Risk factors for intrahepatic and extrahepatic cholangiocarcinoma: a case-control study in China

The value of contrast-enhanced magnetic resonance imaging for diagnosis of extrahepatic cholangiocarcinoma

Rationale and objectives

To establish a diagnostic model based on contrast-enhanced magnetic resonance imaging (MRI) and clinical characteristics for diagnosing extrahepatic cholangiocarcinoma (eCCA).

Materials and methods

From April 2014 to September 2021, consecutive patients with extrahepatic bile duct lesions who underwent contrast-enhanced MRI within 1 month before pathological examination were retrospectively enrolled. Two radiologists blinded to clinicopathological information independently evaluated MR images. Univariable and multivariable logistic regression analyses were performed to identify significant clinicoradiological features associated with eCCA, which were subsequently incorporated into a diagnostic model. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve.

Results

A total of 182 patients (mean age, 60.8 ± 10.0 years, 117 men) were included, 144 (79 %) of whom had pathologically confirmed eCCA. Diffusion restriction (odds ratio [OR], 8.32; 95 % confidence interval [CI]: 2.88, 25.82; P < 0.001), indistinct outer margin (OR, 4.01; 95 % CI: 1.40, 11.84; P = 0.010), cholelithiasis (OR, 0.34; 95 % CI: 0.12, 1.00; P = 0.049), serum ln(carbohydrate antigen 125) (OR, 4.95; 95 % CI: 1.61, 18.55; P = 0.010), and serum ln(direct bilirubin) (OR, 1.82; 95 % CI: 1.29, 2.63; P < 0.001) were independently associated with eCCA. Incorporating the above 5 variables, a diagnostic model achieved an AUC of 0.912 (95 % CI: 0.859, 0.965), with well-fitted calibration curve (P = 0.815) and good clinical utility. Additionally, the sensitivity, specificity and accuracy of the model were 83.33 %, 86.84 %, and 84.07 %, respectively.

Conclusion

The proposed model integrating two MRI features (i.e., indistinct outer margin and diffusion restriction) and three clinical characteristics (i.e., cholelithiasis, lnCA125 and lnDBIL) enabled accurate diagnosis of eCCA. This tool holds the potential to facilitate an early diagnosis and thereby allow timely treatment interventions and improved clinical outcomes for patients with eCCA.

Association between Dietary Anthocyanidins and Biliary Cancer Risk in 98,458 Participants: Results from a Prospective Study

BACKGROUND

Previous studies have suggested anthocyanidins or anthocyanidin-rich foods and extracts exhibit protective effects against various cancers. However, the relationship between dietary anthocyanidins and the risk of biliary cancer remains uncertain.

METHODS

This study used data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial to investigate the relationship between total anthocyanidins intake and biliary cancer incidence. Cox regression analysis was conducted to estimate HRs and corresponding 95% confidence intervals (CI) for the incidence of biliary cancer, with adjustments made for confounding factors. A restricted cubic spline model was employed to examine the dose-response relationship. In addition, subgroup and sensitivity analyses were conducted to evaluate potential interactions and test the model's robustness.

RESULTS

During 8.9 years and 872,645.3 person-years of follow-up, 95 cases of biliary cancer were observed. The incidence rate of biliary cancer in this study was 11 cases per 100,000 person-years. Using the fully adjusted Cox regression model, the inverse association was observed between total anthocyanidins intake and the risk of biliary cancer (HR Q4 vs..Q1: 0.52; 95% CI: 0.29-0.91; Ptrend = 0.043). This association remained significant in sensitivity analyses. A linear dose-response relationship (Pnonlinearity = 0.118) and potential interaction with drinking status (Pinteraction = 0.033) were identified.

CONCLUSIONS

This study provides evidence of an inverse association between total anthocyanidins intake and biliary cancer incidence.

IMPACT

Our study found a total anthocyanidin-rich diet was associated with a reduced risk of biliary cancer in Americans ages 55 to 74 years.

Cholecystectomy and risk of liver disease: a systematic review and meta-analysis of 27 million individuals

BACKGROUND

There is still a lack of knowledge on the association between cholecystectomy and liver disease. This study was conducted to summarize the available evidence on the association of cholecystectomy with liver disease and quantify the magnitude of the risk of liver disease after cholecystectomy.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library were searched systematically from database inception to January 2023 to identify eligible studies that evaluated the association between cholecystectomy and the risk of liver disease. Meta-analysis was conducted to obtain a summary odds ratio (OR) and 95% confidence interval (CI) using a random-effects model.

RESULTS

We identified 20 studies with a total of 27 320 709 individuals and 282 670 liver disease cases. Cholecystectomy was associated with an increased risk of liver disease (OR: 1.63, 95% CI: 1.34-1.98). In particular, cholecystectomy was found to be significantly associated with a 54% increased risk of nonalcoholic fatty liver disease (OR: 1.54, 95% CI: 1.18-2.01), a 173% increased risk of cirrhosis (OR: 2.73, 95% CI: 1.81-4.12), and a 46% increased risk of primary liver cancer (OR: 1.46, 95% CI: 1.18-1.82).

CONCLUSIONS

There is an association between cholecystectomy and the risk of liver disease. Our results suggest that strict surgical indications should be implemented to reduce unnecessary cholecystectomy. Additionally, the routine assessment of liver disease is necessary for patients with a history of cholecystectomy. More prospective large-sample studies are required for better estimates of the risk.

Long-term outcomes of anatomic vs. non-anatomic resection in intrahepatic cholangiocarcinoma with hepatolithiasis: A multicenter retrospective study

Background

The benefits of anatomic resection (AR) vs. non-anatomic resection (NAR) in patients with primary intrahepatic cholangiocarcinoma (ICC) with hepatolithiasis (HICC) are unclear. This study aimed to compare the long-term outcomes of AR vs. NAR in patients with HICC.

Methods

A total of 147 consecutive patients with HICC who underwent R0 hepatectomy were included. Overall survival (OS) and recurrence-free survival (RFS) following AR vs. NARs were compared using a 1:1 propensity score matching (PSM) analysis. A subgroup analysis was also conducted according to whether there are lymph node metastases (LNM).

Results

In a multivariate analysis, CA 19-9 (>39 U/L), microvascular invasion, LNM, and NAR were independent risk factors for poor RFS and OS rates, whereas multiple tumors were independent risk factors for OS. AR had better 1-, 3-, and 5-year RFS and OS rates than NAR (OS: 78.7, 58.9, and 28.5%, respectively, vs. 61.2, 25.4, and 8.8%, respectively; RFS: 59.5, 36.5, and 20.5%, respectively, vs. 38.2, 12.1, and 6.9%, respectively). After PSM, 100 patients were enrolled. The NAR group also had significantly poorer OS and RFS (OS: 0.016; RFS: p = 0.010) than the AR group. The subgroup analysis demonstrated that in HICC without LNM, OS and RFS were significantly poorer in the NAR group than the AR group, while no significant differences were observed in HICC with LNM before or after PSM.

Conclusion

Anatomic resection was associated with better long-term survival outcomes than NAR in patients with HICC, except for patients with LNM.

Hepatitis B and C virus infections and the risk of biliary tract cancers: a meta-analysis of observational studies

Background

Both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are important risk factors for hepatocellular carcinoma. However, their effect on other hepatobiliary cancers, such as biliary tract cancers (BTCs), is not well established. We aimed to investigate associations between HBV or HCV infection and BTCs risk by conducting a systematic review and meta-analysis.

Methods

We searched PubMed to identify all relevant articles published before June 9, 2021. Meta-analysis was performed to calculate pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs). The meta-analysis was evaluated by heterogeneity testing, sensitivity analyses, and publication bias assessment.

Results

In total, 48 articles involving 69,723 cases and 4,047,574 controls were obtained to calculate the associations between HBV or HCV infection and the risk of BTCs. We found that both HBV and HCV infections were associated with the risk of BTCs, with pooled ORs of 2.16 (95% CI 1.73–2.69) and 2.12 (95% CI 1.62–2.77), respectively. Subgroup analyses by ethnicity suggested that HBV infection could increase the risk of BTCs in both Asian (OR = 2.29, 95% CI 1.76–2.97) and Caucasian (OR = 1.80, 95% CI 1.18–2.75) populations. In addition, HCV infection resulted in a higher increased risk of BTCs in Caucasian populations than in Asian populations (OR = 3.93 vs. 1.51, P = 0.014). In particular, significantly increased risks of intrahepatic cholangiocarcinoma (ICC) were identified in individuals with HBV (OR = 3.96, 95% CI 3.05–5.15) or HCV infection (OR = 2.90, 95% CI 2.07–4.08).

