The antecedents of biliary cancer: a primary care case-control study in the United Kingdom. Br J Cancer. 2009;100:178-180. [PMID: 19018260 PMCID: PMC2634685 DOI: 10.1038/sj.bjc.6604765]

Interplay of Cardiometabolic Syndrome and Biliary Tract Cancer: A Comprehensive Analysis with Gender-Specific Insights

BTC overall incidence is globally increasing. CCA, including its subtypes, is a form of BTC. MetS, obesity, MASLD, and diabetes are all linked to CCA in interconnected ways. The link between obesity and CCA is less well-defined in Eastern countries as compared to Western. Although more research is needed to determine the relationship between MASLD and extrahepatic CCA (eCCA), MASLD may be a concurrent risk factor for intrahepatic CCA, particularly in populations with established or unidentified underlying liver disease. Interestingly, the risk of biliary tract cancer (BTC) seemed to be higher in patients with shorter diabetes durations who were not treated with insulin. Therefore, early detection and prevention of chronic liver disease, as well as additional intervention studies, will undoubtedly be required to determine whether improvements to MetS, weight loss, and diabetes therapy can reduce the risk and progression of BTC. However, further studies are needed to understand how reproductive hormones are involved in causing BTC and to develop consistent treatment for patients. Finally, it is critical to carefully assess the cardiological risk in BTC patients due to their increased intrinsic cardiovascular risk, putting them at risk for thrombotic complications, cardiovascular death, cardiac metastasis, and nonbacterial thrombotic endocarditis. This review aimed to provide an updated summary of the relation between the abovementioned cardio-metabolic conditions and BTC.

Evidence-based clinical practice guidelines for cholelithiasis 2021

The Japanese Society of Gastroenterology first published evidence-based clinical practice guidelines for cholelithiasis in 2010, followed by a revision in 2016. Currently, the revised third edition was published to reflect recent evidence on the diagnosis, treatment, and prognosis of cholelithiasis conforming to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Following this revision, the present English version of the guidelines was updated and published herein. The clinical questions (CQ) in the previous version were reviewed and rearranged into three newly divided categories: background questions (BQ) dealing with basic background knowledge, CQ, and future research questions (FRQ), which refer to issues that require further accumulation of evidence. Finally, 52 questions (29 BQs, 19 CQs, and 4 FRQs) were adopted to cover the epidemiology, pathogenesis, diagnosis, treatment, complications, and prognosis. Based on a literature search using MEDLINE, Cochrane Library, and Igaku Chuo Zasshi databases for the period between 1983 and August 2019, along with a manual search of new information reported over the past 5 years, the level of evidence was evaluated for each CQ. The strengths of recommendations were determined using the Delphi method by the committee members considering the body of evidence, including benefits and harms, patient preference, and cost-benefit balance. A comprehensive flowchart was prepared for the diagnosis and treatment of gallbladder stones, common bile duct stones, and intrahepatic stones, respectively. The current revised guidelines are expected to be of great assistance to gastroenterologists and general physicians in making decisions on contemporary clinical management for cholelithiasis patients.

The causal relationship between metabolic factors, drinking, smoking and intrahepatic cholangiocarcinoma: a Mendelian randomization study

Background

Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver cancer. While multiple risk factors for iCCA have been established, metabolic diseases (obesity, diabetes, NAFLD, dyslipidemia, and hypertension) and other risk factors, including smoking and drinking, are still controversial due to their potential confounders. Here, Mendelian randomization (MR) analysis was performed to identify the causal relationship between them.

Method

In this study, we obtained GWAS data related to exposures from corresponding large genome-wide association studies. Summary-level statistical data for iCCA were obtained from the UK Biobank (UKB). We performed a univariable MR analysis to identify whether genetic evidence of exposure was significantly associated with iCCA risk. A multivariable MR analysis was conducted to estimate the independent effects of exposures on iCCA.

Results

Univariable and multivariable MR analysis based on the large GWAS data indicated that there is little evidence to support the genetic role of metabolic factors, smoking, drinking, and NAFLD in iCCA development (P >0.05). In contrast to most current studies, their impact on iCCA development, if any, might be smaller than we thought. The previous positive results might be due to the comorbidities between diseases and potentially unavoidable confounding factors.

Conclusion

In this MR study, we found no strong evidence to support causal associations between metabolic factors, NAFLD, smoking, drinking, and iCCA risk.

Immunology and immunotherapy of cholangiocarcinoma

Cholangiocarcinoma is the second most common primary liver cancer. Its incidence is low in the Western world but is rising globally. Surgery, chemotherapy and radiation therapy have been the only treatment options for decades. Progress in our molecular understanding of the disease and the identification of druggable targets, such as IDH1 mutations and FGFR2 fusions, has provided new treatment options. Immunotherapy has emerged as a potent strategy for many different types of cancer and has shown efficacy in combination with chemotherapy for cholangiocarcinoma. In this Review, we discuss findings related to key immunological aspects of cholangiocarcinoma, including the heterogeneous landscape of immune cells within the tumour microenvironment, the immunomodulatory effect of the microbiota and IDH1 mutations, and the association of immune-related signatures and patient outcomes. We introduce findings from preclinical immunotherapy studies, discuss future immune-mediated treatment options, and provide a summary of results from clinical trials testing immune-based approaches in patients with cholangiocarcinoma. This Review provides a thorough survey of our knowledge on immune signatures and immunotherapy in cholangiocarcinoma.

Light-to-Moderate Alcohol Consumption Increases the Risk of Biliary Tract Cancer in Prediabetes and Diabetes, but Not in Normoglycemic Status: A Nationwide Cohort Study

PURPOSE

To determine whether the dose-response association between alcohol consumption and the risk of biliary tract cancer (BTC), including cholangiocarcinoma (CCA) and gallbladder cancer (GBC), differs according to glycemic status.

PATIENTS AND METHODS

This nationwide cohort study included 9,520,629 individuals age ≥ 20 years without a history of cancer who underwent national health screening under the Korean National Health Insurance Service in 2009. The participants were followed up until December 2018 for BTC development. Cox proportional hazard regression analysis was performed to estimate risk.

RESULTS

During the 78.3 million person-years of follow-up, 21,079 patients were newly diagnosed with BTC. In individuals with prediabetes and diabetes, light-to-moderate alcohol consumption increased the risk of CCA (adjusted hazard ratio [aHR], 1.20; 95% CI, 1.13 to 1.28 and aHR, 1.58; 95% CI, 1.47 to 1.69) and GBC (aHR, 1.18; 95% CI, 1.07 to 1.31 and aHR, 1.45; 95% CI, 1.28 to 1.64). In normoglycemic individuals, light-to-moderate alcohol consumption was not associated with CCA or GBC risk. When heavy alcohol consumption was combined with diabetes, CCA and GBC risk increased synergistically (aHR, 2.04; 95% CI, 1.83 to 2.26; and aHR, 1.65; 95% CI, 1.33 to 2.04, respectively; all P < .001). Prediabetes and heavy alcohol consumption had a synergistic interactive effect on CCA and GBC risks (all P < .001). Comparable results were obtained for intrahepatic and extrahepatic CCA analyses.

CONCLUSION

Even light-to-moderate alcohol consumption was associated with an increased risk of BTC in individuals with prediabetes and diabetes, but not in normoglycemic individuals. Complete avoidance of alcohol consumption may help reduce the risk of BTC in patients with prediabetes and diabetes, suggesting the need for individualized prevention strategies for BTC.

