Gallbladder cancer in Chile: what have we learned?

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.

Global, regional, and national quality of care of gallbladder and biliary tract cancer: a systematic analysis for the global burden of disease study 1990-2017

BACKGROUND

To improve health outcomes to their maximum level, defining indices to measure healthcare quality and accessibility is crucial. In this study, we implemented the novel Quality of Care Index (QCI) to estimate the quality and accessibility of care for patients with gallbladder and biliary tract cancer (GBBTC) in 195 countries, 21 Global Burden of Disease (GBD) regions, Socio-demographic Index (SDI) quintiles, and sex groups.

METHOD

This cross-sectional study extracted estimates on GBBTC burden from the GBD 2017, which presents population-based estimates on GBBTC burden for higher than 15-year-old patients from 1990 to 2017. Four secondary indices indicating quality of care were chosen, comprising Mortality to incidence, Disability-Adjusted Life Year (DALY) to prevalence, prevalence to incidence, and years of life lost (YLL) to years lived with disability (YLD) ratios. Then, the whole dataset was analyzed using Principal Component Analysis to combine the four indices and create a single all-inclusive measure named QCI. The QCI was scaled to the 0-100 range, with 100 indicating the best quality of care among countries. Gender Disparity Ratio (GDR) was defined as the female to male QCI ratio to show gender inequity throughout the regions and countries.

RESULTS

Global QCI score for GBBTC was 33.5 in 2017, which has increased by 29% since 1990. There was a considerable gender disparity in favor of men (GDR = 0.74) in 2017, showing QCI has moved toward gender inequity since 1990 (GDR = 0.85). Quality of care followed a heterogeneous pattern among regions and countries and was positively correlated with the countries' developmental status reflected in SDI (r = 0.7; CI 95%: 0.61-0.76; P value< 0.001). Accordingly, High-income North America (QCI = 72.4) had the highest QCI; whereas, Eastern Sub-Saharan Africa (QCI = 3) had the lowest QCI among regions. Patients aged 45 to 80 had lower QCI scores than younger and older adults. The highest QCI score was for the older than 95 age group (QCI = 54), and the lowest was for the 50-54 age group (QCI = 26.0).

CONCLUSIONS

QCI improved considerably from 1990 to 2017; however, it showed heterogeneous distribution and inequity between sex and age groups. In each regional context, plans from countries with the highest QCI and best gender equity should be disseminated and implemented in order to decrease the overall burden of GBBTC.

Epigenome-Wide Analysis of Methylation Changes in the Sequence of Gallstone Disease, Dysplasia, and Gallbladder Cancer

BACKGROUND AND AIMS

Gallbladder cancer (GBC) is a highly aggressive malignancy of the biliary tract. Most cases of GBC are diagnosed in low-income and middle-income countries, and research into this disease has long been limited. In this study we therefore investigate the epigenetic changes along the model of GBC carcinogenesis represented by the sequence gallstone disease → dysplasia → GBC in Chile, the country with the highest incidence of GBC worldwide.

APPROACH AND RESULTS

To perform epigenome-wide methylation profiling, genomic DNA extracted from sections of formalin-fixed, paraffin-embedded gallbladder tissue was analyzed using Illumina Infinium MethylationEPIC BeadChips. Preprocessed, quality-controlled data from 82 samples (gallstones n = 32, low-grade dysplasia n = 13, high-grade dysplasia n = 9, GBC n = 28) were available to identify differentially methylated markers, regions, and pathways as well as changes in copy number variations (CNVs). The number and magnitude of epigenetic changes increased with disease development and predominantly involved the hypermethylation of cytosine-guanine dinucleotide islands and gene promoter regions. The methylation of genes implicated in Wnt signaling, Hedgehog signaling, and tumor suppression increased with tumor grade. CNVs also increased with GBC development and affected cyclin-dependent kinase inhibitor 2A, MDM2 proto-oncogene, tumor protein P53, and cyclin D1 genes. Gains in the targetable Erb-B2 receptor tyrosine kinase 2 gene were detected in 14% of GBC samples.

