with CRP (n = 179 SNPs, OR = 1.393, 95% CI: 1.320-1.469, p< 0.05). CRP has a positive causal relationship with PC (n = 54 SNPs, OR = 1.348, 95% CI: 1.004-1.809, p< 0.05). After adjusting CRP, BMI has no causal relationship with PC (n = 334 SNPs, OR = 1.341, 95% CI: 0.884-2.037, p< 0.05). After adjusting BMI, there was still a positive causal relationship between CRP and PC (n = 334 SNPs, OR = 1.441, 95% CI: 1.064-1.950, p< 0.05). The mediating effect of CRP was 29%.

Conclusions

In clinical practice, while actively advocating for weight loss among obese patients, we should focus on chronic inflammation levels in obese patients as well. In addition, anti-inflammatory dietary patterns and appropriate physical activity are important in preventing PC.

Gallbladder cancer

Gallbladder cancer (GBC) is the most common cancer of the biliary tract, characterized by a very poor prognosis when diagnosed at advanced stages owing to its aggressive behaviour and limited therapeutic options. Early detection at a curable stage remains challenging because patients rarely exhibit symptoms; indeed, most GBCs are discovered incidentally following cholecystectomy for symptomatic gallbladder stones. Long-standing chronic inflammation is an important driver of GBC, regardless of the lithiasic or non-lithiasic origin. Advances in omics technologies have provided a deeper understanding of GBC pathogenesis, uncovering mechanisms associated with inflammation-driven tumour initiation and progression. Surgical resection is the only treatment with curative intent for GBC but very few cases are suitable for resection and most adjuvant therapy has a very low response rate. Several unmet clinical needs require to be addressed to improve GBC management, including discovery and validation of reliable biomarkers for screening, therapy selection and prognosis. Standardization of preneoplastic and neoplastic lesion nomenclature, as well as surgical specimen processing and sampling, now provides reproducible and comparable research data that provide a basis for identifying and implementing early detection strategies and improving drug discovery. Advances in the understanding of next-generation sequencing, multidisciplinary care for GBC, neoadjuvant and adjuvant strategies, and novel systemic therapies including chemotherapy and immunotherapies are gradually changing the treatment paradigm and prognosis of this recalcitrant cancer.

Research progress on the immune microenvironment of the gallbladder in patients with cholesterol gallstones

Cholesterol gallstones are very common in hepatobiliary surgery and have been studied to a certain extent by doctors worldwide for decades. However, the mechanism of cholesterol gallstone formation is not fully understood, so there is currently no completely effective drug for the treatment and prevention of cholesterol gallstones. The formation and development of cholesterol gallstones are caused by a variety of genetic and environmental factors, among which genetic susceptibility, intestinal microflora disorders, impaired gallbladder motility, and immune disorders are important in the pathogenesis of cholesterol gallstones. This review focuses on recent advances in these mechanisms. We also discuss some new targets that may be effective in the treatment and prevention of cholesterol gallstones, which may be hot areas in the future.

C-reactive protein and cancer risk: a pan-cancer study of prospective cohort and Mendelian randomization analysis

BACKGROUND

Although observational studies have reported associations between serum C-reactive protein (CRP) concentration and risks of lung, breast, and colorectal cancer, inconsistent or absent evidences were showed for other cancers. We conducted a pan-cancer analysis to comprehensively assess the role of CRP, including linearity and non-linearity associations.

METHODS

We analyzed 420,964 cancer-free participants from UK Biobank cohort. Multivariable-adjusted Cox proportional hazards model was conducted to evaluate the observed correlation of CRP with overall cancer and 21 site-specific cancer risks. Furthermore, we performed linear and non-linear Mendelian randomization analyses to explore the potential causal relation between them.