Conclusions

This study suggests that both HBV and HCV infections are risk factors for BTCs, particularly ICC, highlighting the necessity of cancer screening for BTCs in patients with either HBV or HCV infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13027-022-00457-9.

Associations between ultrasound screening findings and cholangiocarcinoma diagnosis in an at-risk population

The rate of cholangiocarcinoma (CCA) is increasing every year, especially in northeastern Thailand. Screening for CCA using ultrasonography (US) is the fastest technique to identify patients in early stage of CCA development. Currently, few studies have examined patterns of hepatobiliary abnormalities identified using US, which can be indicative of CCA. We aim to evaluate the rate of CCA and its relations to history of US findings. Our study included participants who underwent US and pathological diagnosis of CCA from the Cholangiocarcinoma Screening and Care Program, Northeast Thailand between 2013 and 2020. Data on histological findings were based on the standard protocol of the tertiary hospital at Khon Kaen University. CCA data is categorized into two groups (yes/no) to find the relationship with history of US findings. The adjusted odds ratio (AOR) and their 95% confidence intervals (CI) were used to evaluate the relationship obtained by multiple logistic regression. Of 1880 subjects who underwent US and a pathological diagnosis of CCA, the overall rate of CCA was 35.74%. CCA rate among those with liver mass (LM) was 54.85% and with dilated bile duct (DBD) was 62.01%. The relationship between DBD and CCA was highly significant (AOR = 3.46; 95% CI 2.74–4.36) followed by LM (AOR = 2.28; 95% CI 1.81–2.86) P value < 0.001. Our study reveals that US findings history have a strong association with CCA, especially in people diagnosed with DBD and LM. Therefore, these abnormalities can be indicators for suspected CCA diagnosis through US.

A prospective cohort study of cigarette smoking, alcohol drinking and liver cancer incidence in Chinese men

OBJECTIVES

Population-based prospective studies on the associations of cigarette smoking, alcohol drinking, and primary liver cancer remain limited in Mainland China. Our study was designed to evaluate such relationships in middle-aged Chinese men.

METHODS

Self-reported habits of cigarette smoking and alcohol drinking were obtained from all cohort members at the baseline survey. The outcomes were identified through in-person follow-up and annual record linkage to multiple statistics of vital and cancer registration. Age-adjusted and multivariable-adjusted hazard ratio (HR) and their corresponding 95% confidence interval (CI) were estimated utilizing the Cox regression model.

RESULTS

After a median follow-up of 12.31 years, 329 cases of incident primary liver cancer occurred among 45 266 male participants. Compared with never smoker, former smoker was positively associated with liver cancer risk, with a multivariable-adjusted HR of 1.42 (95% CI 1.02-1.98). Individuals who had smoked for more than 40 years had a 49% increased risk of liver cancer (HR≥40 years  1.49, 95% CI 1.04-2.14). The association of alcohol drinking with liver cancer showed no statistical significance.

CONCLUSIONS

Our study provided evidence that cigarette smoking was positively associated with an increased liver cancer risk among Chinese men. Attention to such non-viral modifiable risk factors to prevent liver cancer effectively is needed.

Postoperative survival of extrahepatic and intrahepatic cholangiocarcinoma after surgery: a population-based cohort

OBJECTIVES

The study was designed to clarify the difference between extrahepatic cholangiocarcinoma (ECC) and intrahepatic cholangiocarcinoma (ICC) in postoperative cancer-specific death.

DESIGN

Patients diagnosed with ECC and ICC after surgery, who are identified from the Surveillance, Epidemiology and End Results programme, are eligible for this retrospective cohort study.

SETTING

Survival between groups was compared using the traditional Kaplan-Meier method and the cumulative incidence function (CIF) method. Propensity score-matched (PSM) analysis was conducted to balance the differences in vital variables between groups. The HR and 95% CI for ECC relative to ICC were used to quantify the risk of death. Subgroup analysis was further used to evaluate the stability of the differences between groups.

RESULTS

The study included 876 patients with ECC and 1194 patients with ICC. Before PSM, with the Kaplan-Meier method, postoperative overall survival and cancer-specific death for ECC were worse than those for ICC. However, with the CIF method, no difference in postoperative cancer-specific death was found. After PSM, all differences in the considered traits were balanced, and 173 pairs of patients were retained. Survival analysis found that there was no difference in postoperative all-cause death (Kaplan-Meier method, p=0.186) or cancer-specific death (Kaplan-Meier and CIF methods, p=0.500 and p=0.913, respectively), which was consistent with subgroup analysis.

CONCLUSIONS

ECC and ICC showed no difference in postoperative cancer-specific death, both in the natural state and in multiple variable-matched conditions.

TRIAL REGISTRATION NUMBER

researchregistry4175.

Recurrence and prognosis in intrahepatic cholangiocarcinoma patients with different etiology after radical resection: a multi-institutional study

Objective

We aimed to evaluate the prognosis and adjuvant chemotherapy (ACT) in intrahepatic cholangiocarcinoma (ICC) patients with different etiology after radical resection.

Methods

A total of 448 patients with ICC who underwent radical resection between 2010 and 2018 at ten Chinese tertiary hospitals were analyzed in the study. These patients were divided into conventional ICC (Con-ICC, n = 261, 58.2%), hepatitis B virus ICC (HBV-ICC, n = 102, 22.8%) and hepatolithiasis (Stone-ICC, n = 85,19.0%) subtypes according to different etiology. Propensity score matching (PSM) was conducted to mitigate the baseline differences between Con-ICC and HBV-ICC, Con-ICC and Stone-ICC, HBV-ICC and Stone-ICC subtypes.

Results

Univariate and multivariate analysis showed that different etiology was a prognostic factor for overall survival and relapse-free survival, and different etiology was an independent risk factor for overall survival in ICC patients, respectively (P < 0.05). In addition, there was a statistical difference for overall survival in early recurrence patients among the three etiological subtypes (P < 0.05). After PSM, the overall survival of patients with Stone-ICC was worse than those of Con-ICC and HBV-ICC subtypes (P < 0.05), while the relapse-free survival of patients with Stone-ICC was equivalent to patients with Con-ICC and HBV-ICC (P > 0.05). In Stone-ICC patients, the median overall survival was 16.0 months and 29.7 months, and the median relapse-free survival was 9.0 months and 20.0 months for non-ACT and ACT patients, respectively (P < 0.05).

Conclusion

The prognosis of Stone-ICC patients was significantly worse than those of Con-ICC and HBV-ICC patients. Interestingly, postoperative adjuvant chemotherapy can improve the prognosis of Stone-ICC patients effectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09448-w.

Development and validation of a machine learning-based nomogram for prediction of intrahepatic cholangiocarcinoma in patients with intrahepatic lithiasis

BACKGROUND

Accurate diagnosis of intrahepatic cholangiocarcinoma (ICC) caused by intrahepatic lithiasis (IHL) is crucial for timely and effective surgical intervention. The aim of the present study was to develop a nomogram to identify ICC associated with IHL (IHL-ICC).

METHODS

The study included 2,269 patients with IHL, who received pathological diagnosis after hepatectomy or diagnostic biopsy. Machine learning algorithms including Lasso regression and random forest were used to identify important features out of the available features. Univariate and multivariate logistic regression analyses were used to reconfirm the features and develop the nomogram. The nomogram was externally validated in two independent cohorts.

RESULTS

The seven potential predictors were revealed for IHL-ICC, including age, abdominal pain, vomiting, comprehensive radiological diagnosis, alkaline phosphatase (ALK), carcinoembryonic antigen (CEA), and cancer antigen (CA) 19-9. The optimal cutoff value was 2.05 µg/L for serum CEA and 133.65 U/mL for serum CA 19-9. The accuracy of the nomogram in predicting ICC was 82.6%. The area under the curve (AUC) of nomogram in training cohort was 0.867. The AUC for the validation set was 0.881 from The Second Affiliated Hospital of Wenzhou Medical University, and 0.938 from The First Affiliated Hospital of Fujian Medical University.

CONCLUSIONS

The nomogram holds promise as a novel and accurate tool to predict IHL-ICC, which can identify lesions in IHL in time for hepatectomy or avoid unnecessary surgical resection.

Update on the association of hepatitis B with intrahepatic cholangiocarcinoma: Is there new evidence?