CONCLUSIONS

Our results indicate that GBC carcinogenesis comprises three main methylation stages: early (gallstone disease and low-grade dysplasia), intermediate (high-grade dysplasia), and late (GBC). The identified gradual changes in methylation and CNVs may help to enhance our understanding of the mechanisms underlying this aggressive disease and eventually lead to improved treatment and early diagnosis of GBC.

An overview on possible links between aflatoxin B1 exposure and gallbladder cancer

Gallbladder cancer (GBC) is one of the most common sites for biliary tract cancers. It has a worldwide distribution being endemic in South America and Southern Asia. These high GBC rates have previously been linked to the determinants of health such as nutrition, genetics, lifestyle, and environment. Exposure to aflatoxin B₁ (AFB₁), a human carcinogen, is suggested to be involved with GBC development. This work aims to analyse the interplay of social, lifestyle, and genetic predisposing factors to GBC. AFB₁ plays a pivotal role in carcinogenic onset by genetic and epigenetic modifications. AFB₁ can induce molecular changes involved in the GBC pathogenesis, such as overexpression of UCHL1 gene, mutagenesis of TP53 gene, abnormal expression of oncogenes BCL-2, and aberrantly methylation of ERBB family receptors. However, a large-scale scientific cooperation is needed to confirm these molecular links through which AFB₁ may increase the GBC risk. For that, monitoring AFB₁ exposure through AF-albumin and AFB1-lysine will clarify the level of exposure of the population to AFB₁ in the GBC hotspot. Further, analyses of AFB1-adduct concentrations in GBC cases (fatal and non-fatal) are needed to understanding if AF contamination can trigger gallbladder cancer.

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

BACKGROUND AND AIMS

Gallbladder cancer (GBC) is a neglected disease with substantial geographical variability: Chile shows the highest incidence worldwide, while GBC is relatively rare in Europe. Here, we investigate the causal effects of risk factors considered in current GBC prevention programs as well as C-reactive protein (CRP) level as a marker of chronic inflammation.

APPROACH AND RESULTS

We applied two-sample Mendelian randomization (MR) using publicly available data and our own data from a retrospective Chilean and a prospective European study. Causality was assessed by inverse variance weighted (IVW), MR-Egger regression, and weighted median estimates complemented with sensitivity analyses on potential heterogeneity and pleiotropy, two-step MR, and mediation analysis. We found evidence for a causal effect of gallstone disease on GBC risk in Chileans (P = 9 × 10-5 ) and Europeans (P = 9 × 10-5 ). A genetically elevated body mass index (BMI) increased GBC risk in Chileans (P = 0.03), while higher CRP concentrations increased GBC risk in Europeans (P = 4.1 × 10-6 ). European results suggest causal effects of BMI on gallstone disease (P = 0.008); public Chilean data were not, however, available to enable assessment of the mediation effects among causal GBC risk factors.

CONCLUSIONS

Two risk factors considered in the current Chilean program for GBC prevention are causally linked to GBC risk: gallstones and BMI. For Europeans, BMI showed a causal effect on gallstone risk, which was itself causally linked to GBC risk.

The Evaluation of 17 Gastrointestinal Tumor Markers Reveals Prognosis Value for MUC6, CK17, and CD10 in Gallbladder-Cancer Patients

Gallbladder cancer (GBC) is an aggressive and highly lethal disease with relatively low global incidence, but one that constitutes a major health problem in Asian and Latin American countries, particularly in Chile. The identification of new tumor-associated markers with potential prognosis value is required for GBC clinical practice. Using immunohistochemistry/tumor tissue microarray, we evaluated the expression of 17 gastrointestinal tumor-associated protein markers (CK7, CK17, CK19, CK20, CKLMW, CKHMW, MUC1, MUC2, MUC5AC, MUC6, CA125, CD10, CEA, vimentin, villin, claudin-4, and CDX2) in primary gallbladder adenocarcinomas from 180 Chilean patients and analyzed potential associations with their pathological and clinical characteristics. Younger female patients with well- to moderately differentiated tumors had a better prognosis than that of older female or male patients with tumors with a similar tumor differentiation grade. Among all analyzed markers, MUC6 expression was associated with better prognosis in patients with well- to moderately differentiated tumors, whereas CK17 or CD10 was associated with worse prognosis in patients with poorly differentiated tumors. In addition, the MUC6⁺CK17^– expression pattern was strongly associated with better prognosis in patients with well- to moderately differentiated tumors, whereas patients with poorly differentiated tumors and with the CK17⁺CD10⁺ expression pattern showed worse prognosis. Our results suggest that tumor MUC6, CK17, and CD10 can be considered as potential prognosis markers for GBC.