Pharmacophore Based Design of Probable FGFR-1 Inhibitors from the 3D Crystal Structure of Infigratinib - A Drug Used in the Treatment of Cholangiocarcinomas

Background:

Pemigatinib (INCB054828) and Infigratinib (BGJ398) are the few selective drugs that are approved by the FDA to treat cholangiocarcinoma, a rare form of bile duct cancer. Infigratinib is a pan FGFR inhibitor and has been found promising in Phase-3, first-line PROOF clinical trial. So, screening drug-like compounds having similar pharmacophoric features like infigratinib is the inspiration of the present work.

Objective:

The objective was to identify drug-like compounds with similar pharmacophoric features as in infigratinib. The compounds screened through the 3D query pharmacophore of infigratinib were also predicted for ADMET properties so that the compounds may have good bioavailability.

Method:

A pharmacophore was generated from the crystal structure of infigratinib with several pharmacophoric features such as hydrogen bond donor, hydrophobic, positive ionizable, and ring aromatic. MayBridge database containing 65,263 compounds was used for virtual screening (VS) using LibDock. The initial Hit compounds were subjected to ADMET predictions. Finally, two Hit compounds were selected and docked with the FGFR-1 receptor to predict the interaction of the ligand atoms with the amino acid residues of the receptor's active site.

Result:

The fit score for infigratinib, N-(4-fluorophenyl)-2-(5-((2-(4-methoxy-2,5-dimethylphenyl)-2- oxoethyl)thio)-4-methyl-4H-1,2,4-triazol-3-yl)acetamide (Hit-1) and 4-(4-((2-(5,6-dimethyl-1H-benzo[d] imidazol-2-yl)ethyl)carbamoyl)pyridin-2-yl)-1-methylpiperazin-1-ium (Hit-4) is 4.58901, 4.36649, and 3.71732, respectively. The LibDock score of infigratinib, Hit-1, and Hit-4 is 122.474, 123.289, and 123.353, respectively. The binding affinity score (-PLP1) of infigratinib, Hit-1, and Hit-4 is -143.19, - 102.72, and -91.71.

Conclusion:

The present study concluded that the two compounds designated as Hit-1 and Hit-4 have been identified as binders of FGFR-1, and Hit-4 occupies the whole pharmacophoric space of infigratinib, and both the compounds LibDock scores are better than the infigratinib. The two compounds Hit-1 and Hit-4 may be synthesized and studied for their enzyme inhibition assay on FGFR-1 and biologically evaluated on different cell lines for Cholangiocarcinoma.

Controversial risk factors for cholangiocarcinoma

INTRODUCTION

Cholangiocarcinoma is a rare malignancy accounting for 3% of gastrointestinal cancers in the USA. While multiple risk factors for cholangiocarcinoma are established, other potential risk factors are still controversial. Herein, we used a large national database to investigate possible risk factors and associations.

METHOD

We used the National Inpatient Sample database to review all admissions between 2011 and 2015. We grouped patients based on the presence and absence of cholangiocarcinoma. Using multivariate logistic regression analysis, we assessed the association between obesity, alcohol abuse, smoking, diabetes mellitus and cholangiocarcinoma.

RESULTS

Out of 30 9552 95 admissions, 20 030 had cholangiocarcinoma. Cholangiocarcinoma patients were older (67 ± 12.8 vs. 57 ± 20.6; P < 0.001) and had fewer female patients (48 vs. 59%; P < 0.001). Multivariate logistic regression analysis showed that diabetes mellitus was associated with cholangiocarcinoma (OR, 1.04; 95% CI, 1.01-1.08; P < 0.001). On the other hand, alcohol, smoking and obesity were all inversely associated with cholangiocarcinoma (OR, 0.75; 95% CI, 0.69-0.81; P < 0.001), (OR, 0.75; 95% CI, 0.71-0.79; P < 0.001) and (OR, 0.71; 95% CI, 0.67-0.75; P < 0.001), respectively. In addition, compared to Whites, Hispanic and Asian/Pacific Islander races were more associated with cholangiocarcinoma (OR, 1.27; 95% CI, 1.21-1.34) and (OR, 1.79; 95% CI, 1.67-1.92) (P < 0.001 for all), respectively, whereas African American race was inversely associated with cholangiocarcinoma (OR, 0.85; 95% CI, 0.81-0.89; P < 0.001).

CONCLUSION

Patients with a diagnosis of diabetes mellitus or from certain ethnic groups (Hispanic and Asian/Pacific Islander) are associated with increased risk for cholangiocarcinoma.

Aspirin, statins, non-aspirin NSAIDs, metformin and the risk of Biliary Cancer: A Swedish population-based cohort study

BACKGROUND

Chemoprevention for biliary tract cancers (BTCs), which comprise intrahepatic cholangiocarcinoma (iCCA), extrahepatic cholangiocarcinoma (eCCA) and gallbladder cancer (GBC), is controversial. We examined associations between low-dose aspirin, statins, NSAIDs, and metformin with BTC risk.

METHODS

We used a population-based cohort of 5.7 million persons over age 18 without personal history of cancer (except non-melanoma skin cancer), receiving at least one commonly-prescribed drug between July 1, 2005, and December 31, 2012, from the Swedish Prescribed Drug Registry. Hazard ratios (HRs) were calculated using age-scaled multivariable-adjusted Cox models.

RESULTS

2,160 individuals developed BTC. Low-dose aspirin was not associated with BTC risk (HR 0.93; 95%CI:0.81-1.07), iCCA (HR 1.21; 95%CI:0.93-1.57), eCCA (HR 0.80; 95%CI:0.60-1.07) or GBC (HR 0.87; 95%CI:0.71-1.06). Statins were associated with lower risk of BTC (HR 0.66; 95%CI:0.56-0.78), iCCA (HR 0.69; 95%CI:0.50-0.95), eCCA (HR 0.54; 95%CI:0.38-0.76), and GBC (HR 0.72; 95%CI:0.57-0.91). For all BTC subtypes, combined low-dose aspirin and statins were not associated with lower risk than statins alone. NSAIDs were associated with higher risk of BTC and its subtypes. Metformin was not associated with BTC risk (HR 0.98; 95%CI:0.82-1.18), iCCA (HR 1.06; 95%CI:0.77-1.48), eCCA (HR 1.15; 95%CI:0.82-1.61) or GBC (HR 0.84; 95%CI:0.63-1.11).

CONCLUSION

Statins were associated with a decreased risk of BTC and its subtypes. Low-dose aspirin alone was not associated with a decreased risk and use of both was not associated with further decrease in risk beyond statins alone.

IMPACT

Statins were most consistently associated with a decreased risk of BTC and its subtypes.

Metabolic disorders and the risk of cholangiocarcinoma

Introduction: Cholangiocarcinoma (CCA) is a malignancy which arises from the biliary epithelium. Carcinogenesis of CCA is mainly linked to aberrant glucose metabolism and creation of an immunosuppressive environment around normal biliary epithelium. The incidence of CCA is higher in the East due to Opisthorchis viverrini, an endemic liver fluke. CCA has also be attributed to genetic, metabolic, and lifestyle risk factors.Areas covered: Differences in epidemiological risk factors are associated with varying phenotypes of CCA. Metabolic risk factors include diabetes, obesity, nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), dyslipidemia, and metabolic syndrome. Inherited metabolic risk factors include Wilson's disease and hemochromatosis. Metabolic disease is associated with a higher risk of CCA, with higher risk for the intrahepatic form. In this review, the authors provide an overview of available evidence regarding metabolic conditions associated with the development of CCA.Expert opinion: Metabolic disease is associated with a higher risk of intrahepatic CCA compared to its extrahepatic or hilar counterpart. As rates of obesity and metabolic syndrome increase, particularly in the West, it is conceivable that the incidence of CCA will also rise in the next years.