Intrahepatic cholangiocarcinoma (iCCA) is a subgroup of cholangiocarcinoma that accounts for about 10%-20% of the total cases. Infection with hepatitis B virus (HBV) is one of the most important predisposing factors leading to the formation of iCCA. It has been recently estimated based on abundant epidemiological data that the association between HBV infection and iCCA is strong with an odds ratio of about 4.5. The HBV-associated mechanisms that lead to iCCA are under intense investigation. The diagnosis of iCCA in the context of chronic liver disease is challenging and often requires histological confirmation to distinguish from hepatocellular carcinoma. It is currently unclear whether antiviral treatment for HBV can decrease the incidence of iCCA. In terms of management, surgical resection remains the mainstay of treatment. There is a need for effective treatment modalities beyond resection in both first- and second-line treatment. In this review, we summarize the epidemiological evidence that links the two entities, discuss the pathogenesis of HBV-associated iCCA, and present the available data on the diagnosis and management of this cancer.

Comparison of ICC patients with hepatitis B infection to those with no major risk factors for HCC

BACKGROUND

There has been renewed interest in HBV-associated ICC, because it could share a common carcinogenesis disease process with HCC. We investigated whether there is a difference in clinical outcome between ICC patients with HBV infection and those without any major risk factors for HCC.

METHODS

A total of 253 curatively resected, surgically diagnosed ICC patients were analyzed and divided into two groups according to the presence or absence of major risk factors for HCC: an HBV group (n = 45) and a non-HCC-risk (NHR) group (n = 208).

RESULTS

Lymph node metastasis was more frequently observed in the NHR group (HBV vs. NHR: 8.89% vs. 24.52%, P = 0.027). Patients in the HBV group demonstrated more favorable survival than those in the NHR group. However, this difference was not statistically significant (5-year survival rate, 54.7% vs. 42.3%, P = 0.128). Cumulative recurrence rate in the HBV group was 62.2%, which was not significantly different from 63.0% in the NHR group (P = 1.000).

CONCLUSION

This study found that while ICC patients with HBV infection showed some favorable tumor characteristics, patients' stage-specific survival and recurrence rates were not significantly different compared to those without any major risk factors for HCC.

Liver Imaging and Data System (LI-RADS) Version 2018 and Other Imaging Features in Intrahepatic Cholangiocarcinoma in Chinese Adults with vs. without Chronic Hepatitis B Viral Infection

PURPOSE

To describe liver imaging reporting and data system (LI-RADS) version 2018 and other MRI imaging features in intrahepatic mass-forming cholangiocarcinoma (iCCA) in Chinese adults with vs. without chronic hepatitis B viral (HBV) infection.

METHODS

We retrospectively enrolled 89 patients with pathologically proven iCCA after multiphase imaging performed between 2004 and 2017 at a tertiary medical center in southern China. Based on whether patients had chronic HBV, iCCA was divided into two subgroups: HBV-positive (n = 50 patients, including 9 with cirrhosis) vs. HBV-negative (n = 39 patients, including 14 with hepatolithiasis and 25 with no identifiable risk factor for iCCA; none had cirrhosis). Two independent abdominal radiologists in consensus reviewed the largest mass in each patient to assign LI-RADS v2018 features; they also scored each observation's shape and location. Imaging features were compared using chi-square or Fisher's exact tests.

RESULTS

Most iCCAs in HBV-positive (88% (44/50)) and HBV-negative (97% (38/39)) patients had at least one LR-M feature. Compared to iCCAs in HBV-negative patients, iCCAs in HBV-positive patients were more likely to have at least one major feature of HCC (46% (23/50) vs. 8% (3/39), P < 0.001) and more likely to be smooth (42% (21/50) vs. 10% (4/39), P = 0.001). Six of 50 (12%) iCCAs in HBV-positive patients and 1/39 (3%) iCCAs in HBV-negative patients had at least one major feature of HCC without any LR-M feature.

CONCLUSIONS

In this retrospective single-center study in Chinese adults, iCCAs in HBV-positive patients were more likely to resemble HCCs than iCCAs in HBV-negative patients.

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.

Analysis of bile acid profile in plasma to differentiate cholangiocarcinoma from benign biliary diseases and healthy controls

Bile acids (BAs) are currently considered as causative agents for Cholangiocarcinoma (CCA). However, the profile of circulating BAs in CCA have not been well characterized. The aim of this study was to describe the alterations of BAs metabolism in patients with CCA compared to benign biliary diseases (BBD) and healthy controls (HC), and to discover the specific BAs as biomarkers for CCA diagnosis. The concentrations of 15 BAs in plasma were measured in a total of 329 subjects, including patients with BBD, CCA, gallbladder cancer (GC), hepatocellular carcinoma (HCC), and healthy subjects, using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Binary logistic regression analysis was used to build a diagnostic model for CCA. An imbalance in the ratio of conjugated to unconjugated BAs was observed in CCA patients compared to BBD and HC groups, with higher conjugated BAs and lower unconjugated BAs. A panel of 2 BA metabolites consisting of CDCA and TCDCA showed high diagnostic performance for CCA versus BBD and CCA versus HC, with higher AUC, sensitivity and specificity than carbohydrate antigen 19-9 (CA 199), clinically employed CCA biomarker. Importantly, HCC and GC samples were also included to confirm specificity of the BA biomarkers for CCA diagnosis. In summary, specific changes in plasma concentrations of BAs may serve as diagnostic biomarkers for distinguishing CCA from BBD and HC, with higher performance than CA199.

Cholecystectomy reduces subsequent cholangiocarcinoma risk in choledocholithiasis patients undergoing endoscopic intervention

BACKGROUND

Cholangiocarcinoma is a disease with a high mortality rate. Our previous study revealed that cholelithiasis patients who undergo endoscopic sphincterotomy (ES)/endoscopic papillary balloon dilatation are at a higher risk for subsequent cholangiocarcinoma than cholelithiasis patients who undergo cholecystectomy.

AIM

To clarify the relationship between recurrent biliary events and subsequent cholangiocarcinoma risk in choledocholithiasis patients.

METHODS

From one million random cases in the Taiwan National Health Insurance Research Database 2004–2011, we selected symptomatic choledocholithiasis patients older than 18 years who were admitted from January 2005 to December 2009 (study group). Cases for a control group were defined as individuals who had never been diagnosed with cholelithiasis, matched by sex and age in a 1:3 ratio. The study group was further divided into ES/endoscopic papillary balloon dilatation, both ES/endoscopic papillary balloon dilatation and cholecystectomy, and no intervention groups.

RESULTS

We included 2096 choledocholithiasis patients without previous intervention or cholangiocarcinoma. A total of 12 (2.35%), 11 (0.74%), and 1 (1.00%) subsequent cholangiocarcinoma cases were diagnosed among 511 ES/endoscopic papillary balloon dilatation patients, 1485 patients with no intervention, and 100 ES/endoscopic papillary balloon dilatation and cholecystectomy patients, respectively. The incidence rates of recurrent biliary event were 527.79/1000 person-years and 286.69/1000 person-years in the subsequent cholangiocarcinoma and no cholangiocarcinoma group, showing a high correlation between subsequent cholangiocarcinoma risk and recurrent biliary events.

CONCLUSION

Choledocholithiasis patients who undergo further cholecystectomy after ES/endoscopic papillary balloon dilatation have decreased subsequent cholangiocarcinoma risk due to reduced recurrent biliary events.

Effect of liver fibrosis on survival in patients with intrahepatic cholangiocarcinoma: a SEER population-based study

BACKGROUND

Intrahepatic cholangiocarcinoma (iCCA) is a biliary tract malignancy with rising incidence in recent decades. While the causative role of cirrhosis in the development of iCCA is well established, the role of cirrhosis as a prognostic factor in iCCA is debatable.

MATERIALS AND METHODS

The study population consisted of 512 patients diagnosed with iCCA between 2004-2016 collected from the Surveillance, Epidemiology and End Results (SEER) database. The impact of fibrosis on overall and cancer-specific survival 12, 36 and 60 months following diagnosis, was evaluated in the entire cohort and in sub-groups stratified according to treatment approach and the American Joint Committee on Cancer (AJCC) tumor stage using a Cox proportional-hazards model.

RESULTS

After adjusting for age, sex, race, year of diagnosis, AJCC stage, and surgical treatment strategy, advanced fibrosis was associated with worse cancer-specific survival across follow up periods (HR 1.49 (1.13-1.96, p = 0.005); HR 1.44 (1.14-1.83, p = 0.002) and HR 1.45 (1.15-1.83, p = 0.002) for 12, 36 and 60 months, respectively). Similar effects were observed for overall survival. Among patients that underwent surgical resection, advanced fibrosis was associated with worse overall survival and cancer-specific survival across follow up periods. Fibrosis was associated with worse overall and cancer-specific survival in patients with a later stage (III-IV) at diagnosis but this effect was not demonstrated in early stages.