RESULTS

During a median follow-up period of 7.1 years (interquartile range: 6.3, 7.7), 34,979 incident cancer cases were observed. Observational analyses showed higher CRP concentration was associated with increased risk of overall cancer (hazard ratio (HR) = 1.02, 95% CI: 1.01, 1.02 per 1mg/L increase, P < 0.001). There was a non-linear association between CRP and overall cancer risk with inflection point at 3mg/L (false-discovery rate adjust (FDR-adjusted) P_overall < 0.001 and FDR-adjusted P_non-linear < 0.001). For site-specific cancer, we observed positive linear associations for cancers of esophagus and stomach (FDR-adjusted P_overall < 0.050 and FDR-adjusted P_non-linear > 0.050). In addition, we also observed three different patterns of non-linear associations, including "fast-to-low increase" (head and neck, colorectal, liver, lung, kidney cancer, and non-Hodgkin lymphoma), "increase-to-decrease" (breast cancer), and "decrease-to-platform" (chronic lymphocytic leukemia). Furthermore, the inflection points of non-linear association patterns were consistently at around 3mg/L. By contrast, there was no evidence for linear or non-linear associations between genetically predicted CRP and risks of overall cancer or site-specific cancers.

CONCLUSIONS

Our results indicated that CRP was a potential biomarker to assess risks of overall cancer and 12 site-specific cancers, while no association were observed for genetically-predicted CRP and cancer risks.

Development of an Application for Electronic Retrieval of Patient and Sample Information in Latin American Regions with a High Incidence of Gallbladder Cancer

The European-Latin American Consortium towards Eradication of Preventable Gallbladder Cancer, EULAT Eradicate GBC, is collecting high-quality data and samples in four Latin American countries with high gallbladder cancer incidence (Argentina, Bolivia, Chile, and Peru) to build a unique biorepository integrated into a tailored IT platform, to identify, validate, and functionally characterize new risk biomarkers, and to develop prediction models that integrate epidemiological and genetic-molecular risk factors. We decided to develop an application for electronic data collection to facilitate the retrieval of sociodemographic, clinical, lifestyle, dietary, and sample-related information from 15,000 Latin American study participants. The application EULAT eCollect will facilitate the work of study nurses, reduce time spent by participants, limit the use of paper and ink, minimize costs and errors associated with filling out written forms and subsequent digitisation, and support the monitoring of local recruitment rates and data quality. We describe in this article the design and implementation of the EULAT eCollect application, which started with the specification of functional and non-functional requirements, and ended with the implementation and validation of four separate application modules: Socio-Demographic Interview, Sample Information, Case Report Form, and Food-Frequency Questionnaire. We present both general and technical results, and our experience with the free and open-source software, Open Data Kit (ODK), which may be of interest for future related research projects, especially those on personalised cancer prevention carried out in low- and middle-income regions.

Examination on the risk factors of cholangiocarcinoma: A Mendelian randomization study

Background: Several risk factors have been identified for CCA, however, whether such associations were causal remains unknown.

Methods: Mendelian randomization (MR) has been applied to examine the causal relationship between 26 putative risk factors and CCA. The genetic variants for each risk factor were extracted from their corresponding genome-wide association study (GWAS) if they reached the genome-wide significance (p-value < 5 × 10⁻⁸). The genetic associations with CCA were obtained from the publicly available GWAS with the largest sample size. Mainly, inverse-variance weighted (IVW) has been adopted to estimate the causal effect on CCA. Both multivariable and mediation MR analyses were carried out to detect independent factors.

Results: Three putative risk factors can causally elevate the risk of CCA after FDR correction, including liver fat content (LFC), non-alcoholic fatty liver disease (NAFLD), and cholelithiasis. The odds of CCA would increase per 1-SD increase in the liver fat content (LFC) (OR = 2.12 [1.66, 2.71]) and logOR of NAFLD. The genetic liability to cholelithiasis would increase the risk of CCA as well (OR = 2.17 [1.47, 3.20]). They were still significant in other methods. The multivariable MR analysis indicated that genetically-elevated LFC should increase the risk of CCA independently of cholelithiasis (OR = 1.88 [1.39, 2.55]). In the mediation MR analysis, the indirect effect was not significant when treating cholelithiasis as the mediator (indirect OR = 0.95 [0.85, 1.07]).

Conclusion: This MR study identified that gallstone and liver fat accumulation are two independent risk factors of CCA, suggesting two modifiable ways of preventing CCA.

A Novel Systemic Inflammation Prognostic Score to Stratify Survival in Elderly Patients With Cancer

Background

Elderly patients with cancer face the challenge of systemic inflammation, which can lead to a poor prognosis. Existing inflammatory indices cannot fully reflect the immune-inflammatory status of patients. This study aimed to develop a new scoring system to predict the survival of elderly patients with cancer using inflammatory indices, namely, the systemic inflammation prognostic score (SIPS).

