Smoking, Alcohol Consumption, and Risks for Biliary Tract Cancer and Intrahepatic Bile Duct Cancer

Alcohol-associated liver cancer

Heavy alcohol intake induces a wide spectrum of liver diseases ranging from steatosis, steatohepatitis, cirrhosis, and HCC. Although alcohol consumption is a well-known risk factor for the development, morbidity, and mortality of HCC globally, alcohol-associated hepatocellular carcinoma (A-HCC) is poorly characterized compared to viral hepatitis-associated HCC. Most A-HCCs develop after alcohol-associated cirrhosis (AC), but the direct carcinogenesis from ethanol and its metabolites to A-HCC remains obscure. The differences between A-HCC and HCCs caused by other etiologies have not been well investigated in terms of clinical prognosis, genetic or epigenetic landscape, molecular mechanisms, and heterogeneity. Moreover, there is a huge gap between basic research and clinical practice due to the lack of preclinical models of A-HCC. In the current review, we discuss the pathogenesis, heterogeneity, preclinical approaches, epigenetic, and genetic profiles of A-HCC, and discuss the current insights into and the prospects for future research on A-HCC. The potential effect of alcohol on cholangiocarcinoma and liver metastasis is also discussed.

Risk for Second Primary Ovarian Cancer: A Large Population Based on Surveillance, Epidemiology, and End Results Database

INTRODUCTION

This study aims to evaluate the likelihood of developing a second primary ovarian cancer (OC) considering factors including age, race, and the types of initial malignancies encountered.

METHODS

This study employed a retrospective cohort approach, compiling data on individuals diagnosed with OC from the Surveillance, Epidemiology, and End Results (SEER) program databases spanning the years 1975-2019. The analysis used standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) to determine the likelihood of developing OC. The result was further refined by categorizing the data based on patient age, race background, first primary cancer types, the time elapsed since the second primary cancer diagnosis, and radiotherapy treatment.

RESULTS

A total of 1,536,151 patients with second primary cancer being OC were included. The SIR of the second primary OC was observed to be elevated among patients between the ages of 18-64 years (SIR: 1.09, 95% CI: 1.06-1.13). In contrast, for patients who were 65 years of age or older, the SIR for a second primary OC was found to be relatively lower (SIR: 0.87, 95% CI: 0.83-0.91). A lowering, however, not statistically significant, of the SIR of the second primary OC in patients with white race was presented. Within 2 months to 1-year diagnosis interval, the SIR of the second primary OC was highest (SIR: 1.48, 95% CI: 1.37-1.61). Liver, gallbladder, intrahepatic, and other bile ducts (SIR: 2.00, 95% CI: 1.38-2.81), and breast cancer (SIR: 1.20, 95% CI: 1.15-1.25) had higher SIRs of second primary OC.

CONCLUSION

This study identifies age, ethnicity, the time span between the diagnoses, and the types of initial cancers as factors correlated with the occurrence of a second primary OC. Our findings suggest that targeted surveillance should be considered for high-risk groups.

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.

Research progress and prospect of postoperative adjuvant therapy for resectable intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary malignancy of the liver, following hepatocellular carcinoma (HCC). Surgical resection remains the only potentially curative treatment for ICC. However, due to its high malignancy and propensity for postoperative recurrence, the prognosis for ICC is generally poor, and there is currently little standardized approach for adjuvant therapy following curative surgery. This article aims to explore adjuvant treatment strategies for ICC post-curative surgery by reviewing retrospective studies and clinical trials conducted in recent years. The analysis focuses on the effectiveness, challenges, and potential developments in the management of ICC post-surgery, considering the high recurrence rates and the need for improved therapeutic approaches to enhance patient outcomes. Additionally, we discuss the various types of adjuvant treatments that have been explored, including chemotherapy, radiation therapy, and targeted therapies. The goal is to provide a comprehensive overview of the current landscape and highlight promising directions for future research to improve survival and quality of life for ICC patients.