CONCLUSIONS

Patients with iCCA and advanced liver fibrosis have an increased risk of both overall and cancer-specific mortality compared to patients with earlier stages of fibrosis.

Spatial analysis of hepatobiliary abnormalities in a population at high-risk of cholangiocarcinoma in Thailand

Cholangiocarcinoma (CCA) is a serious health challenge with low survival prognosis. The liver fluke, Opisthorchis viverrini, plays a role in the aetiology of CCA, through hepatobiliary abnormalities: liver mass (LM), bile duct dilation, and periductal fibrosis (PDF). A population-based CCA screening program, the Cholangiocarcinoma Screening and Care Program, operates in Northeast Thailand. Hepatobiliary abnormalities were identified through ultrasonography. A multivariate zero-inflated, Poisson regression model measured associations between hepatobiliary abnormalities and covariates including age, sex, distance to water resource, and history of O. viverrini infection. Geographic distribution was described using Bayesian spatial analysis methods. Hepatobiliary abnormality prevalence was 38.7%; highest in males aged > 60 years (39.8%). PDF was most prevalent (20.1% of males). The Standardized Morbidity Ratio (SMR) for hepatobiliary abnormalities was highest in the lower and upper parts of the Northeast region. Hepatobiliary abnormalities specifically associated with CCA were also more common in males and those aged over 60 years and distributed along the Chi, Mun, and Songkram Rivers. Our findings demonstrated a high risk of hepatobiliary disorders in Northeast Thailand, likely associated with infection caused by O. viverrini. Screening for CCA and improvement of healthcare facilities to provide better treatment for CCA patients should be prioritized in these high-risk areas.

Identification of Cholangiocarcinoma Associated with Hepatolithiasis via the Combination of miRNA and Ultrasound

Background

Identification of cholangiocarcinoma (CCA) associated with hepatolithiasis (HL) is difficult. There is no effective method to discriminate CCA associated with HL (HL-CCA) from HL currently.

Objective

To explore the value of clinical data, ultrasonic characteristics and miRNA expression level in the identification of HL-CCA.

Methods

Thirty-one patients with HL-CCA in Huazhong University of Science and Technology Union Shenzhen Hospital were enrolled in the observation group, while 40 patients with HL alone were included in the control group. The clinical data, ultrasonic characteristics, and miRNA expression level of the two groups were recorded and analyzed to explore the potential indicators for the identification of HL-CCA.

Results

The accuracy of ultrasound in the diagnosis of HL-CCA was low (54.84%). Multivariate logistic regression analysis showed that liver abscess (P=0.021), indistinct border demarcation (P=0.015), non-homogenous echotexture (P=0.019), missed portal vein around lesion (P=0.032), miRNA-21 (P=0.018) and miRNA-221 (P=0.009) were the potential indicators for the identification of HL-CCA. The combined diagnosis based on logistic regression contained liver abscess, border demarcation, echotexture, portal vein around lesion, miRNA-21 and miRNA-221. The results showed that the accuracy of combined diagnosis identifying HL-CCA was the most accurate (AUC=0.911), which was significantly greater than the AUC of miRNA-21 or miRNA-221 individually (P<0.05), with a sensitivity and specificity of 77.42% and 97.50%, respectively.

Conclusion

Patients with HL-CCA show high incidence of hepatic abscess and elevated miRNA-21 and miRNA-221 expression level. The ultrasonic features are more likely to show indistinct border demarcation, non-homogenous echotexture, and missed portal vein around lesion. The combined diagnosis is more accurate in the identification of HL-CCA.

Preoperative Bilirubin-Adjusted Carbohydrate Antigen 19-9 as a Prognostic Factor for Extrahepatic Cholangiocarcinoma Patients at a Single Center

Purpose

The aims of our study were to investigate the prognostic impact of the rate of preoperative serum carbohydrate antigen 19-9/bilirubin (CA19-9/BR) on patients with extrahepatic bile duct cancer.

Patients and Methods

We collected clinical data from 89 patients who underwent surgery for extrahepatic cholangiocarcinoma (ECC) at Peking Union Medical College Hospital between January 2012 and December 2017. The Kaplan–Meier analysis for univariate analysis and the Cox proportional hazards models for multivariate analysis were used to determine possible independent prognostic factors.

Results

CA19-9/BR was classified as elevated compared with normal based on the upper serum normal values of CA19-9 (37 U/mL) and bilirubin (1.5 mg/dL), which gives a cut-off at 25 U/mL/mg/dL. Univariate analysis showed that the overall survival of patients with a high CA19-9/BR ratio was significantly worse compared with patients with a low CA19-9/BR ratio (Hazard Ratio [HR] 2.149; 95% Confidence Interval [95% CI] 1.027–4.495; P=0.042). Multivariate analysis revealed that a high CA19-9/BR ratio (HR 3.250; 95% CI 1.165–9.067; P=0.024), low differentiation (HR 3.551; 95% CI 1.231–10.244; P=0.019), and positive margin (HR 2.555; 95% CI 1.111–5.875; P=0.027) remained independent prognostic factors after adjusting for age at diagnosis, maximal diameters, and other possible factors.

Conclusion

The preoperative CA19-9/BR ratio is a good prognostic factor in predicting survival in ECC patients and closer follow-up is recommended in patients with a higher CA19-9/BR ratio before surgery.

Risk factors for intrahepatic and extrahepatic cholangiocarcinoma: A systematic review and meta-analysis

BACKGROUND & AIMS

Cholangiocarcinoma (CCA) carries a poor prognosis, is increasing in incidence and its causes are poorly understood. Although some risk factors are known, they vary globally and collectively account for a minority of cases. The aim of this study was to perform a comprehensive meta-analysis of risk factors for intrahepatic (iCCA) and extrahepatic cholangiocarcinoma (eCCA), from Eastern and Western world studies.

METHODS

A literature search of case-control studies was performed to identify potential risk factors for iCCA and eCCA. Pooled odds ratios (ORs) with 95% CIs and heterogeneity were calculated. Funnel plots were used to assess publication bias, and meta-regression was used to select risk factors for comparison between Eastern and Western studies.

RESULTS

A total of 13 risk factors were selected from 25 case-control studies in 7 geographically diverse countries. The strongest risk factors for both iCCA and eCCA were biliary cysts and stones, cirrhosis, hepatitis B and hepatitis C. Choledochal cysts conferred the greatest risk of both iCCA and eCCA with pooled ORs of 26.71 (95% CI 15.80-45.16) and 34.94 (24.36-50.12), respectively. No significant associations were found between hypertension and obesity for either iCCA or eCCA. Comparing Eastern and Western populations, there was a difference for the association of hepatitis B with iCCA (coefficient = -0.15195; 95% CI -0.278 to -0.025; p = 0.022).

CONCLUSION

This is the most comprehensive meta-analysis of CCA risk factors to date. Some risk factors, such as diabetes, although less strong, are increasing globally and may be contributing to rising rates of this cancer.

LAY SUMMARY

Cholangiocarcinoma (CCA) is a cancer arising in the bile ducts inside (intrahepatic CCA) and connected to the liver (extrahepatic CCA). It is a very aggressive cancer: 95% of patients die within 5 years. CCA rates are increasing globally, but the causes of CCA are poorly understood. The few risk factors that are known account for only a minority of cases. In this study, we found that the strongest risk factors for both intrahepatic and extrahepatic CCA are cysts and stones in the bile ducts, cirrhosis, and hepatitis B and C viruses. Some risk factors for CCA, such as diabetes, although less strong, are increasing globally and may be contributing to rising rates of CCA.

Prognostic Nomogram That Predicts Overall Survival of Patients with Distal Cholangiocarcinoma After Pancreatoduodenectomy

PURPOSE

We aimed to develop a nomogram for predicting the prognosis of patients with distal cholangiocarcinoma (DCC) and to compare its performance with that of the American Joint Committee on Cancer (AJCC) TNM system.

PATIENTS AND METHODS

To develop a nomogram, we collected the clinical data of 147 patients diagnosed with DCC who underwent pancreatoduodenectomy. Predictive accuracy and discriminative ability were determined using a concordance index and a calibration curve. Predictive performance was compared with that of a current staging systems for DCC.

