A Systematised Literature Review of Real-World Treatment Patterns and Outcomes in Unresectable Advanced or Metastatic Biliary Tract Cancer.

BACKGROUND: Biliary tract cancers are rare aggressive malignancies typically diagnosed when the disease is metastatic or unresectable, precluding curative treatment. OBJECTIVE: We aimed to identify treatment guidelines, real-world treatment patterns, and outcomes for unresectable advanced or metastatic biliary tract cancers in adult patients. METHODS: Databases (MEDLINE, Embase, Cochrane Database of Systematic Reviews) were systematically searched between 1 January, 2000 and 25 November, 2021, and supplemented by hand searches. Eligible records were (1) treatment guidelines and (2) observational studies reporting real-world treatment outcomes, for unresectable advanced or metastatic biliary tract cancers. Only studies performed in the UK, Germany, France, Australia, Canada and South Korea were extracted, to moderate the number of records for synthesis while maintaining representation of a wide range of biliary tract cancer incidences. RESULTS: A total of 66 relevant unique full-text records were extracted, including 16 treatment guidelines and 50 observational studies. Among guidelines, chemotherapies were most strongly recommended at first line (1L); the combination of gemcitabine and cisplatin (GEMCIS) was recommended as the standard of care in 1L. Recommendations for systemic chemotherapy in the second line (2L) conflicted because of uncertainties around survival benefit. Guidelines on further lines of treatment included a range of locoregional modalities and stenting or best supportive care without providing clear recommendations because of data paucity. Fifty observational studies reporting real-world treatment outcomes were extracted, of which 25 (50%) and 9 (18%) reported outcomes in 1L and 2L, respectively; 22 (44%) reported outcomes for treatments described as 'palliative'. In 1L, outcomes for systemic chemotherapy were most frequently described (23/25 studies), and GEMCIS was the most common systemic chemotherapy used (10/23 studies) in line with guidelines. Median overall survival with 1L systemic chemotherapy was < 12 months in most studies (16/23; range 4.7-22.3 months). Most 2L studies (10/11) described outcomes for systemic chemotherapy, most commonly for fluoropyrimidine-based regimen (5/10 studies). Median overall survival with 2L systemic chemotherapy was < 12 months in 5/10 studies (range 4.9-21.5 months). Median progression-free survival was reported more rarely than median overall survival. Some studies with small sample sizes or specifically selected patient populations (e.g. higher performance status, or patients who had already responded to treatment) achieved higher median overall survival. CONCLUSIONS: At the time of this review, treatment options for unresectable advanced or metastatic biliary tract cancers confer poor real-world survival. For over a decade, GEMCIS remained the 1L standard of care, highlighting the lack of therapeutic innovation in this indication and the urgent unmet need for novel treatments with improved outcomes in this aggressive condition. Additional observational studies are needed to further understand the effectiveness of currently available treatments, as well as newly available therapies including the addition of immunotherapy in the evolving treatment landscape.

Association of soft drinks and 100% fruit juice consumption with risk of cancer: a systematic review and dose-response meta-analysis of prospective cohort studies.

BACKGROUND: Studies of the associations between soft drinks and the risk of cancer showed inconsistent results. No previous published systematic reviews and meta-analysis has investigated a dose-response association between exposure dose and cancer risk or assessed the certainty of currently available evidence. Therefore, we aim to demonstrate the associations and assessed the certainty of the evidence to show our confidence in the associations. METHODS: We searched Embase, PubMed, Web of Science, and the Cochrane Library from inception to Jun 2022, to include relevant prospective cohort studies. We used a restricted cubic spline model to conduct a dose-response meta-analysis and calculated the absolute effect estimates to present the results. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of the evidence. RESULTS: Forty-two articles including on 37 cohorts enrolled 4,518,547 participants were included. With low certainty evidence, increased consumption of sugar-sweetened beverages (SSBs) per 250 mL/day was significantly associated with a 17% greater risk of breast cancer, a 10% greater risk of colorectal cancer, a 30% greater risk of biliary tract cancer, and a 10% greater risk of prostate cancer; increased consumption of artificially sweetened beverages (ASBs)re per 250 mL/day was significantly associated with a 16% greater risk of leukemia; increased consumption of 100% fruit juice per 250 mL/day was significantly associated with a 31% greater risk of overall cancer, 22% greater risk of melanoma, 2% greater risk of squamous cell carcinoma, and 29% greater risk of thyroid cancer. The associations with other specific cancer were no significant. We found linear dose-response associations between consumption of SSBs and the risk of breast and kidney cancer, and between consumption of ASBs and 100% fruit juices and the risk of pancreatic cancer. CONCLUSIONS: An increment in consumption of SSBs of 250 mL/day was positively associated with increased risk of breast, colorectal, and biliary tract cancer. Fruit juices consumption was also positively associated with the risk of overall cancer, thyroid cancer, and melanoma. The magnitude of absolute effects, however, was small and mainly based on low or very low certainty of evidence. The association of ASBs consumption with specific cancer risk was uncertain. TRIAL REGISTRATION: PROSPERO: CRD42020152223.