Bile ductal mucosal dysplasia is a possible risk factor for adenocarcinoma in patients with adenomyomatous hyperplasia of the Vaterian system: a single-centre study from China

BACKGROUND

The relationship between adenomyomatous hyperplasia of the Vaterian system(AV) and cancer is unclear, some reports suggest that AV is often combined with mucosal glandular dysplasia, but it is not clear whether mucosal glandular dysplasia is a risk factor for carcinogenesis of AV. The aim of this study was to retrospective analysis of role of ductal glandular dysplasia as a risk factor in the development of carcinoma in AV.

METHODS

A total of 328 cases who underwent surgery with a final pathological diagnosis of adenomyomatous hyperplasia (AH) in the Chinese PLA General Hospital in BeiJing, China, between January 2005 and December 2021 were retrospectively collected. There were Seventeen cases(5%) in which the lesions were located in the common bile duct as well as the ampulla of Vater, and their clinical (age, sex, etc.), imaging (cholelithiasis, etc.) and pathological data (mucosal glandular dysplasia, etc.) were collected. Clinical data and pathological features of AV with or without mucosal glandular dysplasia were analyzed.

RESULTS

There were 17 out of 328 cases of AH occurring in the Vaterian system (5%). Three of seventeen AV cases were associated with carcinoma (18%). Of three cases, two (12%) with the tumor lesions in the mucosal glands adjacent to the AH (biliary tract cancer and ampullary cancer), and one (6%) with carcinoma developed from AH itself in the ampulla of Vater. All carcinomas had adenomyomatous hyperplasia with nearby mucosal glandular dysplasia (MGD). The percentage of BTC or AC was higher in patients with concurrent AH and MGD compared to AH patients without MGD. The results show tendency toward statistical significance (P = 0.082). This difference was more obvious among AH with severe dysplasia compared to adenomyomatous hyperplasia with mild-moderate dysplasia (P = 0.018).

CONCLUSION

This study is the first to find that AV is associated with biliary tract cancer and ampullary cancer. In AV, the mucosal glandular dysplasia may be a risk factor for the development of malignancy. The underlying mechanism for carcinogenesis of AV could be AH itself or its secretions stimulating mucosal glands hyperplasia, then mucosal glands dysplasia. AV may be a precancerous lesion.

Independent of Primary Sclerosing Cholangitis and Cirrhosis, Early Adulthood Obesity Is Associated with Cholangiocarcinoma

BACKGROUND

It is estimated that 6% to 20% of all cholangiocarcinoma (CCA) diagnoses are explained by primary sclerosing cholangitis (PSC), but the underlying risk factors in the absence of PSC are unclear. We examined associations of different risk factors with intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC) in the United States.

METHODS

We conducted a case-control study of 121 patients with ECC and 308 patients with ICC treated at MD Anderson Cancer Center between May 2014 and March 2020, compared with 1,061 healthy controls. Multivariable logistic regression analysis was applied to estimate the adjusted OR (AOR) and 95% confidence interval (CI) for each risk factor.

RESULTS

Being Asian, diabetes mellitus, family history of cancer, and gallbladder stones were associated with higher odds of developing ICC and ECC. Each 1-unit increase in body mass index in early adulthood (ages 20-40 years) was associated with a decrease in age at diagnosis of CCA (6.7 months, P < 0.001; 6.1 months for ICC, P = 0.001; 8.2 months for ECC, P = 0.007). A family history of cancer was significantly associated with the risk of ICC and ECC development; the AORs (95% CI) were 1.11 (1.06-1.48) and 1.32 (1.01-2.00) for ICC and ECC, respectively.

CONCLUSIONS

In this study, early adulthood onset of obesity was significantly associated with CCA and may predict early diagnosis at younger age than normal weight individuals.

IMPACT

The study highlights the association between obesity and CCA, independent of PSC. There is a need to consider the mechanistic pathways of obesity in the absence of fatty liver and cirrhosis.

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.

Threshold dose-response association between smoking pack-years and the risk of gallbladder cancer: A nationwide cohort study

BACKGROUND AND AIMS

The association between smoking and gallbladder cancer (GBC) risk is unclear. We investigated the association between smoking (including pack-years) and GBC risk. We also examined the combined effects of smoking and diabetes or prediabetes on GBC risk.