Cholangiocyte derived carcinomas and local microbiota

Trillions of bacteria are present in the gastrointestinal tract as part of the local microbiota. Bacteria have been associated with a wide range of gastrointestinal diseases including malignant neoplasms. The association of bacteria in gastrointestinal and biliary tract carcinogenesis is supported in the paradigm of Helicobacter pylori and intestinal-type gastric cancer. However, the association of bacterial species to a specific carcinoma, different from intestinal-type gastric cancer is unresolved. The relationship of bacteria to a specific malignant neoplasm can drive clinical interventions. We review the classic bacteria risk factors identified using cultures and PCR (polymerase chain reaction) with new research regarding a microbiota approach through 16S rRNA (16S ribosomal ribonucleic acid gene) or metagenomic analysis for selected carcinomas in the biliary tract.

Cadmium exposure activates Akt/ERK Signaling and pro-inflammatory COX-2 expression in human gallbladder epithelial cells via a ROS dependent mechanism

Gallbladder cancer (GBC) is the commonest biliary tract cancer with an ill-defined etiology. We examined the role of Cd⁺² exposures in a primary human gallbladder (GB) cell line model in this study. Cd⁺² exposures induced decreased cell viability, reactive oxygen species (ROS) generation, altered Akt/ERK signaling pathway activation, PGE₂ and COX-2 expression in a human primary gallbladder epithelial cell model. Pharmacological inhibitors were used to determine the key drivers of elevated COX-2 expression due to Cd⁺² exposure. Our results show Cd⁺² causes a dose-dependent reduction in GB cell viability (EC50 value - 18.6 μM). Dose-dependent activation of phospho-Akt and phospho-ERK signaling pathways via increased phosphoprotein expression was observed due to Cd⁺². Signaling activation of Akt and ERK was prevented by 5 mM N-Acetyl Cysteine (NAC), establishing the role of ROS as a key driver in the activation process. Importantly, we observed Cd⁺² also caused a dose dependent change in the COX-2 and PGE₂ expression levels. PI3K-Akt and NF-kB signaling pathways play a key role in Cd⁺² exposure induced COX-2 activation in the gallbladder epithelial cells. In conclusion, our study measures the toxicological effects of Cd⁺² exposures on human GB epithelial cells for the first time and establishes the role of Cd⁺² as a possible driver of the Akt/ERK pathway overactivity and chronic inflammation in gallbladder carcinogenesis.

Trends of gallbladder cancer incidence, mortality, and diagnostic approach in urban Shanghai between 1973 and 2009

PURPOSE

To describe and interpret secular time trends in gallbladder cancer (GBC) incidence, mortality, and diagnostic approach using 37 years of cancer registry data in urban Shanghai.

METHODS

Data on registration of GBC in urban Shanghai during 1973 and 2009 were collected by the Shanghai Cancer Registry. To describe time trends and to identify specific time points when significant changes occurred, we used joinpoint regression analysis.

RESULTS

The age-standardized rates (ASRs) of incidence increased from 1.1/100,000 (1973-1975) to 2.9/100,000 (2006-2009) in men and from 1.7/100,000 (1973-1975) to 3.9/100,000 (2006-2009) in women. ASRs of incidence increased significantly with estimated annual percent changes (EAPCs) of 2.8% in men and 2.5% in women. The mortality trends increased significantly, with EAPCs of 2.8% in men and 2.5% in women. The increasing incidence and mortality rates were primarily observed in men ⩾60 years of age and in women ⩾70 years of age. Notable downward trends in incidence and mortality were identified among women age 60-69 years over the last decade. The percentage of GBC diagnosed by pathology increased steadily over the years while the percentage of GBC diagnosed by imaging, surgery, and biochemistry sharply increased from 1987 onwards.