Obesity and cholangiocarcinoma: A review of epidemiological and molecular associations

Cholangiocarcinoma (CCA) is a malignancy of bile duct epithelium, and its incidence is increasing globally. Numerous factors are reported associated with an increased risk of CCA and vary among populations across different areas. Obesity is a major, worldwide public health problem that leads to several complications and is associated with increased cancer risk. Although several epidemiological studies have shown that obesity is likely associated with the increased risk of CCA, this association might be limited to Western countries. Multiple hormones, cytokines, and metabolite perturbations in obese states have been shown to enhance tumorigenicity and metastasis potentials. Understanding the biological linkage of obesity to CCA might lead to novel prevention and therapeutic approaches to CCA treatment. This review summarizes the current evidence and highlights the knowledge gaps regarding the relationship between obesity and CCA from epidemiological and molecular perspectives.

Association between gallstones and the risk of biliary tract cancer: a systematic review and meta-analysis

OBJECTIVES

Biliary tract cancers (BTCs) are rare but highly fatal. Although the etiology of BTC is poorly understood, gallstones are proposed to be a major risk factor. We conducted a systematic review and meta-analysis to examine the associations between gallstone characteristics and BTC risk.

METHODS

We searched the MEDLINE, Embase, and Cochrane Central databases and systematically reviewed cohort and case-control studies published before April 9, 2018. All the included studies reported appropriate risk estimates and confidence intervals (CIs) for associations between the presence, size, number, or duration of gallstones and the risk of BTC, including gallbladder cancer (GBC), extrahepatic bile duct cancer (EBDC), and ampulla of Vater cancer (AOVC). Summary odds ratios (ORs) and their 95% CIs were calculated using a random-effects model in the meta-analysis. Subgroup analyses were conducted to inspect sources of potential heterogeneity, and the Egger test was performed to assess publication bias.

RESULTS

Seven cohort studies and 23 case-control studies in Asian, European, and American populations were included. The presence of gallstones was associated with an increased risk of BTC (OR, 4.38; 95% CI, 3.23 to 5.93; I2=91.2%), GBC (OR, 7.26; 95% CI, 4.33 to 12.18), EBDC (OR, 3.17; 95% CI, 2.24 to 4.50), and AOVC (OR, 3.28; 95% CI, 1.33 to 8.11). Gallstone size (>1 vs. <1 cm; OR, 1.88; 95% CI, 1.10 to 3.22) was significantly associated with the risk of GBC.

CONCLUSIONS

Gallstone characteristics, such as presence, size, and number, are associated with an increased risk of BTC. However, significantly high heterogeneity in the meta-analyses is a limitation of this study.

Clinical Ontologies Improve Case Finding of Primary Biliary Cholangitis in UK Primary and Secondary Care

INTRODUCTION

PBC registries in the UK focus on data from secondary care without clear coordinated contribution from primary care. The Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) receives data from > 500 primary care practices (PCPs). Notably, the Lancet commissioning group is extracting data from the RCGP RSC database to shape UK policy on liver disease.

AIMS

To create a novel ontology to facilitate PBC case finding from primary care provider (PCP) records.

METHODS

RCGP RSC data were collected from participating PCPs in the county of Surrey, UK. PBC diagnostic criteria of the AASLD and EASL guidelines were used to develop 725 data codes to facilitate patient record searches. A scoring system built into the ontology allowed categorization of cases as PBC definite, PBC probable, and PBC unlikely.

RESULTS

A total of 218,099 records were searched from participating PCPs. Of these, there were 58 PBC definite, 2317 PBC probable, and 215,724 PBC unlikely patients. There were 32 PBC definite patients who did not match to our regional PBC database and were henceforth included as new-found cases. Two of these cases were not labeled as PBC by the PCP. From the PBC unlikely group, 7/215,724 (0.003%) patients were labeled as PBC in secondary care records; however, none of them were coded as having PBC by their PCPs.

CONCLUSIONS

Utilization of the UK National RCGP RSC database supported by novel ontology score has successfully helped us identify (i) new cases of PBC not known to local/regional secondary care providers and (ii) de novo PBC cases. There are many PBC probable cases whose data merit further careful evaluation.

Obesity and liver cancer

Obesity prevalence is rapidly increasing worldwide. It is associated with huge economic and health costs due to its clinical consequences, which includes increased incidence of type 2 diabetes, cardiovascular diseases, and development of different malignancies. In particular, obesity is an independent risk factor for the development of hepatocellular carcinoma (HCC). Indeed, obesity is highly prevalent in patients with non-alcoholic fatty liver disease (NAFLD) that is becoming one of the most frequent causes of liver disease worldwide. NAFLD-related HCC is the most rapidly growing indication for liver transplantation in many countries. The higher mortality rates found in obese HCC patients might be related not only to a worse outcome after HCC treatments, but also to a delayed diagnosis related to a low frequency and a poorer quality of abdominal ultrasonography surveillance that is the test universally used for HCC screening. Given its diffusion, obesity is frequently present in patients with chronic liver diseases related to different etiologies, and in these cases it may increase the HCC risk, acting as an additional co-factor. Indeed, growing evidence demonstrates that a healthy diet and regular physical activity may have an impact in reducing the overall HCC risk. Finally, an impact of obesity in the development of intrahepatic cholangiocarcinoma has been postulated, but more extensive studies are needed to definitively confirm this association.

Smoking, Alcohol, and Biliary Tract Cancer Risk: A Pooling Project of 26 Prospective Studies

BACKGROUND

Tobacco and alcohol are well-established risk factors for numerous cancers, yet their relationship to biliary tract cancers remains unclear.

METHODS

We pooled data from 26 prospective studies to evaluate associations of cigarette smoking and alcohol consumption with biliary tract cancer risk. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) for associations with smoking and alcohol consumption were calculated. Random-effects meta-analysis produced summary estimates. All statistical tests were two-sided.

RESULTS

Over a period of 38 369 156 person-years of follow-up, 1391 gallbladder, 758 intrahepatic bile duct, 1208 extrahepatic bile duct, and 623 ampulla of Vater cancer cases were identified. Ever, former, and current smoking were associated with increased extrahepatic bile duct and ampulla of Vater cancers risk (eg, current vs never smokers HR = 1.69, 95% CI = 1.34 to 2.13 and 2.22, 95% CI = 1.69 to 2.92, respectively), with dose-response effects for smoking pack-years, duration, and intensity (all Ptrend < .01). Current smoking and smoking intensity were also associated with intrahepatic bile duct cancer (eg, >40 cigarettes per day vs never smokers HR = 2.15, 95 % CI = 1.15 to 4.00; Ptrend = .001). No convincing association was observed between smoking and gallbladder cancer. Alcohol consumption was only associated with intrahepatic bile duct cancer, with increased risk for individuals consuming five or more vs zero drinks per day (HR = 2.35, 95%CI = 1.46 to 3.78; Ptrend = .04). There was evidence of statistical heterogeneity among several cancer sites, particularly between gallbladder cancer and the other biliary tract cancers.

CONCLUSIONS

Smoking appears to increase the risk of developing all biliary tract cancers except gallbladder cancer. Alcohol may increase the risk of intrahepatic bile duct cancer. Findings highlight etiologic heterogeneity across the biliary tract.

Atypical presentation of intrahepatic cholangiocarcinoma---Fever and ascites in a postpartum lady

Intrahepatic cholangiocarcinoma is an uncommon malignancy which usually occurs in the 7th decade. Here we present a postpartum patient with fever, hepatomegaly, and ascites, who was diagnosed to have metastatic intrahepatic cholangiocarcinoma.