METHODS

This Korean nationwide cohort study included 9,520,629 adults without cancer who underwent national health screening in 2009 and were followed-up until 2018. Multivariable Cox proportional hazards models were used to determine risk estimates after adjusting for potential confounders.

RESULTS

During 78.4 million person-years (mean 8.2 ± 0.9 years) of follow-up, we identified 6066 patients with newly diagnosed GBC. Current and former smokers were associated with increased GBC risk (hazard ratio [HR], 95% confidence interval [CI]: 1.117, 1.029-1.212 and 1.105, 1.016-1.202, respectively). Smoking of 20 to <30 and ≥30 pack-years was independently associated with increased GBC risk compared with never smoking (HR, 95% CI; 1.241, 1.100-1.400 and 1.231, 1.107-1.370, respectively). However, smoking of <10 and 10 to <20 pack-years was not. This threshold dose-response association between smoking pack-years and GBC risk was observed regardless of the glycaemic status (all P < 0.01). Furthermore, smoking of ≥20 pack-years and hyperglycaemia had a synergistic effect on the GBC risk (all P < 0.01). Smokers with ≥20 pack-years with diabetes had the highest risk of GBC compared to never smokers with normoglycaemia (HR, 1.658; 95% CI, 1.437-1.914).

CONCLUSIONS

Smoking was associated with increased GBC risk with a threshold dose-response effect for smoking pack-years. The risk of GBC increases synergistically when smoking and hyperglycaemia coexist. More individualised cancer prevention education is required to reduce GBC risk.

Associations between cigarette smoking and biliary tract cancer by anatomic subsite and sex: a prospective cohort study in Japan

PURPOSE

Biliary tract cancer (BTC) has not been considered a tobacco-related cancer, largely because of inconclusive results from epidemiological studies. We herein evaluate the association between cigarette smoking and risk of death from BTC by anatomic subsite and sex using data from a large, prospective cohort study in Japan.

METHODS

The present study included 97,030 Japanese individuals who were enrolled in 1988-1990 and followed until 31 December 2009. Cox proportional hazards regression models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for the association of BTC with cigarette smoking, including smoking status, number of cigarettes smoked per day, and pack-years of smoking.

RESULTS

During a mean follow-up of 16.2 years, we documented 484 deaths (187 from gallbladder cancers and 297 from cancers of other and unspecified biliary tract parts). After adjustment for sex, age, body mass index, alcohol consumption, and history of gallstones, current smokers had a higher risk of death due to BTC (RR = 1.35, 95% CI = 1.01-1.79) than never smokers. In the analyses by anatomic subsite, current smoking was associated with an increased risk of death from gallbladder cancer (RR = 1.89 95% CI = 1.19-3.02), whereas no evidence of an association was noted for cancers of other and unspecified biliary tract parts (RR = 1.10, 95% CI = 0.77-1.58). Moreover, mortality risk increased with an increasing number of cigarettes smoked per day and pack-years of smoking, particularly for gallbladder cancer in men.

CONCLUSION

Cigarette smoking is associated with an increased risk of death from BTC, particularly gallbladder cancer, in Japanese men.

Neoadjuvant and Adjuvant Therapy in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer and causes major economic and health burdens throughout the world. Although the incidence of ICC is relatively low, an upward trend has been seen over the past few decades. Owing to the lack of specific manifestations and tools for early diagnosis, most ICC patients have relatively advanced disease at diagnosis. Thus, neoadjuvant therapy is necessary to evaluate tumor biology and downstage these patients so that appropriate candidates can be selected for radical liver resection. However, even after radical resection, the recurrence rate is relatively high and is a main cause leading to death after surgery, which makes adjuvant therapy necessary. Because of its low incidence, studies in both neoadjuvant and adjuvant settings of ICC are lagging compared with other types of malignancy. While standard neoadjuvant and adjuvant regimens are not available in the current guidelines due to a lack of high-level evidence, some progress has been achieved in recent years. In this review, the available literature on advances in neoadjuvant and adjuvant strategies in ICC are evaluated, and possible challenges and opportunities for clinical and translational investigations in the near future are discussed.

