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

The Constellation of Risk Factors and Paraneoplastic Syndromes in Cholangiocarcinoma: Integrating the Endocrine Panel Amid Tumour-Related Biology (A Narrative Review)

Cholangiocarcinomas (CCAs), a heterogeneous group of challenging malignant tumours which originate from the biliary epithelium, are associated with an alarming increasing incidence during recent decades that varies between different regions of the globe. Thus, awareness represents the key operating factor. Our purpose was to overview the field of CCAs following a double perspective: the constellation of the risk factors, and the presence of the paraneoplastic syndromes, emphasizing the endocrine features amid the entire multidisciplinary panel. This is a narrative review. A PubMed-based search of English-language original articles offered the basis of this comprehensive approach. Multiple risk factors underlying different levels of statistical evidence have been listed such as chronic biliary diseases and liver conditions, inflammatory bowel disease, parasitic infections (e.g., Opisthorchis viverrini, Clonorchis sinensis), lifestyle influence (e.g., alcohol, smoking), environmental exposure (e.g., thorotrast, asbestos), and certain genetic and epigenetic interplays. With regard to the endocrine panel, a heterogeneous spectrum should be taken into consideration: non-alcoholic fatty liver disease, obesity, type 2 diabetes mellitus, and potential connections with vitamin D status, glucagon-like peptide 1 receptor, or the galanin system, respectively, with exposure to sex hormone therapy. Amid the numerous dermatologic, hematologic, renal, and neurologic paraneoplastic manifestations in CCAs, the endocrine panel is less described. Humoral hypercalcaemia of malignancy stands as the most frequent humoral paraneoplastic syndrome in CCAs, despite being exceptional when compared to other paraneoplastic (non-endocrine) manifestations and to its reported frequency in other (non-CCAs) cancers (it accompanies 20-30% of all cancers). It represents a poor prognosis marker in CCA; it may be episodic once the tumour relapses. In addition to the therapy that targets the originating malignancy, hypercalcaemia requires the administration of bisphosphonates (e.g., intravenous zoledronic acid) or denosumab. Early detection firstly helps the general wellbeing of a patient due to a prompt medical control of high serum calcium and it also provides a fine biomarker of disease status in selected cases that harbour the capacity of PTHrP secretion. The exact molecular biology and genetic configuration of CCAs that display such endocrine traits is still an open matter, but humoral hypercalcaemia adds to the overall disease burden.

Current and Future Therapeutic Targets for Directed Molecular Therapies in Cholangiocarcinoma

We conducted a comprehensive review of the current literature of published data, clinical trials (MEDLINE; ncbi.pubmed.com), congress contributions (asco.org; esmo.org), and active recruiting clinical trains (clinicaltrial.gov) on targeted therapies in cholangiocarcinoma. Palliative treatment regimens were analyzed as well as preoperative and perioperative treatment options. We summarized the current knowledge for each mutation and molecular pathway that is or has been under clinical evaluation and discussed the results on the background of current treatment guidelines. We established and recommended targeted treatment options that already exist for second-line settings, including IDH-, BRAF-, and NTRK-mutated tumors, as well as for FGFR2 fusion, HER2/neu-overexpression, and microsatellite instable tumors. Other options for targeted treatment include EGFR- or VEGF-dependent pathways, which are known to be overexpressed or dysregulated in this cancer type and are currently under clinical investigation. Targeted therapy in CCA is a hallmark of individualized medicine as these therapies aim to specifically block pathways that promote cancer cell growth and survival, leading to tumor shrinkage and improved patient outcomes based on the molecular profile of the tumor.

Systematic replication of smoking disease associations using survey responses and EHR data in the All of Us Research Program

OBJECTIVE

The All of Us Research Program (All of Us) aims to recruit over a million participants to further precision medicine. Essential to the verification of biobanks is a replication of known associations to establish validity. Here, we evaluated how well All of Us data replicated known cigarette smoking associations.

MATERIALS AND METHODS

We defined smoking exposure as follows: (1) an EHR Smoking exposure that used International Classification of Disease codes; (2) participant provided information (PPI) Ever Smoking; and, (3) PPI Current Smoking, both from the lifestyle survey. We performed a phenome-wide association study (PheWAS) for each smoking exposure measurement type. For each, we compared the effect sizes derived from the PheWAS to published meta-analyses that studied cigarette smoking from PubMed. We defined two levels of replication of meta-analyses: (1) nominally replicated: which required agreement of direction of effect size, and (2) fully replicated: which required overlap of confidence intervals.

RESULTS

PheWASes with EHR Smoking, PPI Ever Smoking, and PPI Current Smoking revealed 736, 492, and 639 phenome-wide significant associations, respectively. We identified 165 meta-analyses representing 99 distinct phenotypes that could be matched to EHR phenotypes. At P < .05, 74 were nominally replicated and 55 were fully replicated. At P < 2.68 × 10-5 (Bonferroni threshold), 58 were nominally replicated and 40 were fully replicated.