Anthropometric Risk Factors for Cancers of the Biliary Tract in the Biliary Tract Cancers Pooling Project

Biliary tract cancers are rare but highly fatal with poorly understood etiology. Identifying potentially modifiable risk factors for these cancers is essential for prevention. Here we estimated the relationship between adiposity and cancer across the biliary tract, including cancers of the gallbladder (GBC), intrahepatic bile ducts (IHBDC), extrahepatic bile ducts (EHBDC), and the ampulla of Vater (AVC). We pooled data from 27 prospective cohorts with over 2.7 million adults. Adiposity was measured using baseline body mass index (BMI), waist circumference, hip circumference, waist-to-hip, and waist-to-height ratios. HRs and 95% confidence intervals (95% CI) were estimated using Cox proportional hazards models adjusted for sex, education, race, smoking, and alcohol consumption with age as the time metric and the baseline hazard stratified by study. During 37,883,648 person-years of follow-up, 1,343 GBC cases, 1,194 EHBDC cases, 784 IHBDC cases, and 623 AVC cases occurred. For each 5 kg/m2 increase in BMI, there were risk increases for GBC (HR = 1.27; 95% CI, 1.19-1.36), IHBDC (HR = 1.32; 95% CI, 1.21-1.45), and EHBDC (HR = 1.13; 95% CI, 1.03-1.23), but not AVC (HR = 0.99; 95% CI, 0.88-1.11). Increasing waist circumference, hip circumference, waist-to-hip ratio, and waist-to-height ratio were associated with GBC and IHBDC but not EHBDC or AVC. These results indicate that adult adiposity is associated with an increased risk of biliary tract cancer, particularly GBC and IHBDC. Moreover, they provide evidence for recommending weight maintenance programs to reduce the risk of developing these cancers. SIGNIFICANCE: These findings identify a correlation between adiposity and biliary tract cancers, indicating that weight management programs may help minimize the risk of these diseases.

Epidemiology of gallbladder cancer

According to GLOBOCAN 2018 data, gallbladder cancer (GBC) accounts for 1.2% of all global cancer diagnoses, but 1.7% of all cancer deaths. Only 1 in 5 GBC cases in the United States is diagnosed at an early stage, and median survival for advanced stage cancer is no more than about a year. The incidence of the disease is increasing in the developed world. Gallstones, biliary cysts, carcinogen exposure, typhoid, and Helicobacter pylori infection, and abnormal pancreaticobiliary duct junctions are all risk factors, many of which account for its geographical, ethnic and sex distribution. Genetics also plays a strong role, as about a quarter of GBC cases are considered familial, and certain ethnicities, such as Native Americans, are at far higher risk for the neoplasm. Prevention includes weight loss, vaccination against and treatment of bacterial infections, early detection and elimination of polyps and cysts, and avoidance of oral estrogen replacement therapy.

Metformin Induces Apoptosis and Inhibits Proliferation through the AMP-Activated Protein Kinase and Insulin-like Growth Factor 1 Receptor Pathways in the Bile Duct Cancer Cells

Background/Aims: Metformin has been found to have antineoplastic activity in some cancer cells. This study was performed to determine whether metformin inhibits the proliferation of bile duct cancer cells by inducing apoptosis and its effects on the expression of gene-related proteins involved in cancer growth.

Methods: Human extrahepatic bile duct cancer cells (SNU-245 and SNU-1196) were cultured. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were performed to determine the effect of metformin on the cell proliferation. Apoptosis was measured by a cell death detection enzyme-linked immunosorbent assay and a caspase-3 activity assay. Expression levels of various proteins, with or without specific small interfering ribonucleic acid-induced gene disruption, were measured by Western blot analysis. The migratory activity of the cancer cells was evaluated by wound healing assay.

Results: Metformin suppressed cell proliferation in bile duct cancer cells by inducing apoptosis. Metformin inhibited mammalian target of rapamycin (mTOR) by activation of tuberous sclerosis complex 2 (TSC-2) through phosphorylation of adenosine monophosphate-activated protein kinase at threonine-172 (AMPK^Thr172). Hyperglycemia impaired metformin-induced AMPK^Thr172 activation and enhanced phosphorylation of AMPK at serine-485 (AMPK^Ser485). Metformin blocked the inhibitory effect of insulin-like growth factor 1 receptor (IGF-1R)/insulin receptor substrate 1 (IRS-1) pathway on TSC-2, and hyperglycemia impaired metformin-induced inhibition of IGF-1R/IRS-1 pathway and modulated the invasiveness of bile duct cancer cells; however, this effect was impaired by hyperglycemia.

Conclusions: Metformin has antineoplastic effects in bile duct cancer, and hyperglycemic environment interrupts the effect of metformin. In addition, AMPK and IGF-1R play a key role in the proliferation of bile duct cancer cells.

Impact of body mass index on tumor recurrence among patients undergoing curative-intent resection of intrahepatic cholangiocarcinoma- a multi-institutional international analysis

BACKGROUND

The association between body mass index (BMI) and long-term outcomes of patients with ICC has not been well defined. We sought to define the presentation and oncologic outcomes of patients with ICC undergoing curative-intent resection, according to their BMI category.

METHODS

Patients who underwent resection of ICC were identified in a multi-institutional database. Patients were categorized as normal weight (BMI 18.5-24.9 kg/m²), overweight (BMI 25.0-29.9 kg/m²) and obese (BMI≥30 kg/m²) according to the World Health Organization (WHO) definition. Impact of clinico-pathological factors on recurrence-free survival (RFS) was assessed using Cox proportional hazards model among patients in the three BMI categories.

RESULTS

Among a total of 790 patients undergoing curative-intent resection of ICC in the analytic cohort, 399 (50.5%) had normal weight, 274 (34.7%) were overweight and 117 (14.8%) were obese. Caucasian patients were more likely to be obese (66.7%, n = 78) and overweight (47.1%, n = 129) compared with Asian (obese: 18.8%, n = 22; overweight: 46%, n = 126) and other races (obese: 14.5%, n = 17; overweight: 6.9%, n = 19)(p < 0.001). There were no differences in the presence of cirrhosis (10.9%, vs. 12.8%, vs. 12.9%), preoperative jaundice (8.6% vs. 9.5% vs. 12.0%), or levels of CA 19-9 (75, IQR 24.6-280 vs. 50.9, IQR 17.9-232 vs. 43, IQR 16.9-192.7) among the BMI groups (all p > 0.05). On multivariable analysis, increased BMI was an independent risk factor for tumor recurrence (OR 1.16, 95% CI 1.02-1.32, for every 5 unit increase).

CONCLUSION

Increasing BMI was associated with incremental increases in the risk of recurrence following curative-intent resection of ICC. Future studies should aim to achieve a better understanding of BMI-related factors relative to prognosis of patients with ICC.

Aspirin use is associated with a reduced risk of cholangiocarcinoma: a systematic review and meta-analysis

Background

Aspirin has been revealed to probably decrease the risk of cholangiocarcinoma (CCC), which, nevertheless, is of controversy. To this end, a systematic review and meta-analysis was performed to investigate the above-described association.

Methods

We thoroughly searched PubMed, EMBASE, and ISI Web of Science for relevant studies published prior to October 2017, followed by random-effects model for calculation of pooled ORs and corresponding 95% CIs. Additionally, subgroup and sensitivity analyses were carried out to confirm whether the outcomes were stable.

Results

Nine articles, consisting of 12,535 CCC patients and 92,97,450 healthy controls, were enrolled in this study. We demonstrated a significantly decreased risk of CCC in those using aspirin, with studies being heterogeneous (OR=0.69; CI=0.43–0.94; I2=97.4%). Moreover, this relationship was detected only in case-control studies (OR=0.65; 95% CI=0.38–0.93), rather than cohort studies (OR=0.94; 95% CI=0.70–1.27). Besides, in separated analysis of intrahepatic CCC and extrahepatic CCC, aspirin was more strongly correlated with a declined risk of intrahepatic CCC (OR=0.33, 95% CI=0.26–0.39; I2=93.6%) than the risk of extrahepatic CCC (OR=0.56, 95% CI=0.41–0.73; I2=0%).