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Molecular Mechanisms Linking Risk Factors to Cholangiocarcinoma Development

The poor prognosis of cholangiocarcinoma in humans is related to several factors, such as (i) the heterogeneity of the disease, (ii) the late onset of symptoms and (iii) the limited comprehension of the carcinogenic pathways determining neoplastic changes, which all limit the pursuit of appropriate treatment. Several risk factors have been recognized, including different infective, immune-mediated, and dysmorphogenic disorders of the biliary tree. In this review, we report the details of possible mechanisms that lead a specific premalignant pathological condition to become cholangiocarcinoma. For instance, during liver fluke infection, factors secreted from the worms may play a major role in pathogenesis. In primary sclerosing cholangitis, deregulation of histamine and bile-acid signaling may determine important changes in cellular pathways. The study of these molecular events may also shed some light on the pathogenesis of sporadic (unrelated to risk factors) forms of cholangiocarcinoma, which represent the majority (nearly 75%) of cases.

Association of the Frequency and Quantity of Alcohol Consumption With Gastrointestinal Cancer

IMPORTANCE

Although total alcohol consumption is a known risk factor for gastrointestinal (GI) cancers, few studies have attempted to assess the pattern of alcohol drinking in association with GI cancers.

OBJECTIVE

To evaluate the relative association of the frequency of drinking vs the amount of alcohol consumed per occasion with the development of GI cancers.

DESIGN, SETTING, AND PARTICIPANTS

A population-based retrospective cohort study used data from the Korean National Health Insurance System database on 11 737 467 participants without cancer who underwent a national health screening program from January 1, 2009, to December 31, 2010. Participants were followed up from the year after their health screening date until they received a diagnosis of GI cancer, death, or December 31, 2017. The median follow-up duration was 6.4 years (interquartile range, 6.4-7.4 years). Statistical analysis was performed from January 1, 2019, to March 31, 2020.

EXPOSURES

Weekly alcohol consumption (nondrinker [0 g/week], mild drinker [0-104 g/week], moderate drinker [105-209 g/week], and heavy drinker [≥210 g/week]), drinking frequency, and amount per occasion.

MAIN OUTCOMES AND MEASURES

Incident GI cancers at 6 specific sites (esophagus, stomach, colorectal, liver, biliary, and pancreas).

RESULTS

Among 11 737 467 participants (6 124 776 women [52.2%]; mean [SD] age, 54.6 [10.4] years), 319 202 (2.7%) developed GI cancer. Compared with nondrinkers, the risk of GI cancer was higher for mild drinkers (adjusted hazard ratio [aHR], 1.04; 95% CI, 1.03-1.05), moderate drinkers (aHR, 1.14; 95% CI, 1.12-1.15), and heavy drinkers (aHR, 1.28; 95% CI, 1.26-1.29). The risk of GI cancer increased linearly with the frequency of drinking in a dose-dependent manner (aHR, 1.39; 95% CI, 1.36-1.41 for individuals who drink every day). In contrast, the risk of GI cancer appeared to increase with consumption up to 5 to 7 units per occasion (aHR, 1.15; 95% CI, 1.14-1.16), and then the HRs were no higher for those with a higher intake per session than 5 to 7 units (8-14 units per occasion: aHR, 1.11; 95% CI, 1.09-1.12; >14 units per occasion: aHR, 1.11; 95% CI, 1.08-1.14). Given similar weekly alcohol consumption levels, the risk of GI cancer increased with a higher frequency of drinking and decreased with a higher amount per occasion. Risk patterns for 6 specific cancers were generally similar to that of all GI cancers.

CONCLUSIONS AND RELEVANCE

In this cohort study, frequent drinking was a more important risk factor for incident GI cancers than the amount of alcohol consumed per occasion. Individuals should be cautioned about regular consumption of small amounts of alcohol in addition to the total amount of alcohol consumption or amount per occasion.