DISCUSSION

Most phenotypes found in published meta-analyses associated with smoking were nominally replicated in All of Us. Both survey and EHR definitions for smoking produced similar results.

CONCLUSION

This study demonstrated the feasibility of studying common exposures using All of Us data.

Association between Smoking Cessation and the Risk of Cholangiocarcinoma and Ampulla of Vater Cancer: A Nationwide Cohort Study

Introduction

The association between smoking cessation and intrahepatic and extrahepatic cholangiocarcinoma (iCCA and eCCA) risk is unclear. Furthermore, the association in individuals with preexisting risk factors is unknown. We aimed to investigate the association between smoking status (especially smoking cessation) and CCA risk according to individuals' glycemic status.

Methods

In this nationwide cohort study, 9,520,629 adults without cancer who underwent national health screening by the Korean National Health Insurance Service in 2009 were followed up through 2018. The hazard ratios (HRs) and 95% confidence intervals (CIs) for CCA were estimated after adjusting for potential confounders.

Results

During the 78.3 person-years of follow-up, 16,236 individuals were newly diagnosed with CCA. Quitters had a significantly lower risk of iCCA and eCCA compared to current smokers in all glycemic status groups (all p < 0.01). The HRs (95% CIs) for iCCA in current smokers and quitters were 1.33 (1.24-1.43) versus 0.98 (0.90-1.06) in individuals with normoglycemia, 1.49 (1.37-1.63) versus 1.17 (1.06-1.28) in individuals with prediabetes, and 2.15 (1.96-2.37) versus 1.58 (1.42-1.75) in individuals with diabetes, compared to never-smokers with normoglycemia. Current smokers with diabetes or prediabetes had a synergistically increased risk of iCCA (all p < 0.01). However, quitters with diabetes and prediabetes had an iCCA risk comparable to that of never-smokers. Analysis of eCCA yielded similar results. Smoking was not independently associated with the risk of the ampulla of Vater cancer. However, smoking combined with diabetes or prediabetes was associated with an increased risk of the ampulla of Vater cancer (all p < 0.05).

Conclusion

Smoking cessation was associated with a reduced risk of CCA, despite the synergistically increased risk in current smokers with diabetes and prediabetes. Our findings suggest a crucial opportunity to reduce the risk of CCA. More individualized and intensive cancer prevention education is needed against CCA.

Clinicopathological features and management of biliary cystic tumors of the liver: a single-center experience

BACKGROUND

Biliary cystic neoplasms (BCNs) of the liver are rare pathologies encountered in hepatobiliary surgeries. Till now, there is a lack of definitive criteria used to differentiate biliary cystadenoma (BCA) from biliary cystadenocarcinoma (BCAC).

METHODS

In the period between 2005 and 2018, the data of consecutive patients diagnosed with BCA and BCAC were retrospectively reviewed.

RESULTS

A total of 62 patients underwent surgical management for BCNs. BCA was diagnosed in 50 patients while 12 patients had BCAC. Old age, male gender, smoking, and abdominal pain were strongly associated with BCAC. Left lobe location, small size, with the presence of mural nodule, and solid component were significantly noticed with BCAC. A novel pre-operative score was developed to predict the susceptibility for BCAC and help us to identify the optimal surgical strategy. Blood loss, operative time, and complications were comparable between the two study groups.

CONCLUSION

Mural nodules or solid components are suggestive of BCAC. Complete surgical resection of cystic tumors of the liver is mandatory due to malignant potential of the lesion and for prolonged survival.

Lifestyle, body mass index, diabetes, and the risk of pancreatic cancer in a nationwide population-based cohort study with 7.4 million Korean subjects

BACKGROUND

Large-scale epidemiological studies on pancreatic cancer in non-Western populations are insufficient. We investigated the risk factors for pancreatic cancer.

METHODS

Using the Korean National Health Insurance database, subjects who participated in the health examination program between 2005 and 2006 were identified and followed up until 2017. Adjusted hazard ratios (HRs) for pancreatic cancer risk were estimated using a Cox proportional hazards model.

RESULTS

During 11.5 years follow-up, 22,543 of 7,445,947 participants were newly diagnosed with pancreatic cancer. Compared with normal-weight subjects, pancreatic cancer risk was increased in those with severe obesity (BMI ≥ 28 kg/m2) (HR = 1.16; 95% CI, 1.11-1.23). Subjects with diabetes had an increased risk compared with those without diabetes (HR = 1.48; 95% CI, 1.43-1.53). Current smokers had a higher risk than never smokers (HR = 1.43; 95% CI, 1.38-1.48). Current smoking combined with diabetes increased the risk compared with never smokers without diabetes (HR = 2.13; 95% CI, 2.00-2.28). Current smoking combined with BMI ≥ 25 kg/m2 had an increased risk compared with never smokers with BMI < 23 kg/m2 (HR = 1.55; 95% CI, 1.46-1.65).