Conclusion

Collectively, the aspirin administration was correlated with a significant 31% decreased risk of CCC, particularly in the intrahepatic CCC.

Interactive role of diabetes mellitus and female sex in the risk of cholangiocarcinoma: A population-based nested case-control study

Diabetes mellitus (DM) has been associated with an increased risk of extrahepatic cholangiocarcinoma (ECC) and intrahepatic cholangiocarcinoma (ICC). However, the role of DM in a population with a lower incidence of ECC remains unclear. We investigated the role of DM and other risk factors for ECC and ICC by conducting a population-based, nested, case–control study in Taiwan, a region with a lower incidence but a higher proportion of ICC. We identified patients who received a diagnosis of cholangiocarcinoma (CC) from the Taiwan Cancer Registry between 2003 and 2009. A total of 6,093 CC cases (ICC: 4,695; ECC: 1,396) and 60,906 matched controls were included. Compared with the controls, the patients with ICC and ECC were more likely to have DM, with an adjusted OR of 1.22 [95% confidence interval (CI): 1.07–1.39] and 1.48 (95% CI: 1.18–1.85), respectively. DM was associated with an increased risk of CC in the women and patients without a history of biliary tract diseases. Moreover, compared with the controls, DM was not associated with an increased risk of ECC in the patients who received cholecystectomy. These findings strongly support the positive association between DM and the increased risk of both ICC and ECC; however, this association was not observed in the patients who received cholecystectomy.

The association between BMI and gallbladder cancer risk: a meta-analysis

Obesity is a known cause of gallstone formation and gallstones increases the risk of gallbladder cancer (GBC), but the relation of body mass index (BMI) to GBC remains incompletely understood. To help elucidate the role of obesity in GBC, we performed a meta-analysis of the relationship between BMI and GBC risk. PUBMED and EMBASE databases were searched up to April 17, 2016. Fifteen articles with 5902 cases were identified. Random-effects models and dose-response meta-analyses were used to pool study results. Compared to normal weight, the pooled relative risks (RRs) and the corresponding 95% confidence intervals (CI) of GBC for overweight and obesity is 1.10 (0.98-1.23) and 1.58 (1.43-1.75) respectively. The RRs and 95% CI of overweight and obesity in man are 0.98 (0.90-1.08) and 1.43 (1.19-1.71), while the corresponding RRs in woman are 1.29 (1.08-1.55) and 1.68 (1.41-2.00) when compared to normal weight. A nonlinear dose-response relationship between BMI and risk of GBC was found (P=0.001), and the risk increased by 4% for each 1 kg/m2 increment in BMI. When adjusted for sex, at the point of BMI=25 kg/m2, the RRs (95% CIs) for women and men were 1.13 (1.01-1.25) and 0.98 (0.90-1.07) respectively. The corresponding RRs (95%CIs) at the point of BMI=30 kg/m2 were 1.56(1.39-1.75) vs. 1.24(1.06-1.44). These results suggest that association of obesity and risk of GBC is stronger in woman. Furthermore, overweight is only associated with GBC in woman. A even stricter weight control might be necessary for woman to prevent GBC.

Smoking and risk of cholangiocarcinoma: a systematic review and meta-analysis

Previous studies evaluating the association between smoking and risk of cholangiocarcinoma (CCA) have yielded controversial results. We conducted a meta-analysis to evaluate the association based on available evidence. We searched the databases of Embase, PubMed and Cochrane Central Register of Controlled Trials from inception to April 11, 2017. Studies that investigated the association between smoking and risk of CCA were included. Pooled odds ratio (OR) estimates and 95% confidence intervals (CIs) were calculated using either a random-effects or a fixed-effects model. A total of 22 studies involving 324,333 participants were identified. The summary OR of CCA was 1.31 (95% CI, 1.15 to 1.51) for smokers versus nonsmokers. The increased risk was independent of diabetes mellitus, bilious tract stone disease, and liver cirrhosis. Smokers also had increased risk of intrahepatic CCA (12 studies; OR, 1.31; 95% CI, 1.06 to 1.63) and extrahepatic CCA (12 studies; OR, 1.32; 95% CI, 1.10 to 1.59) compared with nonsmokers. The results of our meta-analysis support the hypothesis that there is a moderate association between cigarette smoking and risk of CCA.

Healthcare utilization and costs associated with cholangiocarcinoma

BACKGROUND AND AIMS

Cholangiocarcinoma is a rare but devastating malignancy associated with a poor prognosis and a high mortality rate. With the recent advances in detection and treatment, it is unclear if the incidence and outcomes of cholangiocarcinoma are improving in the United States. The aim of this study was to evaluate the trends in the incidence, costs and mortality rates of cholangiocarcinoma- related hospital admissions in the USA.

METHODS

We utilized the National Inpatient Sample Database (NIS) from 1997-2012 for all patients in whom cholangiocarcinoma (ICD-9 code 155.1, 156) was the principal discharge diagnosis. The temporal trends in the number of hospital admissions, length of stay and, hospitalization costs along with mortality rates over the study period were determined by using regression analysis for trends.

RESULTS

There was a significant increase in the number of hospital admissions for cholangiocarcinoma as the principal diagnosis from 1997 to 2012 (10 357 vs 11 970, P<0.001). The mean length of stay for cholangiocarcinoma decreased by 17 % between 1997 and 2012 from 9.5 days to 7.9 days (P<0.001). However, during the same period, the mean hospital charges per patient (adjusted for inflation) increased 113.25% from $36 460 in 1997 to $77 753 in 2012. The in-hospital mortality rate decreased from 9.3% in 1997 to 6.4% in 2012 (P<0.001).

CONCLUSIONS

There was a significant increase in the number of hospital admissions and associated costs from cholangiocarcinoma in the USA between 1997 and 2012. However, this was accompanied by a decrease in the inpatient mortality rates from cholangiocarcinoma.

Nicotine Promotes Cholangiocarcinoma Growth in Xenograft Mice

Nicotine, the main addictive substance in tobacco, is known to play a role in the development and/or progression of a number of malignant tumors. However, nicotine's involvement in the pathogenesis of cholangiocarcinoma is controversial. Therefore, we studied the effects of nicotine on the growth of cholangiocarcinoma cells in vitro and the progression of cholangiocarcinoma in a mouse xenograft model. The predominant subunit responsible for nicotine-mediated proliferation in normal and cancer cells, the α7 nicotinic acetylcholine receptor (α7-nAChR), was more highly expressed in human cholangiocarcinoma cell lines compared with normal human cholangiocytes. Nicotine also stimulated the proliferation of cholangiocarcinoma cell lines and promoted α7-nAChR-dependent activation of proliferation and phosphorylation of extracellular-regulated kinase in Mz-ChA-1 cells. In addition, nicotine and PNU282987 (α7-nAChR agonist) accelerated the growth of the cholangiocarcinoma tumors in our xenograft mouse model and increased fibrosis, proliferation of the tumor cells, and phosphorylation of extracellular-regulated kinase activation. Finally, α7-nAChR was expressed at significantly higher levels in human cholangiocarcinoma compared with normal human control liver samples. Taken together, results of this study suggest that nicotine acts through α7-nAChR and plays a novel role in the pathogenesis of cholangiocarcinoma. Furthermore, nicotine may act as a mitogen in cholestatic liver disease processes, thereby facilitating malignant transformation.

A review of the impact of obesity on common gastrointestinal malignancies

Obesity is a global pandemic and is a well-recognized risk factor for various gastrointestinal diseases. The prevalence of obesity is increasing across all age groups. There is an emergent need for focused guidelines aimed at reducing the incidence, prevalence, and associated risks of obesity. The impact of obesity on gastrointestinal cancers being multifactorial adversely influences the associated risk, disease course, prognosis, and overall survival. We have summarized the current literature highlighting the association between obesity and common gastrointestinal cancers, with specific focus on esophageal adenocarcinoma, colon cancer, hepatocellular cancer, cholangiocarcinoma, and pancreatic malignancies.