Materials and Methods

This prospective multicenter study included a total of 1,767 patients with cancer, with a mean age of 70.97 ± 5.49 years, of whom 1,170 (66.2%) were men. We performed the least absolute shrinkage and selection operator (LASSO) regression to screen inflammatory indicators to include in constructing SIPS. Prognostic analysis of SIPS was performed using univariate and multivariate survival analyzes. The prognostic value of SIPS and its components were compared using the prognostic receiver operating characteristic curve and concordance index. The population was divided into the training cohort and the validation cohort in a 7:3 ratio and a SIPS prognostic analysis was performed.

Results

The LASSO regression selected C-reactive protein (CRP) (≤ 9.81, “0”; &gt; 9.81, “1”), geriatric nutritional risk index (GNRI) (≤ 93.85, “1”; 93.85, “0”), advanced lung cancer inflammation index (ALI) (≤ 23.49, “1”; &gt; 23.49, “0”), and lymphocyte to C-reactive protein ratio (LCR) (≤ 2523.81, “1”; &gt; 2523.81, “0”) to develop SIPS. Patients were divided into the three groups based on the total SIPS: low-risk (0), moderate-risk (1–2), and high-risk (3–4). On the multivariate survival analysis, patients in the moderate-risk [P &lt; 0.001, hazard ratio (HR) = 1.79, 95% CI: 1.47–2.17] and high-risk groups (P &lt; 0.001, HR = 2.40, 95% CI: 1.98–2.92) showed a worse prognosis than those in the low-risk group. The total cohort, training cohort, and validation cohort all showed that SIPS had better survival prediction than CRP, GNRI, ALI, and LCR. The HRs were 2.81 times higher in patients in the high-risk group with malnutrition than in patients in the low-risk group without malnutrition.

Conclusion

SIPS was an independent prognostic indicator in elderly patients with cancer. Malnutrition in the high-risk group increased the mortality risk.

A Novel Clinically Prognostic Stratification Based on Prognostic Nutritional Index Status and Histological Grade in Patients With Gallbladder Cancer After Radical Surgery

Purpose

Gallbladder carcinoma (GBC) is the most common malignancy of the biliary tract, with a 5-year survival rate of 5%. The prognostic models to predict the prognosis of patients with GBC remain controversial. Therefore, to construct a prognosis prediction of GBC, a retrospective cohort study was carried out to investigate the prognostic nutritional index and histological grade in the long-term outcome of patients with GBC after radical surgery (RS).

Methods

A retrospective study of a total of 198 patients with GBC who underwent surgical treatment were enrolled. The hematological indicators, imageological data, and perioperative clinical data were acquired for statistical analysis and poor prognosis model construction.

Results

Prognostic nutrition index (PNI) < 45.88, maximum tumor diameter (MTD) > 2.24 cm, and jaundice (JD) were all associated with a poor prognosis in multivariate logistic regression analysis. The prognosis prediction model was based on the three risk factors, which indicated a superior predictive ability in the primary cohort [area under the curve (AUC) = 0.951] and validation cohort (AUC = 0.888). In multivariate Cox regression analysis, poorly differentiation (PD) was associated with poor 3-year survival. In addition, Kaplan-Meier (KM) survival analysis suggested that GBC patients with high-risk scores and PD had a better prognosis after RS (p < 0.05), but there was no significant difference in prognosis for patients with non-poorly differentiation (NPD) or low-risk scores after RS (p > 0.05).

Conclusion

Our prediction model for GBC patients with prognosis evaluation is accurate and effective. For patients with PD and high-risk scores, RS is highly recommended; a simple cholecystectomy can also be considered for acceptance for patients with NPD or low-risk score. The significant findings provide a new therapeutic strategy for the clinical treatment of GBC.