Confounded association between proton pump inhibitor use and risk of biliary tract cancer: Result from three cohorts.

Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.

Antitumour activity of neratinib in patients with HER2-mutant advanced biliary tract cancers.

HER2 mutations are infrequent genomic events in biliary tract cancers (BTCs). Neratinib, an irreversible, pan-HER, oral tyrosine kinase inhibitor, interferes with constitutive receptor kinase activation and has activity in HER2-mutant tumours. SUMMIT is an open-label, single-arm, multi-cohort, phase 2, 'basket' trial of neratinib in patients with solid tumours harbouring oncogenic HER2 somatic mutations (ClinicalTrials.gov: NCT01953926). The primary objective of the BTC cohort, which is now complete, is first objective response rate (ORR) to neratinib 240 mg orally daily. Secondary objectives include confirmed ORR, clinical benefit rate, progression-free survival, duration of response, overall survival, safety and tolerability. Genomic analyses were exploratory. Among 25 treatment-refractory patients (11 cholangiocarcinoma, 10 gallbladder, 4 ampullary cancers), the ORR is 16% (95% CI 4.5-36.1%). The most common HER2 mutations are S310F (n = 11; 48%) and V777L (n = 4; 17%). Outcomes appear worse for ampullary tumours or those with co-occurring oncogenic TP53 and CDKN2A alterations. Loss of amplified HER2 S310F and acquisition of multiple previously undetected oncogenic co-mutations are identified at progression in one responder. Diarrhoea is the most common adverse event, with any-grade diarrhoea in 14 patients (56%). Although neratinib demonstrates antitumour activity in patients with refractory BTC harbouring HER2 mutations, the primary endpoint was not met and combinations may be explored.

Evaluation of risk factors for chemotherapy-induced nausea and vomiting in cisplatin and gemcitabine treatment for biliary tract cancer: acid suppressants do not prevent nausea.

Chemotherapy-induced nausea and vomiting (CINV) is one of the most serious adverse effects of cancer therapy. Cancer patients frequently use acid suppressants (AS) for palliation of gastrointestinal symptoms associated with malignancy and/or anticancer therapy. AS are suggested as an additional option for CINV management in several antiemetic guidelines, although their efficacy remains unknown. The aim of this study was to determine whether AS administration affects CINV incidence in cisplatin and gemcitabine treatment for biliary tract cancer. The primary endpoint was to evaluate whether AS administration was associated with the incidence of all-grade nausea in the first administration by logistic analysis. The secondary endpoints were to assess factors associated with anorexia. Prophylactic antiemetics were based on current guidelines. Nausea occurred in 34.2% of patients (grade 1, 31.7%; grade 2, 2.5%). Patients exhibiting vomiting and anorexia represented 4.2% and 39.1%, respectively, without grade 3/4 symptoms. Multivariate analysis suggested that the independent risk factors for nausea as female sex, and no- or less-alcohol drinking habit and regular narcotics administration were associated with anorexia. In contrast, AS administration was not associated with nausea and anorexia incidence (odds ratio, 95% confidence interval: 1.43, 0.64-3.23; P =0.38 for nausea, 1.62, 0.71-3.68; P =0.25 for anorexia). In conclusion, we found that AS administration is not associated with CINV incidence, and female sex is a risk factor for nausea, and non-alcohol drinking habits and regular narcotic use are factors associated with anorexia in cisplatin and gemcitabine treatment for biliary tract cancer. We should correctly administer AS depending on the patient's situation. Successful CINV management needs effective monitoring and administration of prophylactic antiemetics and counter-measure medicines for patients at risk.

Exogenous estrogen and the risk of biliary tract cancer - a population-based study in a cohort of Swedish men treated for prostate cancer.