Epidemiology and Risk Factors of Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is the second most common primary liver cancer, being characterized by its late diagnosis and fatal outcome. Recent epidemiological reports indicate an increasing worldwide incidence of intrahepatic CCA but a decreasing incidence of extrahepatic CCA.

METHODS

In this review, we present an overview of the incidence and epidemiology of CCA and possible strategies for screening and surveillance.

RESULTS

Efficient strategies for the screening and surveillance of CCA have not been established so far. The vast majority of CCA occur sporadically without any apparent cause; however, several risk factors such as liver flukes, chronic biliary and liver diseases, and lifestyle-related aspects causing chronic inflammation and cholestasis in the liver have been linked to the development of CCA. These risk factors likely contribute to the increased incidence observed in some countries and also explain the wide geographical differences in the incidence of CCA.

CONCLUSION

Several risk factors for CCA have been identified. Given the dismal prognosis of advanced CCA, regular surveillance examinations with a combination of ultrasonography and laboratory tests appear to be useful in patients at risk and need to be explored in prospective trials.

Aspirin use and the risk of cholangiocarcinoma

Whether aspirin use is protective against cholangiocarcinoma (CCA) remains unclear. We determined the association between aspirin use and other risk factors for each CCA subtype individually. In a hospital-based case-control study, 2395 CCA cases (1169 intrahepatic, 995 perihilar, and 231 distal) seen at the Mayo Clinic, Rochester, MN, from 2000 through 2014 were enrolled. Controls selected from the Mayo Clinic Biobank were matched two to one with cases by age, sex, race, and residence (n = 4769). Associations between aspirin use, other risk factors, and CCA risk were determined. Aspirin was used by 591 (24.7%) CCA cases and 2129 (44.6%) controls. There was a significant inverse association of aspirin use with all CCA subtypes, with adjusted odds ratios (AORs) of 0.35 (95% confidence interval [CI], 0.29-0.42), 0.34 (95% CI 0.27-0.42), and 0.29 (95% CI 0.19-0.44) for intrahepatic, perihilar, and distal CCA, respectively (P < 0.001 for all). Primary sclerosing cholangitis was more strongly associated with perihilar (AOR = 453, 95% CI 104-999) than intrahepatic (AOR = 93.4, 95% CI 27.1-322) or distal (AOR = 34.0, 95% CI 3.6-323) CCA, whereas diabetes was more associated with distal (AOR = 4.2, 95% CI 2.5-7.0) than perihilar (AOR = 2.9, 95% CI 2.2-3.8) or intrahepatic (AOR = 2.5, 95% CI 2.0-3.2) CCA. Cirrhosis not related to primary sclerosing cholangitis was associated with both intrahepatic and perihilar CCA, with similar AORs of 14. Isolated inflammatory bowel disease without primary sclerosing cholangitis was not associated with any CCA subtype.

CONCLUSIONS

Aspirin use was significantly associated with a 2.7-fold to 3.6-fold decreased risk for the three CCA subtypes; our study demonstrates that individual risk factors confer risk of different CCA subtypes to different extents. (Hepatology 2016;64:785-796).

Overweight, obesity and the risk of gallbladder and extrahepatic bile duct cancers: A meta-analysis of observational studies

OBJECTIVE

Epidemiological studies have repeatedly investigated the association between excess body weight and the risk of biliary tract cancer with inconsistent results. The objective of this study was to quantitatively assess the associations between overweight and obesity and the risk of biliary tract cancer.

METHODS

A comprehensive search of PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases up to August 2015 was conducted, and the reference lists of retrieved articles for additional relevant studies were manually searched.

RESULTS

Fourteen prospective cohort studies and 15 case-control studies were included in this meta-analysis. These studies included 11,448,397 participants (6,733 patients with gallbladder cancer [GBC] and 5,798 patients with extrahepatic bile duct cancer [EBDC]) with follow-up durations ranging from 5 to 23 years. Among overweight adults, the pooled RR was 1.17 (95% CI, 1.07-1.28) for GBC and 1.26 (95% CI, 1.14-1.39) for EBDC, and among people with obesity, the pooled RR was 1.62 (95% CI, 1.49-1.75) for GBC and 1.48 (95% CI, 1.21-1.81) for EBDC. Visual inspection of the funnel plots and the Begg's and the Egger's tests did not show enough evidence of publication bias.

CONCLUSIONS

Integrated evidence from this meta-analysis suggests that excess body weight is associated with a significantly increased risk of GBC and EBDC.

Expert consensus document: Cholangiocarcinoma: current knowledge and future perspectives consensus statement from the European Network for the Study of Cholangiocarcinoma (ENS-CCA)

Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies with features of biliary tract differentiation. CCA is the second most common primary liver tumour and the incidence is increasing worldwide. CCA has high mortality owing to its aggressiveness, late diagnosis and refractory nature. In May 2015, the "European Network for the Study of Cholangiocarcinoma" (ENS-CCA: www.enscca.org or www.cholangiocarcinoma.eu) was created to promote and boost international research collaboration on the study of CCA at basic, translational and clinical level. In this Consensus Statement, we aim to provide valuable information on classifications, pathological features, risk factors, cells of origin, genetic and epigenetic modifications and current therapies available for this cancer. Moreover, future directions on basic and clinical investigations and plans for the ENS-CCA are highlighted.

Type 2 diabetes mellitus and risk of gallbladder cancer: a systematic review and meta-analysis of observational studies

AIMS

Increasing evidence suggests that a history of type 2 diabetes mellitus (type 2 DM) may be involved in the development of various sites of cancer. However, the association with risk of gallbladder cancer remains unclear.

METHODS

We identified studies by a literature search of MEDLINE and EMBASE through 31 August 2014 and by searching the reference lists of pertinent articles. All data were independently extracted by two investigators using a standardized data abstraction tool. Summary relative risks (SRRs) with 95% confidence intervals (CIs) were calculated with a random effects model.

RESULTS

A total of 20 studies (eight case-control studies and 12 cohort studies) were included in this meta-analysis. Analysis of these 20 studies found that compared with non-diabetic individuals, diabetic individuals had an increased risk of gallbladder cancer (SRR = 1.56, 95% CI: 1.36-1.79). There was evidence of moderate heterogeneity among these studies (p = 0.010 and I(2)  = 43.5%). This increased risk relationship is independent of smoking, body mass index and a history of gallstones. However, whether or not controlled for, alcohol use may be one of the potential confounders that significantly affect the association between type 2 DM and the risk of gallbladder cancer. Diabetic women and men had a similarly increased risk of gallbladder cancer associated with type 2 DM.

CONCLUSIONS

These findings of this systematic review indicate that compared with non-diabetic individuals, both men and women with type 2 DM had an increased risk of gallbladder cancer. Copyright © 2015 John Wiley & Sons, Ltd.

Targeted Therapy in Biliary Tract Cancers

OPINION STATEMENT

A paradigm shift towards molecular-based, personalized cancer therapeutics has occurred in recent years and a number of targeted drugs have emerged. Various targeted therapies like erlotinib, trastuzumab, and cetuximab have been approved in lung, breast, and colon cancers, respectively. Numerous clinical trials involving targeted drugs in biliary tract cancers are currently in progress, though none have been approved for this disease. Biliary tract cancers are divided into separate entities both anatomically and in terms of pathogenesis but are grouped together in most trials given their rarity. Combination chemotherapy involving cisplatin and gemcitabine is the current standard of care in the metastatic setting. In this review, we will discuss the various molecular pathways implicated in biliary tract cancers and potential therapeutic targets.