Long-term exposure to genistein inhibits the proliferation of gallbladder cancer by downregulating the MCM complex

Soy isoflavones are natural tyrosine kinase inhibitors closely associated with decreased morbidity and mortality of various tumors. The activation of tyrosine kinases such as ERBB2 is the mechanism by which cholecystitis transforms into gallbladder cancer (GBC), therefore, it is important to investigate the relationship between long-term exposure to soy isoflavones and the occurrence and progression of GBC. This case-control study (n = 85 pairs) found that the high level of plasma soy isoflavone-genistein (GEN) was associated with a lower risk of gallbladder cancer (≥326.00 ng/mL compared to ≤19.30 ng/mL, crude odds ratio 0.15, 95% CI 0.04-0.59; P for trend = 0.016), and that the level of GEN exposure negatively correlated with Ki67 expression in GBC tissue (n = 85). Consistent with these results, the proliferation of GBC cells was inhibited in the long-term exposure models of GEN in vitro and in vivo. The long-term exposure to GEN reduced the tyrosine kinase activity of ERBB2 and impaired the function of the PTK6-AKT-GSK3β axis, leading to downregulation of the MCM complex in GBC cells. In summary, long-term exposure to GEN associated with soy products intake might play a certain role in preventing GBC and even inhibiting the proliferation of GBC cells.

Factors Influencing Gallstone Formation: A Review of the Literature

Gallstone disease is a common pathology of the digestive system with nearly a 10–20% incidence rate among adults. The mainstay of treatment is cholecystectomy, which is commonly associated with physical pain and may also seriously affect a patient’s quality of life. Clinical research suggests that cholelithiasis is closely related to the age, gender, body mass index, and other basic physical characteristics of patients. Clinical research further suggests that the occurrence of cholelithiasis is related to obesity, diabetes, non-alcoholic fatty liver, and other diseases. For this reason, we reviewed the following: genetic factors; excessive liver cholesterol secretion (causing cholesterol supersaturation in gallbladder bile); accelerated growth of cholesterol crystals and solid cholesterol crystals; gallbladder motility impairment; and cardiovascular factors. Herein, we summarize and analyze the causes and mechanisms of cholelithiasis, discuss its correlation with the pathogenesis of related diseases, and discuss possible mechanisms.

Blood lipid metabolism and the risk of gallstone disease: a multi-center study and meta-analysis

Background

Gallstone disease (GSD) is a common and costly biliary disorder. Multiple studies have investigated the associations between blood lipid metabolism and GSD risk; however, the results are inconsistent. This research aimed to comprehensively evaluate the relationships among serum total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides and GSD risk.

Methods

Firstly, a multi-center cross-sectional study was carried out. Subjects who participated in the health examination in three hospitals between January 2015 and May 2020 were recruited. Multivariable logistic regression was used to investigate blood lipid metabolism associated with GSD risk. Then, a meta-analysis was performed to verify the associations further. Medline and Embase databases were systematically searched before June 10, 2021. The DerSimonian and Laird random-effect model was utilized when the heterogeneity was high; otherwise, fixed-effect model was adopted.

Results

There were 548,934 eligible participants included in the multi-center study, and 45,392 of them were diagnosed with GSD. The results demonstrated that total cholesterol and HDL cholesterol were negatively associated with GSD risk in both high vs. low model and per mmol/L increase model, while triglyceride was positively associated with GSD risk in the per unit increase model. In the meta-analysis, 104 studies with approximately 3 million participants were finally included. The results verified that HDL cholesterol [odds ratio (OR) = 0.636, P = 5.97 × 10^− 16 in high vs low model; OR = 0.974, P = 6.07 × 10^− 05 in per unit model] and triglyceride (OR = 1.192, P = 3.47 × 10^− 05 in high vs. low model; OR = 1.011, P = 5.12 × 10^− 05 in per unit model) were related to GSD risk in the two models.

Conclusions

The findings indicated that low HDL cholesterol levels and high triglyceride levels were risk factors for GSD. This study provides a basis for identifying the population at high risk for GSD and implementing tertiary prevention strategies for GSD, thus contributing to GSD prevention as well as disease burden relief.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01635-9.

Environmental and Lifestyle Risk Factors in the Carcinogenesis of Gallbladder Cancer

Gallbladder cancer (GBC) is an aggressive neoplasm that in an early stage is generally asymptomatic and, in most cases, is diagnosed in advanced stages with a very low life expectancy because there is no curative treatment. Therefore, understanding the early carcinogenic mechanisms of this pathology is crucial to proposing preventive strategies for this cancer. The main risk factor is the presence of gallstones, which are associated with some environmental factors such as a sedentary lifestyle and a high-fat diet. Other risk factors such as autoimmune disorders and bacterial, parasitic and fungal infections have also been described. All these factors can generate a long-term inflammatory state characterized by the persistent activation of the immune system, the frequent release of pro-inflammatory cytokines, and the constant production of reactive oxygen species that result in a chronic damage/repair cycle, subsequently inducing the loss of the normal architecture of the gallbladder mucosa that leads to the development of GBC. This review addresses how the different risk factors could promote a chronic inflammatory state essential to the development of gallbladder carcinogenesis, which will make it possible to define some strategies such as anti-inflammatory drugs or public health proposals in the prevention of GBC.