BACKGROUND: To assess the role of exogenous estrogen in the etiology of biliary tract cancer, a nationwide population-based cohort study in Sweden was performed. METHODS: The study included all men in Sweden with prostate cancer diagnosed in 1961-2008. Due to treatment standards, patients diagnosed in 1961-1980 were considered more exposed to estrogen, while those diagnosed in 1981-2008 were regarded less exposed. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated to estimate the risk of biliary tract cancer in cohort members compared to the corresponding Swedish male population. RESULTS: After 849 307 person-years of follow-up in 203 131 prostate cancer patients, there were 41 incident gallbladder cancers and 36 cancers of the extra-hepatic bile ducts. In overall, there were no apparent differences in the risk of gallbladder cancer or bile duct cancer between patients diagnosed in 1961-1980 and patients diagnosed in 1981-2008. However, in patients diagnosed in 1961-1980, there was a statistically non-significant increased risk of gallbladder cancer (SIR 1.34; 95% CI 0.71-2.29) and extra-hepatic bile duct cancer (SIR 1.20; 95% CI 0.55-2.28) > 5 years of follow-up after the prostate cancer diagnosis. No such association was found for patients diagnosed in 1981-2008. Sensitivity analyses excluding prostate cancer patients exposed to potential confounding factors did not change the SIRs. CONCLUSIONS: Long exposure to high doses of exogenous estrogen might increase the risk of biliary tract cancer. However, any potential excess risk of bile duct cancer resulted by prolonged exposure to high doses of exogenous estrogen seems to be small.

Neoplastic and nonneoplastic liver lesions induced by dimethylnitrosamine in Japanese medaka fish.

Small fish models have been used for decades in carcinogenicity testing. Demonstration of common morphological changes associated with specific mechanisms is a clear avenue by which data can be compared across divergent phyletic levels. Dimethylnitrosamine, used in rats to model human alcoholic cirrhosis and hepatic neoplasia, is also a potent hepatotoxin and carcinogen in fish. We recently reported some striking differences in the mutagenicity of DMN in lambda cII transgenic medaka fish vs. Big Blue(®) rats, but the pre-neoplastic and neoplastic commonalities between the two models are largely unknown. Here, we focus on these commonalities, with special emphasis on the TGF-ß pathway and its corresponding role in DMN-induced hepatic neoplasia. Similar to mammals, hepatocellular necrosis, regeneration, and dysplasia; hepatic stellate cell and "spindle cell" proliferation; hepatocellular and biliary carcinomas; and TGF-ß1 expression by dysplastic hepatocytes all occurred in DMN-exposed medaka. Positive TGF-ß1 staining increased with increasing DMN exposure in bile preductular epithelial cells, intermediate cells, immature hepatocytes and fewer mature hepatocytes. Muscle specific actin identified hepatic stellate cells in DMN-exposed fish. Additional mechanistic comparisons between animal models at different phyletic levels will continue to facilitate the interspecies extrapolations that are so critical to toxicological risk assessments.

Chemoprevention of chemically-induced biliary carcinogenesis in hamsters by vitamin K2.

BACKGROUND/AIMS: Pancreaticobiliary maljunction (PBM) is a high risk factor of biliary tract cancer. The chemopreventive effects of Vitamin K2 (menaquinone-4: MK4) in a hamster PBM model were investigated. METHODOLOGY: The extrahepatic bile duct at the distal end of the common duct was ligated and cholecystoduodenostomy was performed (Group I). The same surgery was performed and from 4 weeks after surgery, 10 mg/kg of N-nitrosobis (2-oxopropyl) amine was subcutaneously injected once a week with a one-week interval (Group II). In addition of Group II, MK4 was orally administered once a day, five times with every week (Group III). The hamsters were sacrificed 20 weeks after surgery and histopathological findings of gallbladder were investigated. RESULTS: Group I showed predominantly proper epithelium without cancer. In Group II, atypical epithelium (AE) was observed in 75% of animals and early cancer was observed in 25%. Group III showed less AE and no cancer. The PCNA labeling index in Group III was statistically significantly lower than in Group II. In addition, no statistically significant differences were noted among the groups in terms of the apoptosis labeling index. CONCLUSIONS: MK4 suppressed biliary carcinogenesis by the induction of cell cycle arrest in a hamster biliary carcinogenetic model.

Occupational exposure to pesticides and bile tract carcinoma in men: results from a European multicenter case-control study.