RESULTS

Multivariate analysis revealed that jaundice, alcohol consumption, high fibrinogen, poorly differentiated tumor cells, positive lymph nodes, and positive margins were significantly associated with overall survival. These variables were incorporated into the nomogram. The concordance index of the nomogram for predicting overall survival was 0.737 (P<0.001), which is significantly higher than the concordance index values (concordance index = 0.586) acquired using the AJCC TNM system (eighth edition). The calibration curve agreed well with predicted prediction and observed overall survival.

CONCLUSION

We developed a nomogram for predicting the prognoses of patients with distal cholangiocarcinoma, which had superior practical clinical value compared with that of the AJCC TNM system.

Free episomal and integrated HBV DNA in HBsAg-negative patients with intrahepatic cholangiocarcinoma

There is evidence that chronic hepatitis B virus (HBV) infection is associated with an increased risk of intrahepatic cholangiocarcinoma (ICC) development, and it has been hypothesized an etiological role of HBV in the development of this tumor. Very little is known about occult HBV infection (OBI) in ICC. Aims of the study were to investigate the OBI prevalence and to characterize the HBV molecular status at intrahepatic level in OBI-positive cases with ICC.

Frozen liver tumor specimens from 47 HBV surface-antigen-negative patients with ICC and 41 paired non-tumor liver tissues were tested for OBI by 4 different HBV-specific nested PCR. Covalently closed circular HBV DNA (HBV cccDNA) and viral integrations were investigated in OBI-positive cases.

HBV DNA was detected in tumor and/or non-tumor specimens from 29/47 (61.7%) ICC patients. HBV cccDNA was found in tissues from 5/17 (34.5%) cases examined. HBV integration was detected in 4/10 (40%) tumor tissues tested and involved HBx and HBV-core gene sequences in 3 and 1 cases, respectively. Viral integration occurred: (a) 9,367 nucleotides upstream of the cat-eye-syndrome critical region protein-5-isoform coding sequence; (b) within the cystinosin isoform-1-precursor gene; (c) within the thromboxane-A-synthase-1 gene; (d) within the ATPase phospholipid transporting 9B gene.

Occult HBV infection is highly prevalent in patients with ICC. Both free viral genomes and integrated HBV DNA can be present in these cases. These results suggest an involvement of HBV in the carcinogenic process leading to ICC development even in cases with occult infection.

Association between periductal fibrosis and bile duct dilatation among a population at high risk of cholangiocarcinoma: a cross-sectional study of cholangiocarcinoma screening in Northeast Thailand

OBJECTIVES

To assess associations between periductal fibrosis (PDF) and bile duct dilatation (BDD) in ultrasonography (US) screening of population at risk of cholangiocarcinoma (CCA) due to residence in an endemic area for Opisthorchis viverrini. CCA survival rates are low, and early identification of risk factors is essential. BDD is one symptom that can identify patients at risk of CCA. Detection of PDF by US can also identify at-risk patients, at an earlier stage of CCA development. Identification of association between PDF and BDD will inform screening practices for CCA risk, by increasing the viability of PDF screening for CCA risk.

SETTING

Nine tertiary care hospitals in Northeast Thailand.

DESIGN

Cross-sectional study.

PARTICIPANTS

Study subjects in the Cholangiocarcinoma Screening and Care Program (CASCAP) in Northeast Thailand. CASCAP inclusion criteria are all residents of Northeast Thailand aged ≥40 years. Participants are recruited through CCA screening centres and through primary healthcare units. So far, 394 026 have been enrolled.

METHODS

PDF and BDD were identified through US. PDF was categorised into three groups, PDF1, 2 and 3, depending on their high echo locality in the peripheral, segmental and main bile duct, respectively. Associations between PDF and BDD were determined by adjusted OR and 95% CI using multiple logistic regression.

RESULTS

BDD was found in 6.6% of PDF3, 1.7% of PDF2 and 1.4% of PDF1 cases. Among PDF cases, especially in PDF3, BDD was found in men more than in women (8.9% and 4.6%, respectively). Compared with non-PDF, the association between PDF3 and BDD was highly significant (adjusted OR=5.74, 95% CI 4.57 to 7.21, p<0.001).

CONCLUSIONS

Our findings reveal that there is a relationship between PDF and BDD, which is associated with CCA. Therefore, PDF can also be an indicator for suspected CCA diagnosis through US.

Repeated praziquantel treatment and Opisthorchis viverrini infection: a population-based cross-sectional study in northeast Thailand

Background

Opisthorchis viverrini infection is highly prevalent in northeast Thailand. This liver fluke is classified as a carcinogen due to its causal links with cholangiocarcinoma (CCA) development. Although treatment with praziquantel (PZQ) effectively cures O. viverrini infection, the prevalence remains high due to the traditional consumption of raw fish. Therefore, re-infection is common in the endemic community, leading to severe hepato-biliary morbidities including the fatal CCA. In this study, we evaluate the association between the frequency of previous PZQ treatment and current O. viverrini infections among Thai adults living in the endemic area of northeast Thailand.

Methods

This study includes all participants who were screened for O. viverrini infection in the Cholangiocarcinoma Screening and Care Program (CASCAP), northeast Thailand. History of PZQ treatment was recorded using a health questionnaire. O. viverrini infections were diagnosed using urine antigen detection. Associations between PZQ and O. viverrini were determined by adjusted odds ratio (aOR) and 95% confidence interval (CI) using multiple logistic regression.

Results

Among participants, 27.7% had previously been treated once with PZQ, 8.2% twice, 2.8% three times, and 3.5% more than three times. Current O. viverrini prevalence was 17% (n = 524). Compared with participants who never used PZQ, the aOR for infection among those who used the drug once was 1.09 (95% CI: 0.88–1.37), twice was 1.19 (95% CI: 0.85–1.68), three times was 1.28 (95% CI: 0.74–2.21), and more than three times was 1.86 (95% CI: 1.18–2.93; P = 0.007).

Conclusions

The population with a frequent history of PZQ use and still continued raw fish consumption showed high levels of repeated reinfection with O. viverrini. They were infected, treated and re-infected repeatedly. These findings suggest that certain participants continue raw fish consumption even after previous infection. This is a particular problem in highly endemic areas for O. viverrini and increases the risk of CCA.

Electronic supplementary material

The online version of this article (10.1186/s40249-019-0529-5) contains supplementary material, which is available to authorized users.

Risk of cholangiocarcinoma in patients undergoing therapeutic endoscopic retrograde cholangiopancreatography or cholecystectomy: A population based study

BACKGROUND

Cholangiocarcinoma is a highly lethal disease that had been underestimated in the past two decades. Many risk factors are well documented for in cholangiocarcinoma, but the impacts of advanced biliary interventions, like endoscopic sphincterotomy (ES), endoscopic papillary balloon dilatation (EPBD), and cholecystectomy, are inconsistent in the previous literature.

AIM

To clarify the risks of cholangiocarcinoma after ES/EPBD, cholecystectomy or no intervention for cholelithiasis using the National Health Insurance Research Database (NHIRD).

METHODS

From data of NHIRD 2004-2011 in Taiwan, we selected 7938 cholelithiasis cases as well as 23814 control group cases (matched by sex and age in a 1:3 ratio). We compared the previous risk factors of cholangiocarcinoma and cholangiocarcinoma rate in the cholelithiasis and control groups. The incidences of total and subsequent cholangiocarcinoma were calculated in ES/EPBD patients, cholecystectomy patients, cholelithiasis patients without intervention, and groups from the normal population.

RESULTS

In total, 537 cases underwent ES/EPBD, 1743 cases underwent cholecystectomy, and 5658 cholelithiasis cases had no intervention. Eleven (2.05%), 37 (0.65%), and 7 (0.40%) subsequent cholangiocarcinoma cases were diagnosed in the ES/EPBD, no intervention, and cholecystectomy groups, respectively, and the odds ratio for subsequent cholangiocarcinoma was 3.13 in the ES/EPBD group and 0.61 in the cholecystectomy group when compared with the no intervention group.

CONCLUSION

In conclusion, symptomatic cholelithiasis patients who undergo cholecystectomy can reduce the incidence of subsequent cholangiocarcinoma, while cholelithiasis patients who undergo ES/EPBD are at a great risk of subsequent cholangiocarcinoma according to our findings.

A novel nomogram for the prediction of intrahepatic cholangiocarcinoma in patients with intrahepatic lithiasis complicated by imagiologically diagnosed mass

Background

Accurate preoperative diagnosis of intrahepatic cholangiocarcinoma (ICC) among patients with imagiologically intrahepatic lithiasis (IHL) complicated by mass is crucial for timely and effective surgical intervention. The aim of the present study was to develop a nomogram to identify ICC associated with IHL (IHL-ICC).