Systematic review of Mendelian randomization studies on risk of cancer

BACKGROUND

We aimed to map and describe the current state of Mendelian randomization (MR) literature on cancer risk and to identify associations supported by robust evidence.

METHODS

We searched PubMed and Scopus up to 06/10/2020 for MR studies investigating the association of any genetically predicted risk factor with cancer risk. We categorized the reported associations based on a priori designed levels of evidence supporting a causal association into four categories, namely robust, probable, suggestive, and insufficient, based on the significance and concordance of the main MR analysis results and at least one of the MR-Egger, weighed median, MRPRESSO, and multivariable MR analyses. Associations not presenting any of the aforementioned sensitivity analyses were not graded.

RESULTS

We included 190 publications reporting on 4667 MR analyses. Most analyses (3200; 68.6%) were not accompanied by any of the assessed sensitivity analyses. Of the 1467 evaluable analyses, 87 (5.9%) were supported by robust, 275 (18.7%) by probable, and 89 (6.1%) by suggestive evidence. The most prominent robust associations were observed for anthropometric indices with risk of breast, kidney, and endometrial cancers; circulating telomere length with risk of kidney, lung, osteosarcoma, skin, thyroid, and hematological cancers; sex steroid hormones and risk of breast and endometrial cancer; and lipids with risk of breast, endometrial, and ovarian cancer.

CONCLUSIONS

Despite the large amount of research on genetically predicted risk factors for cancer risk, limited associations are supported by robust evidence for causality. Most associations did not present a MR sensitivity analysis and were thus non-evaluable. Future research should focus on more thorough assessment of sensitivity MR analyses and on more transparent reporting.

The Prognostic Value of the Prognostic Nutritional Index in Operable High-Grade Glioma Patients and the Establishment of a Nomogram

Background

Studies confirmed the predictive value of the prognostic nutrition index (PNI) in many malignant tumors. However, it did not reach a consensus in glioma. Therefore, this study investigated the prognostic value of preoperative PNI in operable high-grade glioma and established a nomogram.

Methods

Clinical data of high-grade glioma patients were retrospectively analyzed. The primary endpoint was overall survival (OS). Survival analysis was conducted by the Kaplan–Meier method, log-rank test, and Cox regression analysis. A nomogram was established. The prediction effect of the nomogram covering PNI was verified by area under the curve (AUC).

Results

A total of 91 operable high-grade glioma patients were included. Kaplan–Meier analysis showed that among grade IV gliomas (n = 55), patients with higher PNI (>44) showed a trend of OS benefit (p = 0.138). In grade III glioma (n = 36), patients with higher PNI (>47) had longer OS (p = 0.023). However, the intersecting Kaplan–Meier curve suggested that there may be some confounding factors. Cox regression analysis showed that higher PNI was an independent prognostic factor for grade IV glioma (HR = 0.388, p = 0.040). In grade III glioma, there was no statistically relationship between PNI levels and prognosis. When evaluating the prognostic ability of PNI alone by ROC, the AUC in grade III and IV gliomas was low, indicating that PNI alone had poor predictive power for OS. Interestingly, we found that the nomogram including preoperative PNI, age, extent of resection, number of gliomas, and MGMT methylation status could predict the prognosis of patients with grade IV glioma well.

Conclusion

The PNI level before surgery was an independent prognostic factor for patients with grade IV glioma. The nomogram covering PNI in patients with grade IV glioma also proved the value of PNI. However, the value of PNI in grade III glioma needs to be further evaluated. More prospective studies are needed to verify this conclusion.