CONCLUSIONS

Thirty-seven years of cancer registry data document a tremendous increase in incidence/mortality and a slight decline in incidence/mortality over the last decades for GBC, especially among women, in Shanghai. The development of diagnostic approaches and aging population may play important roles.

Surgical outcomes of primary carcinosarcoma of the gallbladder after curative resection: A rare case series

INTRODUCTION

Primary carcinosarcoma is a rare neoplasm of the gallbladder, and is characterized by collision elements of the adenocarcinomatous and sarcomatous components. The tumours comprise both malignant epithelial and mesenchymal elements, and are usually very aggressive, conferring poor prognosis. Adenocarcinomas are the most common neoplasms of the gall bladder, while carcinosarcoma are extremely rare, with a global prevalence rate of less than 1%. The low incidence of carcinosarcoma greatly hinders the understanding of its aetiology.

PRESENTATION OF CASE

Here, we report the surgical outcome of 3 rare cases of gallbladder carcinosarcomas, two of which had a IVB stage disease and in one case the staging was II. Following surgery, the survival in the former was less than 1 year, while in the latter, it extended up to 7 years (86 months), and the patient is alive till date. This study aimed to elucidate the surgical outcomes and prognosis after curable resection for carcinosarcomas of the gallbladder.

DISCUSSION

The findings suggest that carcinosarcomas are associated with a poor prognosis and short survival, particularly in those with tumours of >5 cm. In the absence of effective adjuvant treatment, surgery remains the mainstay of treatment.

CONCLUSION

Complete surgical resection may improve prognosis and extend survival in patients with this rare and aggressive form of gallbladder cancer.

Gallbladder cancer: review of a rare orphan gastrointestinal cancer with a focus on populations of New Mexico

Gallbladder cancer is a rare malignancy of the biliary tract with a poor prognosis, frequently presenting at an advanced stage. While rare in the United States overall, gallbladder cancer has an elevated incidence in geographically distinct locations of the globe including Chile, North India, Korea, Japan and the state of New Mexico in the United States. People with Native American ancestry have a much elevated incidence of gallbladder cancer compared to Hispanic and non-Hispanic white populations of New Mexico. Gallbladder cancer is also one of the few bi-gendered cancers with an elevated female incidence compared to men. Similar to other gastrointestinal cancers, gallbladder cancer etiology is likely multi-factorial involving a combination of genomic, immunological, and environmental factors. Understanding the interplay of these unique epidemiological factors is crucial in improving the prevention, early detection, and treatment of this lethal disease. Previous studies have failed to identify a distinct genomic mutational profile in gallbladder cancers, however, work to identify promising clinically actionable targets is this form of cancer is ongoing. Examples include, interest in the HER2/Neu signaling pathway and the recognition that chronic inflammation plays a crucial role in gallbladder cancer pathogenesis. In this review, we provide a comprehensive overview of gallbladder cancer epidemiology, risk factors, pathogenesis, and treatment with a specific focus on the rural and Native American populations of New Mexico. We conclude this review by discussing future research directions with the goal of improving clinical outcomes for patients of this lethal malignancy.

Tumor lysate-based vaccines: on the road to immunotherapy for gallbladder cancer

Immunotherapy based on checkpoint blockers has proven survival benefits in patients with melanoma and other malignancies. Nevertheless, a significant proportion of treated patients remains refractory, suggesting that in combination with active immunizations, such as cancer vaccines, they could be helpful to improve response rates. During the last decade, we have used dendritic cell (DC) based vaccines where DCs loaded with an allogeneic heat-conditioned melanoma cell lysate were tested in a series of clinical trials. In these studies, 60% of stage IV melanoma DC-treated patients showed immunological responses correlating with improved survival. Further studies showed that an essential part of the clinical efficacy was associated with the use of conditioned lysates. Gallbladder cancer (GBC) is a high-incidence malignancy in South America. Here, we evaluated the feasibility of producing effective DCs using heat-conditioned cell lysates derived from gallbladder cancer cell lines (GBCCL). By characterizing nine different GBCCLs and several fresh tumor tissues, we found that they expressed some tumor-associated antigens such as CEA, MUC-1, CA19-9, Erb2, Survivin, and several carcinoembryonic antigens. Moreover, heat-shock treatment of GBCCLs induced calreticulin translocation and release of HMGB1 and ATP, both known to act as danger signals. Monocytes stimulated with combinations of conditioned lysates exhibited a potent increase of DC-maturation markers. Furthermore, conditioned lysate-matured DCs were capable of strongly inducing CD4⁺ and CD8⁺ T cell activation, in both allogeneic and autologous cell co-cultures. Finally, in vitro stimulated CD8⁺ T cells recognize HLA-matched GBCCLs. In summary, GBC cell lysate-loaded DCs may be considered for future immunotherapy approaches.