Patients and methods

Data were obtained from a total of 252 consecutive patients with IHL complicated by mass. Multivariate logistic regression analysis was conducted to identify the clinicopathologic and imagiological characteristics that were potentially associated with ICC. A nomogram was developed based on the results of the multivariate analysis, and the value for prediction of ICC was assessed.

Results

The study revealed six potential predictors for IHL-ICC, including comprehensive imagiological diagnosis, biliary tract operation history, fever, ascites, cancer antigen (CA) 19-9, and carcinoembryonic antigen (CEA). The optimal cutoff value was 3.75 μg/L for serum CEA and 143.15 U/mL for serum CA 19-9. The accuracy of the nomogram in predicting ICC was 78.5%. The Youden index provided a value of 0.348, corresponding to a cutoff of 95 points, with an area under the curve of 0.863.

Conclusion

The nomogram holds promise as a novel and accurate tool in identifying IHL-ICC for hepatectomy, and in the differentiation of benign occupying lesions in IHL patients, resulting in the avoidance of unnecessary surgical resection.

New insights into cholangiocarcinoma: multiple stems and related cell lineages of origin

Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies that may develop at any level of the biliary tree. CCA is currently classified into intrahepatic (iCCA), perihilar (pCCA) and distal (dCCA) on the basis of its anatomical location. Notably, although these three CCA subtypes have common features, they also have important inter- and intra-tumor differences that can affect their pathogenesis and outcome. A unique feature of CCA is that it manifests in the hepatic parenchyma or large intrahepatic and extrahepatic bile ducts, furnished by two distinct stem cell niches: the canals of Hering and the peribiliary glands, respectively. The complexity of CCA pathogenesis highlights the need for a multidisciplinary, translational, and systemic approach to this malignancy. This review focuses on advances in the knowledge of CCA histomorphology, risk factors, molecular pathogenesis, and subsets of CCA.

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.

Prognosis of Intrahepatic Cholangiocarcinomas with HBV Infection is Better than Those with Hepatolithiasis After R0 Liver Resection: A Propensity Score Matching Analysis

BACKGROUND

The impact of different causative factors of intrahepatic cholangiocarcinoma (ICC) on disease outcome remains largely unknown. This study aimed to evaluate the prognosis of ICC patients with different pathogenic factors after hepatectomy.

METHODS

Data of 731 consecutive patients undergoing R0 liver resection for ICC at The Eastern Hepatobiliary Surgery Hospital between 2004 and 2010 were analyzed. These patients were divided into the hepatitis B virus-related (HBV-ICC, n = 519), hepatolithiasis-related (stone-ICC, n = 87), HBV plus hepatolithiasis-related (HBV/stone-ICC, n = 45), and other etiologies-related (other-ICC, n = 80) ICC groups. Propensity score matching (PSM) was used to eliminate the baseline differences between these groups.

RESULTS

In these four groups, the 5-year tumor recurrence and overall survival (OS) rates were 75.4, 90.3, 83.0 and 81.9%, and 32.7, 16.3, 17.7 and 22.6%, respectively. The significant differences in recurrence and OS were identified between the HBV- and stone-ICC groups (both p < 0.001). In these two groups, most of the independent prognostic predictors were similar, but tumor diameter >5 cm was demonstrated as a risk factor in the HBV-ICC patients only, and surgical margin <1 cm and human epidermal growth factor receptor 2-positive were demonstrated as risk factors in the stone-ICC patients only. With PSM, 75 patients in each of the HBV- and stone-ICC cohorts were created, and the 5-year recurrence and OS rates were 69.9 versus 88.6, and 34.6 versus 19.2%, respectively (p = 0.017, 0.027).

CONCLUSION

Patients with HBV-ICC achieved better outcomes than those with stone-ICC. This prognostic difference was probably associated with biological malignant invasiveness rather than tumor stage.

Hepatitis B virus is associated with the clinical features and survival rate of patients with intrahepatic cholangiocarcinoma

BACKGROUND AND OBJECTIVE

The pathogenesis and development of intrahepatic cholangiocarcinoma (ICC) may be triggered by hepatitis B virus (HBV). We conducted this retrospective study to explore the potential association between HBV infection and the clinical features and survival rate of patients with ICC.

METHODS

Patients with ICC who had undergone a curative resection were enrolled and divided into three groups according to the seropositivity of the hepatitis B surface antigen (HBsAg) and the hepatitis B core antibody (anti-HBc). The groups were as follows: group I, HBsAg (+)/anti-HBc (+); group II, HBsAg (-)/anti-HBc (+); group III HBsAg (-)/anti-HBc (-). The symptoms, pathologic findings, and outcome information of all patients were retrospectively reviewed. The patient sera were isolated to detect anti-HCV, HBsAg, and anti-HBc. Surgical specimens were assessed by hematoxylin and eosin (HE) staining. The expression of cytokeratin 7 was evaluated by immunohistochemistry. Finally, the 1-, 3-, and 5-year cumulative survival rates were analyzed.

RESULTS

Ninety-seven patients with ICC were enrolled in group I (n=26); group II, (n=50), and group III (n=21). A total of 26.8% (26/97) patients with ICC were positive for HBsAg. Patients with HBV-associated ICC tended to be younger (P=0.018), have lower CA19-9 levels (P=0.000), a higher alpha fetal protein (AFP) level (P=0.012) and prothrombin time (P=0.030), a higher risk of hepatic cirrhosis (P=0.001), and poor differentiation (P=0.028). The 1-, 3-, and 5-year cumulative survival rates for patients within the three groups were as follows: 27.3%, 0%, and 0% for group I, respectively; 62.5%, 30.0%, and 0% for group II, respectively; and 87.5%, 66.7%, and 50.0% for group III, respectively. The results were significantly different in an overall comparison (P=0.000).

CONCLUSION

Patients with HBV-associated ICC showed different clinicopathological features and lower survival rates compared to patients with ICC without HBV infection.

HBV Infection Status and the Risk of Cholangiocarcinoma in Asia: A Meta-Analysis

Background. The inconsistent finding was between hepatitis B virus (HBV) infections and cholangiocarcinoma (CCA). This meta-analysis is to explore this relationship in Asia. Methods. A literature search was performed using PubMed, Web of Science, and Cochrane Library to October 30, 2015. Pooled incidence rate and OR with 95% CI were calculated using STATA 11.0. Results. Thirty-nine studies were included. The pooled incidence rate of CCA patients with HBV infection was 31% (95% CI 22%–39%). The pooled OR showed increased risk of CCA incidence with HBV infection (OR = 2.72, 95% CI 1.90–3.88), especially in ICC (OR = 3.184, 95% CI 2.356–4.302), while it showed no risk in ECC (OR = 1.407, 95% CI 0.925–2.141). Also, the pooled OR showed increased risk of ICC and ECC incidence (OR = 6.857, 95% CI 4.421–10.633 and OR = 1.740, 95% CI 1.260–2.404) in patients with HBsAg+/HBcAb+. The pooled OR showed increased risk of ICC incidence (OR = 1.410, 95% CI 1.095–1.816) in patients with HBsAg−/HBcAb+. Conclusion. It is suggested that HBV infection is associated with an increased risk of CCA in Asia. Two HBV infection models (HBsAg+/HBcAb+ and HBsAg−/HBcAb+) increase the risk of CCA, and patients with HBsAg−/HBcAb+ also had a risk of ICC. This trial is registered with PROSPERO CRD42015029264.

Hepatitis B and Risk of Non-Hepatocellular Carcinoma Malignancy

Chronic hepatitis B infection (CHB) is a known risk factor for malignancy. Unlike hepatocellular carcinoma (HCC), less is known about the risk of non-HCC malignancy. However, epidemiology and pathologic evidence suggests a strong association between non-Hodgkin lymphoma and CHB. Data regarding the risk of other malignancies, such as pancreatic adenocarcinoma and intrahepatic cholangiocarcinoma, are mixed. Surveillance and appropriate treatment of infection and malignancy in these patients is essential. Further study of these associations is needed and may bring new insights in the pathogenesis and treatment of these diseases.

Suppression of trophoblast cell surface antigen 2 enhances proliferation and migration in liver fluke-associated cholangiocarcinoma

BACKGROUND AND AIM

Trophoblast cell surface antigen 2 (TROP2) or tumor-associated calcium signal transducer 2 (TACSTD2) is a 36-kDa type I transmembrane glycoprotein and exerts dual functions as an oncogene and tumor suppressor in cancer cells. In this study, we investigated the expression and functions of TROP2 in liver fluke-associated cholangiocarcinoma (CCA).