Identification of Circulating lncRNAs Associated with Gallbladder Cancer Risk by Tissue-Based Preselection, Cis-eQTL Validation, and Analysis of Association with Genotype-Based Expression

Long noncoding RNAs (lncRNAs) play key roles in cell processes and are good candidates for cancer risk prediction. Few studies have investigated the association between individual genotypes and lncRNA expression. Here we integrate three separate datasets with information on lncRNA expression only, both lncRNA expression and genotype, and genotype information only to identify circulating lncRNAs associated with the risk of gallbladder cancer (GBC) using robust linear and logistic regression techniques. In the first dataset, we preselect lncRNAs based on expression changes along the sequence "gallstones → dysplasia → GBC". In the second dataset, we validate associations between genetic variants and serum expression levels of the preselected lncRNAs (cis-lncRNA-eQTLs) and build lncRNA expression prediction models. In the third dataset, we predict serum lncRNA expression based on individual genotypes and assess the association between genotype-based expression and GBC risk. AC084082.3 and LINC00662 showed increasing expression levels (p-value = 0.009), while C22orf34 expression decreased in the sequence from gallstones to GBC (p-value = 0.04). We identified and validated two cis-LINC00662-eQTLs (r² = 0.26) and three cis-C22orf34-eQTLs (r² = 0.24). Only LINC00662 showed a genotyped-based serum expression associated with GBC risk (OR = 1.25 per log2 expression unit, 95% CI 1.04-1.52, p-value = 0.02). Our results suggest that preselection of lncRNAs based on tissue samples and exploitation of cis-lncRNA-eQTLs may facilitate the identification of circulating noncoding RNAs linked to cancer risk.

OLFM4 depletion sensitizes gallbladder cancer cells to cisplatin through the ARL6IP1/caspase-3 axis

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OLFM4 is involved in development of gallbladder cancer.

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Depletion of OLFM4 sensitizes gallbladder cancer cells to cisplatin by regulating apoptosis.

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Low expression of OLFM4 in GBC patients indicates longer survival.

Background

Gallbladder cancer (GBC) is a highly lethal malignancy that carries an extremely poor prognosis due to its chemoresistant nature. Cisplatin (CDDP) is a first-line chemotherapeutic for GBC; however, patients experienced no benefit when treated with CDDP alone. The underlying mechanisms of CDDP resistance in GBC remain largely unknown.

Methods

Agilent mRNA microarray analysis was performed between paired GBC and paracarcinoma to explore differentially expressed genes that might underlie drug resistance. Gene Set Enrichment Analysis (GSEA) was employed to identify key genes mediating CDDP resistance in GBC, and immunohistochemistry was performed to validate protein expression and test correlations with clinicopathological features. In vitro and in vivo functional assays were performed to investigate the proteins’ roles in CDDP resistance.

Results

Olfactomedin 4 (OLFM4) was differentially expressed between GBC and paracarcinoma and had the highest rank metric score in the GSEA. OLFM4 expression was increasingly upregulated from chronic cholecystitis to GBC in clinical tissue samples, and OLFM4 depletion decreased GBC cell proliferation and invasion. Interestingly, downregulation of OLFM4 reduced ARL6IP1 (antiapoptotic factor) expression and sensitized GBC cells to CDDP both in vitro and in vivo. The evidence indicated that CDDP could significantly increase Bax and Bad expression and activate caspase-3 cascade in OLFM4-depleted GBC cells through ARL6IP1. Clinically, lower OLFM4 expression was associated with good prognosis of GBC patients.

Conclusions

Our results suggest that OLFM4 is an essential gene that contributes to GBC chemoresistance and could serve as a prognostic biomarker for GBC. Importantly, OLFM4 could be a potential chemotherapeutic target.

Causal role of high body mass index in multiple chronic diseases: a systematic review and meta-analysis of Mendelian randomization studies

BACKGROUND

Obesity is a worldwide epidemic that has been associated with a plurality of diseases in observational studies. The aim of this study was to summarize the evidence from Mendelian randomization (MR) studies of the association between body mass index (BMI) and chronic diseases.

METHODS

PubMed and Embase were searched for MR studies on adult BMI in relation to major chronic diseases, including diabetes mellitus; diseases of the circulatory, respiratory, digestive, musculoskeletal, and nervous systems; and neoplasms. A meta-analysis was performed for each disease by using results from published MR studies and corresponding de novo analyses based on summary-level genetic data from the FinnGen consortium (n = 218,792 individuals).