Circulating inflammatory proteins and gallbladder cancer: Potential for risk stratification to improve prioritization for cholecystectomy in high-risk regions

BACKGROUND

Inflammatory proteins could help identify individuals most likely to have gallbladder cancer (GBC) among those waiting for cholecystectomy.

METHODS

We analyzed 49 circulating inflammation-related proteins in 144 patients with GBC and 150 patients with gallstones. We calculated age- and sex-adjusted odds ratios (ORs) and 95% CIs for protein quantiles and GBC versus gallstones. Using proteins associated with early GBC (stage 1-2) that were selected in stepwise logistic regression, we created an inflammation score and explored the potential utility for risk stratification.

RESULTS

26 proteins (53%) had P values for the trend across categories ≤0.001, with associations for a one category increase ranging from 1.52 (95% CI: 1.20-1.94) for CC motif ligand 4 to 4.00 (95% CI: 2.76-5.79) for interleukin (IL)-8. Soluble tumor necrosis factor receptor 2 (sTNFR2), IL-6, sTNFR1, CC motif ligand 20 (CCL20), vascular cell adhesion molecule 1, IL-16, and granulocyte colony-stimulating factor had P values ≤0.001 for early GBC. Of those, IL-6, IL-16, CCL20, and STNFR1 were included in the inflammation score. In a high-risk setting with a pre-test disease risk of 10% (e.g., elderly patients) and using an inflammation score cutoff that provides 90% sensitivity, 39% of patients on the waiting list would be predicted to be positive, and 23% of those would be predicted to have GBC.

CONCLUSION

These results highlight the strong associations of inflammatory proteins with GBC risk and their potential clinical utility. Larger studies are needed to identify the most effective combinations of inflammatory proteins for detecting early GBC and precursor lesions.

High CD8+ and absence of Foxp3+ T lymphocytes infiltration in gallbladder tumors correlate with prolonged patients survival

BACKGROUND

Gallbladder cancer (GBC), although infrequent in industrialized countries, has high incidence rates in certain world regions, being a leading cause of death among elderly Chilean women. Surgery is the only effective treatment, and a five-year survival rate of advanced-stage patients is less than 10%. Hence, exploring immunotherapy is relevant, although GBC immunogenicity is poorly understood. This study examined the relationship between the host immune response and GBC patient survival based on the presence of tumor-infiltrating lymphocytes at different disease stages.

METHODS

Tumor tissues from 80 GBC patients were analyzed by immunohistochemistry for the presence of CD3+, CD4+, CD8+, and Foxp3+ T cell populations, and the results were associated with clinical stage and patient survival.

RESULTS

The majority of tumor samples showed CD3+ T cell infiltration, which correlated with better prognosis, particularly in advanced disease stages. CD8+, but not CD4+, T cell infiltration correlated with improved survival, particularly in advanced disease stages. Interestingly, a < 1 CD4+/CD8+ T cell ratio was related with increased survival. Additionally, the presence of Foxp3+ T cells correlated with decreased patient survival, whereas a ≤ 1 Foxp3+/CD8+ T cell ratio was associated with improved patient survival.

CONCLUSIONS

Depending on the disease stage, the presence of CD8+ and absence of Foxp3+ T cell populations in tumor tissues correlated with improved GBC patient survival, and thus represent potential markers for prognosis and management of advanced disease, and supports testing of immunotherapy.