MATERIAL AND METHODS

TROP2 expression in 85 CCA tissues was detected by using immunohistochemistry. The methylation status of TROP2 promoter was studied in 15 matched pairs of normal and CCA formalin fixed paraffin embedded (FFPE) tissues using the bisulfite genomic sequencing (BGS) method. The functions of TROP2 on cancer cell behavior were investigated using siRNA in CCA cell lines. Proliferation, migration and invasion assays were performed. A PCR array was used to evaluate the impact of TROP2 knockdown on the gene expression profiles.

RESULTS

TROP2 was highly expressed in all normal bile duct epithelia, but significantly down-regulated in CCA cells. Sixty percent of CCA revealed promoter hypermethylation compared to the corresponding adjacent normal tissues. TROP2 knockdown significantly enhanced the proliferation and migration in CCA cell lines, and altered the expressions of MARCK, EMP1 and FILIP1L.

CONCLUSION

We provide new evidence that TROP2 is epigenetically down-regulated and operates as a negative regulator of cell proliferation and migration in liver fluke-associated CCA.

Multiple cellular origins and molecular evolution of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy associated with unfavorable prognosis and for which no effective treatments are available. Its molecular pathogenesis is poorly understood. Genome-wide sequencing and high-throughput technologies have provided critical insights into the molecular basis of ICC while sparking a heated debate on the cellular origin. Cancer exhibits variabilities in origin, progression and cell biology. Recent evidence suggests that ICC has multiple cellular origins, including differentiated hepatocytes; intrahepatic biliary epithelial cells (IBECs)/cholangiocytes; pluripotent stem cells, such as hepatic stem/progenitor cells (HPCs) and biliary tree stem/progenitor cells (BTSCs); and peribiliary gland (PBG). However, both somatic mutagenesis and epigenomic features are highly cell type-specific. Multiple cellular origins may have profoundly different genomic landscapes and key signaling pathways, driving phenotypic variation and thereby posing significant challenges to personalized medicine in terms of achieving the optimal drug response and patient outcome. Considering this information, we have summarized the latest experimental evidence and relevant literature to provide an up-to-date view of the cellular origin of ICC, which will contribute to establishment of a hierarchical model of carcinogenesis and allow for improvement of the anatomical-based classification of ICC. These new insights have important implications for both the diagnosis and treatment of ICC patients.

Possible association between hepatitis C virus and malignancies different from hepatocellular carcinoma: A systematic review

AIM: To summarize the current knowledge about the potential relationship between hepatitis C virus (HCV) infection and the risk of several extra-liver cancers.

METHODS: We performed a systematic review of the literature, according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) Statement. We extracted the pertinent articles, published in MEDLINE and the Cochrane Library, using the following search terms: neoplasm/cancer/malignancy/tumor/carcinoma/adeno-carcinoma and non-Hodgkin lymphomas, kidney/renal-, cholangio-, pancreatic-, thyroid-, breast-,oral-, skin-, prostate-, lung-, colon-, stomach-, haematologic. Case series, case-series with control-group, case-control, cohort-studies as well as meta-analyses, written in English were collected. Some of the main characteristics of retrieved trials, which were designed to investigate the prevalence of HCV infection in each type of the above-mentioned human malignancies were summarised. A main table was defined and included a short description in the text for each of these tumours, whether at least five studies about a specific neoplasm, meeting inclusion criteria, were available in literature. According to these criteria, we created the following sections and the corresponding tables and we indicated the number of included or excluded articles, as well as of meta-analyses and reviews: (1) HCV and haematopoietic malignancies; (2) HCV and cholangiocarcinoma; (3) HCV and pancreatic cancer; (4) HCV and breast cancer; (5) HCV and kidney cancer; (6) HCV and skin or oral cancer; and (7) HCV and thyroid cancer.

RESULTS: According to available data, a clear correlation between regions of HCV prevalence and risk of extra-liver cancers has emerged only for a very small group of types and histological subtypes of malignancies. In particular, HCV infection has been associated with: (1) a higher incidence of some B-cell Non-Hodgkin-Lymphoma types, in countries, where an elevated prevalence of this pathogen is detectable, accounting to a percentage of about 10%; (2) an increased risk of intra-hepatic cholangiocarcinoma; and (3) a correlation between HCV prevalence and pancreatic cancer (PAC) incidence.

CONCLUSION: To date no definitive conclusions may be obtained from the analysis of relationship between HCV and extra-hepatic cancers. Further studies, recruiting an adequate number of patients are required to confirm or deny this association.

Cholelithiasis and the risk of intrahepatic cholangiocarcinoma: a meta-analysis of observational studies

Background

The etiological factor for intrahepatic cholangiocarcinoma (ICC) is not clear. Although it has been widely accepted that intrahepatic biliary tree stone is associated with increased risk of ICC, the role of extrahepatic biliary tree stone in the incidence of ICC is controversial. In the present study we aim to evaluate the association between pre-existing choledocholithiasis and cholecystolithiasis and the risk of ICC.

Methods

PubMed, Embase, and Web of Science were searched to identify cohort and case–control studies on the association between choledocholithiasis or cholecystolithiasis and the risk of ICC. Studies that met the inclusion criteria were subjected to a meta-analysis performed with Stata statistical software. Either a fixed or random effect model was used, depending on the heterogeneity within the studies. Egger’s test was performed to assess publication bias.

Results

Seven case–control studies met our inclusion criteria. Of the 123,771 participants, 4763 (3.85 %) were patients with ICC, and 119,008 were tumor-free controls. The presence of pre-existing bile duct stones (choledocholithiasis alone or choledocholithiasis accompanied by hepatolithiasis) was associated with the risk of ICC (odds ratio [OR] 17.64, 95 % confidence interval [CI] 11.14–27.95). Even the presence of choledocholithiasis alone (in the absence of hepatolithiasis) was associated with a high risk of ICC (OR 11.79, 95 % CI 4.17–33.35). Cholecystolithiasis may possibly contributed to the incidence of ICC (OR 2.00, 95 % CI 1.16–3.42), with large heterogeneity within studies (I² = 78.5 %).

Conclusions

Bile duct stones including choledocholithiasis are important risk factors for ICC. Careful surveillance of patients with extrahepatic biliary tree stone should be considered.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1870-0) contains supplementary material, which is available to authorized users.

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.

Intrahepatic cholangiocarcinoma and cholangiolocellular carcinoma in cirrhosis and chronic viral hepatitis

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer. Cirrhosis and chronic viral hepatitis are known to be important risk factors for ICC, especially the mass-forming (MF) type of ICC at the periphery of the liver. Cholangiolocellular carcinoma (CoCC) is a rare type of primary liver cancer, which is thought to originate from hepatic progenitor or stem cells. CoCC often exhibits the similar MF type at the periphery of the liver, as ICC, and CoCC is also associated with cirrhosis or chronic viral hepatitis. Better survival rates after surgery have been reported for ICC patients with chronic viral hepatitis than for those without chronic viral hepatitis, although survival rates did not differ significantly in relation to cirrhosis. On the other hand, patients with CoCC had better surgical results than those with MF-type ICC. This review summarizes the clinical characteristics and surgical outcomes of ICC and CoCC associated with cirrhosis or chronic viral hepatitis.

Surgical treatment for intrahepatic cholangiocarcinoma in Europe: a single center experience

Intrahepatic cholangiocarcinoma is the second most common primary liver tumor. The aim of this study was to analyze retrospectively the outcome of surgical treatment and prognostic factors. Clinical, histopathological and treatment data of 221 patients treated from 1995 to 2010 at our institution were investigated. Univariate and multivariate analysis of the patient's data was performed. Patients after R0 and R1 resection presented an overall survival of 67% and 54.5% after 1 year and 40% and 36.4% after 3 years, respectively. The survival of patients without resection of the tumor was dismal with 26% and 3.4% after 1 and 3 years, respectively. Survival after resection was not statistically different in cases with R0 versus R1 resection (P = 0.639, log rank). Univariate Cox regression revealed that higher T stages are a significant hazard for survival (P = 0.048, hazard ratio (HR): 1.211, 95% confidence interval (CI): 1.002-2.465). Patients with tumor recurrence had a significantly inferior long-term survival when compared to patients without recurrence (P < 0.001, log rank). Presence of lymph node metastasis (N1) was an independent prognostic factor for survival after resection in risk-adjusted multivariate Cox regression (P < 0.001, HR: 2.577, 95% CI: 1.742-3.813). Adjuvant chemotherapy did not improve patient survival significantly (P = 0.550, log rank). Surgical resection is still the best treatment option for intrahepatic cholangiocarcinoma regarding the patient's long-term survival. R0 and R1 resection enable both better survival rates when compared to surgical exploration without resection. T status, N status, and tumor recurrence seem to be the most important prognostic factors after resection.