Body Mass Index and Risk of Gallbladder Cancer: Systematic Review and Meta-Analysis of Observational Studies

OBJECTIVES

To provide a quantitative assessment of the association between excess body weight, interpreted as increased body mass index (BMI), and the risk of gallbladder cancer (GBC).

METHODS

We identified eligible studies in Medline and EMBASE up to 1 February 2015, and reference lists of retrieved articles. Summary relative risks with their 95% confidence intervals were calculated in a random-effects model. Subgroup analyses were performed according to study design, gender, geographic location, ascertainment of exposure and adjustment for confounders.

RESUITS

A total of 12 cohort studies and 8 case-control studies were included in the meta-analysis. Overall, compared with "normal" weight, the summary relative risks of GBC were 1.14 (95% CI, 1.04-1.25) for overweight individuals (BMI 25-30 kg/m²) and 1.56 (95% CI, 1.41-1.73) for obese individuals (BMI > 30 kg/m²). Obese women had a higher risk of GBC than men did (women: SRRs 1.67, 95% CI 1.38-2.02; men: SRRs 1.42, 95% CI 1.21-1.66), and there was significant association between overweight and GBC risk in women (SRRs 1.26, 95% CI 1.13-1.40), but not in men (SRRs 1.06, 95% CI 0.94-1.20).

CONCLUSIONS

Findings from this meta-analysis indicate that obesity is associated with an increased risk of GBC, especially in women. Overweight is associated with GBC risk only in women.

Multidisciplinary Care of Patients with Intrahepatic Cholangiocarcinoma: Updates in Management

Cholangiocarcinoma is a highly fatal primary cancer of the bile ducts which arises from malignant transformation of bile duct epithelium. While being an uncommon malignancy with an annual incidence in the United States of 5000 new cases, the incidence has been increasing over the past 30 years and comprises 3% of all gastrointestinal cancers. Cholangiocarcinoma can be classified into intrahepatic (ICC) and extrahepatic (including hilar and distal bile duct) according to its anatomic location within the biliary tree with respect to the liver. This paper reviews the management of ICC, focusing on the epidemiology, risk factors, diagnosis, and surgical and nonsurgical management.

Clinical presentation, risk factors and staging systems of cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common primary liver tumour. Intra-hepatic CCA develops within the liver parenchyma while extrahepatic CCA involves the biliary tree within the hepatoduodenal ligament. Hilar CCA are also called Klatskin tumour. The CCA incidence has increased worldwide over the last years, but there are also geographic differences, with focus in Asian countries. Known risk factors are primary sclerosing cholangitis (PSC), hepatolithiasis, Caroli's disease, hepatitis B and C infection, liver flukes, cirrhosis, diabetes, obesity, alcohol consumption and probably tobacco smoking. Patients with early CCA have only little discomfort, but can later show episodes with jaundice and other non-specific tumour symptoms. For the staging of the disease different classifications are available, which consider various factors like tumour size, location, regional lymph nodes, metastasis, vascular involvement and tumour marker.

Diabetes mellitus and the risk of cholangiocarcinoma: an updated meta-analysis

INTRODUCTION

A number of studies have shown that diabetes mellitus is implicated in susceptibility to several cancers. However, the relationship between diabetes and cholangiocarcinoma remain unclear.

AIM

To quantitatively assess the relationship between diabetes and incidence of cholangiocarcinoma in cohort and case-control studies.

MATERIAL AND METHODS

A literature search was performed for entries from 1996 to 2014 using the PubMed and EMBASE databases. Studies were included if they reported odds ratios (OR) and corresponding 95% CI of cholangiocarcinoma with respect to diabetes mellitus.

RESULTS

Twenty studies met the inclusion criteria, which included fifteen case-control studies and five cohort studies from Asia (n = 11), the United States (n = 5), and Europe (n = 4). Compared with individuals without diabetes, the pooled OR of cholangiocarcinoma was 1.74 (95% CI: 1.62-1.87, p = 0.568 for heterogeneity) for patients with diabetes, ICC (summary RR, 1.93; 95% CI: 1.65-2.25; p = 0.037 for heterogeneity), and ECC (summary RR, 1.66; 95% CI: 1.39-1.98; p = 0.001 for heterogeneity). The funnel plot revealed no evidence for publication bias concerning diabetes and the risk of CC (including ICC and ECC).

CONCLUSIONS

The findings from this meta-analysis suggest that diabetes may increase the risk of cholangiocarcinoma. This relationship needs to be confirmed by further follow-up studies.

Type II diabetes mellitus is associated with a reduced risk of cholangiocarcinoma in patients with biliary tract diseases

It has not yet been reported whether Type II diabetes mellitus (DM) is associated with an increased cholangiocarcinoma (CC) risk in patients with biliary tract diseases. We identified 123,050 patients concomitantly diagnosed with biliary tract diseases and DM between 1998 and 2010. The control cohort consisted of 122,721 individuals with biliary tract diseases but not DM. Both cohorts were followed-up until the end of 2010 to estimate the risk of CC. We also compared the risk of CC between DM and non-DM cohorts without biliary tract diseases. Overall, the incidence of CC was 21% lower among the DM patients than among the control patients (1.11 vs. 1.41 per 1,000 person-years). DM cohorts exhibited significantly reduced risks for both intrahepatic and extrahepatic CC. A multivariable Cox proportional hazards regression model was used, and the adjusted hazard ratio (HR) of CC was 0.74 (95% confidence interval [CI], 0.66-0.82) for the DM cohort in comparison with the control cohort. The age-specific data indicated that compared with the control patients, the adjusted HRs for the DM patients were significantly lower among patients 50-64 (adjusted HR = 0.67; 95% CI = 0.55-0.82) and 65-74 years old (adjusted HR = 0.70; 95% CI, 0.59-0.84). Furthermore, DM was associated with a lower risk of CC among patients with biliary diseases, regardless of the presence of comorbidities and the status of cholecystectomy. In the patients without biliary tract diseases, DM is associated with significantly increased risk of CC (adjusted HR = 1.58; 95% CI, 1.37-1.82).

CARING (CAncer Risk and INsulin analoGues): the association of diabetes mellitus and cancer risk with focus on possible determinants - a systematic review and a meta-analysis

Background:

Patients suffering from diabetes mellitus (DM) may experience an increased risk of cancer; however, it is not certain whether this effect is due to diabetes per se.

Objective:

To examine the association between DM and cancers by a systematic review and meta-analysis according to the PRISMA guidelines.

Data Sources:

The systematic literature search includes Medline at PubMed, Embase, Cinahl, Bibliotek.dk, Cochrane library, Web of Science and SveMed+ with the search terms: “Diabetes mellitus”, “Neoplasms”, and “Risk of cancer”.

Study Eligibility Criteria:

The included studies compared the risk of cancer in diabetic patients versus non-diabetic patients. All types of observational study designs were included.

Results:

Diabetes patients were at a substantially increased risk of liver (RR=2.1), and pancreas (RR=2.2) cancer. Modestly elevated significant risks were also found for ovary (RR=1.2), breast (RR=1.1), cervix (RR=1.3), endometrial (RR=1.4), several digestive tract (RR=1.1-1.5), kidney (RR=1.4), and bladder cancer (RR=1.1). The findings were similar for men and women, and unrelated to study design. Meta-regression analyses showed limited effect modification of body mass index, and possible effect modification of age, gender, with some influence of study characteristics (population source, cancer- and diabetes ascertainment).

Limitations:

Publication bias seemed to be present. Only published data were used in the analyses.