RESULTS

In a meta-analysis of results from published MR studies and de novo analyses of the FinnGen consortium, genetically predicted higher BMI was associated with increased risk of type 2 diabetes mellitus, 14 circulatory disease outcomes, asthma, chronic obstructive pulmonary disease, five digestive system diseases, three musculoskeletal system diseases, and multiple sclerosis as well as cancers of the digestive system (six cancer sites), uterus, kidney, and bladder. In contrast, genetically predicted higher adult BMI was associated with a decreased risk of Dupuytren's disease, osteoporosis, and breast, prostate, and non-melanoma cancer, and not associated with Alzheimer's disease, amyotrophic lateral sclerosis, or Parkinson's disease.

CONCLUSIONS

The totality of the evidence from MR studies supports a causal role of excess adiposity in a plurality of chronic diseases. Hence, continued efforts to reduce the prevalence of overweight and obesity are a major public health goal.

The Role of Mendelian Randomization Studies in Deciphering the Effect of Obesity on Cancer

Associations of obesity have been established for at least 11 cancer sites in observational studies, though some questions remain as to causality, strength of associations, and timing of associations throughout the life course. In recent years, Mendelian randomization (MR) has provided complementary information to traditional approaches, but the validity requires that the genetic instrumental variables be causally related to cancers only mediated by the exposure. We summarize and evaluate existing evidence from MR studies in comparison with conventional observational studies to provide insights into the complex relationship between obesity and multiple cancers. MR studies further establish the causality of adult obesity with esophageal adenocarcinoma, cancers of the colorectum, endometrium, ovary, kidney, and pancreas, as well as the inverse association of early life obesity with breast cancer. MR studies, which might account for lifelong adiposity, suggest that the associations in observational studies typically based on single measurement may underestimate the magnitude of the association. For lung cancer, MR studies find a positive association with obesity, supporting that the inverse association observed in some conventional observational studies likely reflects reverse causality (loss of lean body mass before diagnosis) and confounding by smoking. However, MR studies have not had sufficient power for gallbladder cancer, gastric cardia cancer, and multiple myeloma. In addition, more MR studies are needed to explore the effect of obesity at different time points on postmenopausal breast cancer and aggressive prostate cancer.

Validation of the 8th Edition American Joint Commission on Cancer (AJCC) Gallbladder Cancer Staging System: Prognostic Discrimination and Identification of Key Predictive Factors

The scope of our study was to compare the predictive ability of American Joint Committee on Cancer (AJCC) 7th and 8th edition in gallbladder carcinoma (GBC) patients, investigate the effect of AJCC 8th nodal status on the survival, and identify risk factors associated with the survival after N reclassification using the National Cancer Database (NCDB) in the period 2005-2015. The cohort consisted of 7743 patients diagnosed with GBC; 202 patients met the criteria for reclassification and were denoted as stage ≥III by AJCC 7th and 8th edition criteria. Overall survival concordance indices were similar for patients when classified by AJCC 8th (OS c-index: 0.665) versus AJCC 7th edition (OS c-index: 0.663). Relative mortality was higher within strata of T1, T2, and T3 patients with N2 compared with N1 stage (T1 HR: 2.258, p < 0.001; T2 HR: 1.607, p < 0.001; Τ3 HR: 1.306, p < 0.001). The risk of death was higher in T1-T3 patients with Nx compared with N1 stage (T1 HR: 1.281, p = 0.043, T2 HR: 2.221, p < 0.001, T3 HR: 2.194, p < 0.001). In patients with AJCC 8th edition stage ≥IIIB GBC and an available grade, univariate analysis showed that higher stage, Charlson-Deyo score ≥ 2, higher tumor grade, and unknown nodal status were associated with an increased risk of death, while year of diagnosis after 2013, academic center, chemotherapy. and radiation therapy were associated with decreased risk of death. Chemotherapy and radiation therapy were associated with decreased risk of death in patients with T3-T4 and T2-T4 GBC, respectively. In conclusion, the updated AJCC 8th GBC staging system was comparable to the 7th edition, with the recently implemented changes in N classification assessment failing to improve the prognostic performance of the staging system. Further prospective studies are needed to validate the T2 stage subclassification as well as to clarify the association, if any is actually present, between advanced N staging and increased risk of death in patients of the same T stage.