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.

Association of metabolic syndromes and risk factors with ampullary tumors development: A case-control study in China

AIM: To evaluate the risk factors for ampullary adenoma and ampullary cancer.

METHODS: This case-control study included ampullary tumor patients referred to Peking Union Medical College Hospital. Controls were randomly selected from an existing database of healthy individuals at the Health Screening Center of the same hospital. Data on metabolic syndromes, medical conditions, and family history were collected by retrospective review of the patients’ records and health examination reports, or by interview.

RESULTS: A total of 181 patients and 905 age- and sex-matched controls were enrolled. We found that a history of diabetes, cholecystolithiasis, low-density lipoprotein, and apolipoprotein A were significantly related to ampullary adenomas. Diabetes, cholecystolithiasis, chronic pancreatitis, total cholesterol, high-density lipoprotein, and apolipoprotein A were also significantly related to ampullary cancer.

CONCLUSION: Some metabolic syndrome components and medical conditions are potential risk factors for the development of ampullary tumors. Cholelithiasis, diabetes, and apolipoprotein A may contribute to the malignant transformation of benign ampullary adenomas into ampullary cancer.

Staging, prognostic factors and adjuvant therapy of intrahepatic cholangiocarcinoma after curative resection

BACKGROUND & AIMS

Prognostic factors and adjuvant therapy of intrahepatic cholangiocarcinoma (ICC) after curative resection were not clear. We aim to analyse prognostic factors after curative resection and evaluate adjuvant therapy and survival based on the new staging system.

METHODS

A retrospective analysis of 283 patients who underwent surgical exploration for ICC was performed. Staging was performed according to the 7th edition AJCC staging manual. Univariate and multivariate analyses were used to evaluate independent prognostic factors.

RESULTS

The difference for OS at different TNM stages after R0 resection was significant (P < 0.001). Despite regional lymph node metastasis, tumour number and vascular invasion, serum GGT level was also an independent prognostic factor for OS of patients after R0 resection. The incidence of biliary and vascular invasion was significantly higher in high GGT group than in normal GGT group. Factors predictive of recurrence were multiple tumours and regional lymph node metastasis. After R0 resection, adjuvant TACE not only did not improve the OS of patients at TNM stage I (P = 0.508), but significantly promoted recurrence of these patients (P = 0.006). Only patients at TNM stage II, III and IV benefited from adjuvant TACE for longer survival, while the recurrence rates were not affected.

CONCLUSIONS

The new staging system can predict the survival of ICC patients after R0 resection. High GGT level may be suggestive of biliary and vascular invasion and was an independent risk factor for OS after R0 resection. Adjuvant TACE may be indicated only for patients at advanced stages for better survival.

Hepatitis B virus infection and intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a devastating malignant tumor arising from the peripheral intrahepatic bile duct epithelium. The incidence and mortality of ICC is markedly increasing over the past two decades worldwide, though the cause for this rise in incidence is unclear, thus intensifying the search for alternative etiological agents and pathogenetic mechanisms. Hepatolithiasis, primary sclerosing cholangitis, parasitic infection (Opisthorchis viverrini or Clonorchis sinensis), fibropolycystic liver disease, and chemical carcinogen exposure are thought to be the risk factors for ICC. Nevertheless, the majority of ICC patients do not have any of these risk factors, and none of the established risk factors can explain the recent increasing trend of ICC. Therefore, identifying other risk factors may lead to the prevention and early detection of ICC. Chronic hepatitis B virus (HBV) infection is the predominant cause of hepatocellular carcinoma in HBV-endemic areas. This review discusses the evidence implicating chronic HBV infection as a likely etiology of ICC and the pathogenetic mechanisms that might be involved.

Expression of GLP-1R protein and its clinical role in intrahepatic cholangiocarcinoma tissues

The study investigates the expression and clinical role of GLP-1R in intrahepatic cholangiocarcinoma (ICC) tissues. ICC tissue, tissue around tumour and normal liver tissue samples from 176 ICC patients were investigated for GLP-1R expression by immunohistochemistry and western blots. Expression levels were correlated to clinical variables and to the postoperative outcome. High GLP-1R expression levels were detected in tumor tissue samples. Kaplan-Meier method was used for survival analysis of patients follow-up data. Results showed that median survival time of patients with high GLP-1R positive expression in ICC tissue were 22 months. Median survival time of patients with low GLP-1R positive expression in ICC tissue were 19.8 months. There wasn't statistical difference (p = 0.332) between two groups. Immunohistochemistry semi-quantitative analysis showed that tissue differentiation is not prognostic risk factors. In patients with GLP-1R positive expression in ICC tissue, lymph node metastasis was important prognostic factors (p = 0.001). Although statistical analysis showed that GLP-1R can not be judged as a risk prognostic factors, GLP-1 might become a new target for therapy of ICC.

Epigenetic therapy with the histone methyltransferase EZH2 inhibitor 3-deazaneplanocin A inhibits the growth of cholangiocarcinoma cells

Enhancer of zeste homolog 2 (EZH2) is involved in malignant transformation and the biological aggressiveness of several human malignancies. Growing evidence indicates that EZH2 may be an appropriate therapeutic target for malignancies, including cholangiocarcinoma. Recently, an S-adenosyl-L-homocysteine hydrolase inhibitor, 3-deazaneplanocin A (DZNep) was shown to deplete and inhibit EZH2. The aim of this study was to determine the effect of DZNep and the combination of gemcitabine and DZNep in cholangiocarcinoma cells. The effects of DZNep and its combination with gemcitabine were assessed in the cholangiocarcinoma cell lines RBE and TFK-1. DZNep depleted the cellular levels of EZH2 and inhibited the associated histone H3 lysine 27 trimethylation. DZNep treatment resulted in the inhibition of proliferation in the cholangiocarcinoma cell lines, and the combination of DZNep and gemcitabine showed synergistic inhibition of cell proliferation. DZNep induced apoptosis and G1 phase cell cycle arrest in cholangiocarcinoma cells, and the combination of DZNep and gemcitabine enhanced the induced apoptosis and G1 arrest when compared with gemcitabine alone. Inhibition of cell proliferation by DZNep was partially associated with upregulation of p16INK4a and p17KIP1. The present study shows that DZNep inhibits cell proliferation by inducing G1 arrest and apoptosis. These results indicate that an epigenetic therapy that pharmacologically targets EZH2 via DZNep may constitute a novel approach for the treatment of cholangiocarcinoma.

Smoking, alcohol consumption, and the risk of extrahepatic cholangiocarcinoma: A meta-analysis

AIM: To assess the association between smoking and alcohol consumption and extrahepatic cholangiocarcinoma (ECC) through a meta-analysis of clinical observational studies.

METHODS: A literature search was conducted using Embase and MEDLINE databases from inception to 31 May 2013 without language limitations, and by manually searching the references of retrieved articles. Case-control and cohort studies that investigated the association between smoking or alcohol consumption and ECC were included. The quality of these studies was assessed using the Newcastle-Ottawa quality assessment scale. Summary relative risks and corresponding 95%CI were calculated using a random-effects model. Publication bias was assessed by Begg’s funnel plot and Egger’s test.

RESULTS: A total of 12 eligible articles (11 case-control studies and one cohort study) were included in this meta-analysis. Eleven studies reported the association between smoking and ECC. Pooled analysis indicated that smokers had an increased risk of ECC development as compared with non-smokers (summary RR = 1.23; 95%CI: 1.01-1.50). This correlation was present in population-based studies (n = 5; summary RR = 1.47; 95%CI: 1.06-2.05) but not in hospital-based studies (n = 6; summary RR = 1.10; 95%CI: 0.88-1.37) and in non-Asian regions (n = 7; summary RR = 1.39; 95%CI: 1.03-1.87) but not in Asia (n = 4; summary RR = 1.08; 95%CI: 0.85-1.38). Seven studies reported an association between consuming alcohol and ECC. Pooled analysis indicated that alcohol drinkers had a similar risk of ECC development as did individuals who did not drink alcohol (summary RR = 1.09; 95%CI: 0.87-1.37). There was moderate heterogeneity among the studies and no evidence of publication bias.

CONCLUSION: Smoking is associated with an increased risk of ECC, but alcohol consumption is not. Further population-based studies, particularly cohort studies, are warranted to enable definitive conclusions.

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.