CONCLUSION

Smoking, obesity, and diabetes are significant risk factors for pancreatic cancer in Koreans. Lifestyle modifications for smoking and obesity would be beneficial for pancreatic cancer prevention.

Association between Metabolic Disorders and Cholangiocarcinoma: Impact of a Postulated Risk Factor with Rising Incidence

Introduction and objectives: The incidence of cholangiocarcinoma (CCA) has been increasing globally. Although a concomitant increase in the incidence of metabolic disorders might suggest a causal relationship, the data are scarce. We aimed to describe the prevalence of metabolic disorders in patients with CCA and report the clinical features and outcomes. Patients and Methods: Retrospective study including patients with CCA. Patients were divided into: (1) past history of diabetes or/and overweight/obesity (“metabolic disorder group”) and (2) without any of these features (“non-metabolic-disorder group”). A Cox regression model was used to determine the prognostic factors. Results: 122 patients were included. In total, 36 (29.5%) had overweight/obesity, 24 (19.7%) had diabetes, and 8 (6.6%) had both. A total of 29 (23.8%) patients had resectable disease and received upfront surgery. A total of 104 (85.2%) received chemotherapy for advanced/recurrent disease. The overall survival of the cohort was 14.3 months (95% CI: 10.1−17.3). ECOG-PS 0 (p < 0.0001), resectable disease (p = 0.018) and absence of vascular invasion (p = 0.048) were independently associated with better prognosis. The “metabolic disorder group” (n = 52) had a median survival of 15.5 months (95% CI 10.9−33.9) vs. 11.5 months (95% CI 8.4−16.5) in the “non-metabolic-disorder group” (n = 70) (HR: 1.10; 95% CI 0.62−1.94). Patients with resectable disease in the “metabolic group” had longer survival than patients in the “non-metabolic group” (43.4 months (95% CI 33.9-NR) vs. 21.8 months (95% CI 8.6−26.9); HR = 0.12, 95% CI 0.03−0.59). Conclusion: Metabolic disorders are frequent among CCA patients. Underlying metabolic comorbidities may be associated with prognosis in resectable CCA. There is a need to explore the mechanism that drives CCA carcinogenesis in a metabolic background.

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.

Associations Between Residential Exposure to Volatile Organic Compounds and Liver Injury Markers

Occupational exposures to volatile organic compounds (VOCs) have been associated with numerous health complications including steatohepatitis and liver cancer. However, the potential impact of environmental/residential VOC exposures on liver health and function is largely unknown. To address this knowledge gap, the objective of this cross-sectional study is to investigate associations between VOCs and liver injury biomarkers in community residents. Subjects were recruited from six Louisville neighborhoods, and informed consent was obtained. Exposure biomarkers included 16 creatinine-adjusted urinary metabolites corresponding to 12 parent VOCs. Serological disease biomarkers measured included cytokertain-18 (K18 M65 and M30), liver enzymes, and direct bilirubin. Associations between exposure and disease biomarkers were assessed using generalized linear models. Smoking status was confirmed through urinary cotinine levels. The population comprised of approximately 60% females and 40% males; White persons accounted 78% of the population; with more nonsmokers (n = 413) than smokers (n = 250). When compared with nonsmokers, males (45%) and Black persons (26%) were more likely to be smokers. In the overall population, metabolites of acrolein, acrylonitrile, acrylamide, 1,3-butadiene, crotonaldehyde, styrene, and xylene were positively associated with alkaline phosphatase. These associations persisted in smokers, with the exception of crotonaldehyde, and addition of N,N-dimethylformamide and propylene oxide metabolites. Although no positive associations were observed for K18 M30, the benzene metabolite was positively associated with bilirubin, irrespective of smoking status. Taken together, the results demonstrated that selected VOCs were positively associated with liver injury biomarkers. These findings will enable better risk assessment and identification of populations vulnerable to liver disease.

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.

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.

Comprehensive Review of Molecular Mechanisms during Cholestatic Liver Injury and Cholangiocarcinoma

Cholestatic liver injury is characterized by damage induced on the biliary tree and cholangiocytes, the cells lining the biliary tree, thus they are termed "cholangiopathies". Cholangiopathies include diseases such as Primary Biliary Cholangitis, Primary Sclerosing Cholangitis, Biliary Atresia and Cholangiocarcinoma. These pathologies lack viable therapies and most patients are diagnosed during late stage disease progression (with the exception of Biliary Atresia, which is found shortly after birth). The lack of therapies for these diseases has put a significant burden on the need for liver transplantation as this is the only indicative "cure" for cholangiopathies. The molecular mechanisms for cholangiopathies have been extensively studied; however, and unfortunately, the lack of effective biomarkers and therapeutics remains. In this review article we highlight the latest studies to investigate the molecular mechanisms regulating cholangiopathies and the potential therapeutics that might be discovered.