Conclusions:

The systematic review and meta-analysis confirm the previous results of increased cancer risk in diabetes and extend this to additional cancer sites. Physicians in contact with patients with diabetes should be aware that diabetes patients are at an increased risk of cancer.

Body mass index and biliary tract disease: a systematic review and meta-analysis of prospective studies

OBJECTIVE

To evaluate the association between body mass index (BMI, kg/m(2)) and incidence of biliary tract disease.

METHODS

We performed a systematic review and a meta-analysis of prospective studies by searching the database of PubMed and EMBASE published up to December 31, 2013. Outcome of interest was disease of biliary tract system (gallbladder, extrahepatic bile duct and Ampullar of Vater). We used a random-effects model to combine the study-specific relative risks (RRs) and 95% confidence intervals (95% CIs) from 22 prospective studies. We examined whether BMI was associated with a higher risk of biliary tract disease in a combined analysis.

RESULTS

The positive association was stronger for non-cancer biliary tract disease than biliary tract cancer; combined RRs (95% CIs) comparing the top with bottom categories were 1.40 (1.15-1.65) for biliary tract cancer and 2.75 (2.35-3.15) for non-cancer biliary tract disease (P for difference<0.001). For non-cancer biliary tract disease, combined RRs (95% CIs) comparing the top with bottom categories were 3.21 (2.48-3.93) for women and 2.01 (1.66-2.37) for men (P for difference=0.04).

CONCLUSION

Obesity is associated with higher risks of biliary tract cancer and, to a greater extent, non-cancer biliary tract disease.

Aspirin may prevent cholangiocarcinoma: a case-control study from the United kingdom

BACKGROUND

The proliferation of cholangiocarcinoma cells is suppressed in cell culture by nonsteroidal antiinflammatory drugs (NSAIDs) through the inhibition of cyclo-oxygenase-2 enzyme and also by statins which decrease the production of mediators of the cell cycle.

AIMS

To investigate whether there is an inverse association between NSAIDs, including aspirin, and the development of cholangiocarcinoma and, for the first time in a Western population, between statin use and the development of cholangiocarcinoma.

METHODS

This epidemiological study had a case-control design in which cases of cholangiocarcinoma diagnosed in Norwich between 2004 and 2010 and in Leicester in 2007 were identified from clinical databases. Controls were patients with basal cell carcinomas treated in the respective dermatology departments. The case notes of all subjects were reviewed to confirm diagnoses and obtain information on medication use. The data were analyzed using unconditional logistic regression to calculate odds ratios (OR) with 95 % confidence intervals (CI).

RESULTS

In total, 81 cases of cholangiocarcinoma and 275 controls were identified. For all cases there was radiological evidence of cancer and 86 % of the cases involved the extrahepatic biliary system. Aspirin use was inversely associated with the development of cholangiocarcinoma (OR 0.45, 95 % CI 0.22-0.92), but there were no significant associations between the development of cholangiocarcinoma and NSAIDs (OR 0.39; 95 % CI 0.11-1.42) or statins (OR 0.58; 95 % CI 0.28-1.19).

CONCLUSIONS

The epidemiological data from this study support the biological evidence for aspirin having a protective effect against the development of cholangiocarcinoma. Aspirin use should be measured in future etiological studies and assessed as a chemoprevention agent in those at high risk of developing this type of cancer.

Medical risk factors associated with cholangiocarcinoma in Taiwan: a population-based case-control study

BACKGROUND

Cholangiocarcinoma, including intra- and extrahepatic cholangiocarcinoma, is a rare but highly lethal cancer. Despite effort in finding the risk factors of cholangiocarcinoma, the causes of most cholangiocarcinoma remain unknown. This study utilized a population-based case-control design using data from the National Health Insurance Research Database (NHIRD) of Taiwan to assess the medical conditions associated with cholangiocarcinoma.

METHODS

5,157 incident cases of cholangiocarcinoma diagnosed during 2004 to 2008 and 20,628 controls matched to the cases on sex, age, and time of diagnosis (reference date for the controls) were identified from the NHIRD. Medical risk factors were ascertained from the NHIRD for each individual. Conditional logistic regression was performed to evaluate the association between cholangiocarcinoma and each medical risk factor.

RESULTS

The results showed that factors associated with an increased risk of cholangiocarcinoma included cholangitis, cholelithiasis, cholecystitis, cirrhosis of liver, alcoholic liver disease, chronic non-alcoholic liver disease, hepatitis B, hepatitis C, diabetes, chronic pancreatitis, inflammatory bowel disease, and peptic ulcer. In addition, sex and age differences were observed.

CONCLUSIONS

This study confirms the association between cholangiocarcinoma and several less established risk factors, including diabetes, inflammatory bowel disease, hepatitis B, hepatitis C, and peptic ulcer (proxy for the presence of Helicobacter Pylori). Future studies should focus on finding additional environmental and genetic causes of cholangiocarcinoma.

Does diabetes mellitus with or without gallstones increase the risk of gallbladder cancer? Results from a population-based cohort study

BACKGROUND

Previous studies have suggested that diabetes mellitus (DM) is a risk factor for gallbladder cancer; however, it remains unclear whether DM with or without gallstones increases the risk of gallbladder cancer. The aim of this study was to evaluate the risk factors for gallbladder cancer, including sex, hypertension, hyperlipidemia, gallstones, and DM.

METHODS

The study cohort consisted of 214,179 subjects newly diagnosed with diabetes (cases) collected from the claims data of the Health Insurance Program of Taiwan from 2000 to 2001 who were retrospectively enrolled. The control group consisted of 206,860 subjects without diabetes, matched with the cases for sex, age, and index year. The subjects were followed up until the end of 2008. The effects of the risk factors on the incidence of gallbladder cancer were evaluated with Cox's proportional hazard regression models.

RESULTS

The risk of gallbladder cancer was higher in the DM group than in the non-DM group, with a hazard ratio (HR) of 1.53 [95 % confidence interval (CI) 1.22-1.90]. Gallstones were also a risk factor for gallbladder cancer, with an HR of 2.52 (95 % CI 1.11-5.73). DM and gallstones were synergistic risk factors for gallbladder cancer (p < 0.0001), with an HR of 5.37 (95 % CI 3.17-9.10) for subjects with both diseases in relation to those with neither of these conditions.

CONCLUSIONS

In the present long-term cohort study, DM with or without gallstones increased the risk of gallbladder cancer. Gallstones were independently related to gallbladder cancer, and DM and gallstones were synergistic risk factors for gallbladder cancer.

The effect of smoking on the risk of gallbladder cancer: a meta-analysis of observational studies

BACKGROUND

Cigarette smoking has been shown to cause many nonpulmonary cancers, including those of liver, pancreas and bladder. However, results of epidemiologic studies examining the association between smoking and gallbladder cancer (GBC) have been mixed. To clarify the association of cigarette smoking and GBC, we performed a meta-analysis of observational studies.

METHODS

A literature search was performed using Medline (from 1 January 1966) and Embase (from 1 January 1974), through 31 January 2012, and by manually searching the reference lists of pertinent articles. Summary relative risks (SRRs) with corresponding 95% confidence intervals (CIs) were calculated with a random-effects model.

RESULTS

A total of 11 articles (10 case-control and one prospective cohort studies) were used in this meta-analysis, which is based on a total of 1178 GBC cases. Analysis of 11 studies found that smokers had an increased risk of GBC development, compared with nonsmokers (SRRs 1.45, 95% CIs, 1.11-1.89). There was moderate heterogeneity among studies (Q=18.15, P=0.052, I2 =44.9%). These increased risks were independent of alcohol use and a history of gallstones. No significant publication bias was found.

CONCLUSION

Although the current evidence supports a positive link between cigarette smoking and risk of gallbladder cancer, additional population-based studies, particularly cohort studies, are needed before definitive conclusions can be drawn.