Risk factors and characteristics of young patients with the biliary tract carcinoma: results of a project study for biliary surgery by the Japanese Society of Hepato-Biliary-Pancreatic Surgery

PURPOSE

This study aimed to elucidate the characteristics of biliary tract carcinoma (BTC) in young patients.

METHODS

This is a nationwide multicenter, retrospective cohort study supervised by the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS). Clinicopathological data of patients aged <50 years diagnosed with BTC from January 1997 to December 2011 were collected from 211 training institutes for highly advanced surgery registered by the JHBPS.

RESULTS

Data of 774 young patients aged <50 years were obtained from 102 institutes. Pancreaticobiliary maljunction (PBM) (10.6%) was most frequently associated with young BTC. However, organic solvents caused by printing or other occupations were only 2.5%. PBM was further associated with early onset of BTC and was noted in 38.9% of patients aged <30 years. Subgroup analysis revealed that the distributions of PBM, choledochal cysts, cholelithiasis, hepatitis B virus, and past history of cancer were significantly varied depending on the site of BTC. These results suggested that each site of BTC has a different mechanism for cancer development.

CONCLUSION

Although the most frequent factor for young BTC patients was PBM, cancer-associated factors were dramatically different in each BTC site. These results might be useful to elucidate the etiology of young BTC patients.

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.

Relationship between Meat/Fish Consumption and Biliary Tract Cancer: The Japan Public Health Center-Based Prospective Study

BACKGROUND

The effect of meat and fish consumption on cancer risk has been well studied in humans. However, studies related to biliary tract cancer (BTC) are scarce.

METHODS

We examined the association between meat and fish consumption and the risk of BTC in a population-based prospective cohort study in Japan. HRs and 95% confidence intervals (CI) were estimated using the Cox proportional hazard model.

RESULTS

During 1995 and 1999, 43,177 men and 49,323 women ages 45 to 74 years were enrolled and followed up for 607,757.0 person-years (men) and 728,820.3 person-years (women) until 2012, during which time 217 male and 162 female BTC cases were identified. Higher total meat consumption was significantly associated with a decreased BTC risk in men (HR for the highest vs. lowest quartiles = 0.66; 95% CI, 0.44-0.98; P _trend = 0.011) but not in women. Similar association was observed with red meat, but no association was observed with poultry. Fish was not associated with BTC risk. We further analyzed each BTC subtype to confirm the observed association with BTC. However, significant association with each BTC subtype was not observed, although a trend of decreased extrahepatic bile duct cancer risk was observed.

CONCLUSIONS

BTC risk was lower among men who consumed more meat, particularly red meat, in Japan.

IMPACT

This is the first prospective study that evaluated the relationship between meat and BTC. This may provide important suggestions to elucidate the etiology of BTC.

Cholangiocarcinoma: Epidemiology and risk factors

Cholangiocarcinoma (CCA) is a heterogeneous disease arising from a complex interaction between host-specific genetic background and multiple risk factors. Globally, CCA incidence rates exhibit geographical variation, with much higher incidence in parts of the Eastern world compared to the West. These differences are likely to reflect differences in geographical risk factors as well as genetic determinants. Of note, over the past few decades, the incidence rates of CCA appear to change and subtypes of CCA appear to show distinct epidemiological trends. These trends need to be interpreted with caution given the issues of diagnosis, recording and coding of subtypes of CCA. Epidemiological evidences suggest that in general population some risk factors are less frequent but associated with a higher CCA risk, while others are more common but associated with a lower risk. Moreover, while some risk factors are shared by intrahepatic and both extrahepatic forms, others seem more specific for one of the two forms. Currently some pathological conditions have been clearly associated with CCA development, and other conditions are emerging; however, while their impact in increasing CCA risk as single etiological factors has been provided in many studies, less is known when two or more risk factors co-occur in the same patient. Moreover, despite the advancements in the knowledge of CCA aetiology, in Western countries about 50% of cases are still diagnosed without any identifiable risk factor. It is therefore conceivable that other still undefined etiologic factors are responsible for the recent increase of CCA (especially iCCA) incidence worldwide.