OBJECTIVES: To estimate the associations between occupational exposure to pesticides and extrahepatic biliary tract carcinoma in men, a population-based case-control study was carried out. METHODS: Cases (n = 104), aged 35-70, diagnosed in 1995-1997, were sampled by active reporting systems from hospitals. Controls (n = 1,401) were a random sample of the general male population. Information on occupation and confounding factors was obtained by questionnaires. Exposures were quantified with respect to time, application methods, and use of personal protective equipment. Intensity was evaluated by using a published algorithm which weighted the exposure assigned according to the use of personal protective equipment and mode of application. Logistic regression analyses were conducted adjusted for gallstones, age, and country. RESULTS: Being ever exposed to pesticides resulted in an odds ratio (OR) of 1.0 [95%-confidence interval (CI) 0.6-1.6]. A modestly elevated risk was found for backpack mounted sprayers OR = 1.4 [95% CI 0.7-2.6] and vine farmers OR = 2.5 [95% CI 0.9-7.2]. Using time periods and exposure frequency as intensity measure, no elevated risks were found. The only exception was year of maximum exposure which yielded an OR of 1.6 [95% CI 0.7-3.5]. However, no clear trend was observed in this analysis. CONCLUSIONS: This study does not rule out that pesticide exposure represents an occupational risk factor for extrahepatic biliary tract carcinoma, but no indication of a strong association was observed. Some modes of exposure were weakly, albeit not significantly associated with carcinoma risk. The observed estimates of effects may be influenced by a lack of precise exposure assessment. Different chemical compositions of pesticides were utilized during a long time span of pesticide exposure, and it should be considered that the exposure is assessed with substantial uncertainty that could non-differential and bias results toward the null.

Occupational exposure to endocrine-disrupting compounds and biliary tract cancer among men.

OBJECTIVES: This study investigated the association between cancer of the extrahepatic biliary tract and exposure to endocrine-disrupting compounds. METHODS: Altogether 183 men with histologically confirmed carcinoma of the extrahepatic biliary tract and 1938 matched controls were interviewed between 1995 and 1997 in the frame of an international multicenter case-control study in six European countries (Denmark, France, Germany, Italy, Spain, and Sweden). Self-reported job descriptions were converted to semiquantitative variables (intensity, probability, and duration of exposure) for 14 endocrine-disrupting compounds. The cases were compared with 1421 population controls and 517 colon adenocarcinoma patients. Odds ratios (OR) and 95% confidence intervals (95% CI) were obtained with unconditional logistic regression and adjusted for age, country, and gallstones. RESULTS: Occupational exposure to endocrine-disrupting compounds resulted in an OR of 1.4 (95% CI 1.0-2.1) with no dose-effect relationship for cumulative exposure (low: OR 1.3, 95% CI 0.6-3.0; medium: OR 1.5, 95% CI 0.8-2.7; high: OR 1.4, 95% CI 0.9-2.4) (only index participants). The elevated risk was restricted to extrahepatic bile ducts and ampulla Vateri (OR 1.7, 95% CI 1.0-2.6). The adjusted OR for cancer of the extrahepatic biliary tract after exposure to polychlorinated biphenyls was 2.8 (95% CI 1.3-5.9, only index participants). CONCLUSIONS: The data show some associations between exposure to endocrine-disrupting compounds in the workplace and the risk for cancer of the extrahepatic biliary tract among men, particularly for the extrahepatic bile duct and ampulla of Vater. Polychlorinated biphenyls could possibly be a strong risk factor.

Glycochenodeoxycholate plays a carcinogenic role in immortalized mouse cholangiocytes via oxidative DNA damage.

Bile acids have been suggested to be involved in biliary carcinogenesis, although the underlying mechanisms are yet to be established. The aim of this study was to investigate the carcinogenic effect of bile acids in the biliary tract in relation to oxidative stress. Immortalized mouse cholangiocytes were incubated with various bile acids, followed by measurement of reactive oxygen species (ROS) and the glutathione (GSH) level. As a marker of oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OHdG) expression in cholangiocytes was analyzed by flow cytometry. Then the expression of oxidative DNA repair enzymes in cholangiocytes was examined by real-time PCR. In addition, the long-term effect of bile acid-induced oxidative DNA damage on cholangiocytes was investigated using a mouse oligo DNA microarray. It was found that glycochenodeoxycholate (GCDC) induced the generation of ROS and the depletion of GSH. In contrast, no marked changes were induced by the other bile acids. The percentage of 8-OHdG-positive cells was also increased by GCDC, but the expression of oxidative DNA repair enzymes was not up-regulated. DNA microarray analysis showed marked changes of various genes associated with carcinogenesis (genes related to cell proliferation, angiogenesis, invasion, and metastasis). In conclusion, the long-term effect of oxidative DNA damage due to GCDC may promote carcinogenesis in the biliary tract. Furthermore, accumulation of 8-OHdG due to GCDC might contribute to the dysfunction of oxidative DNA repair enzymes.

Conference overview: molecular mechanisms of metal toxicity and carcinogenesis.

Chronic exposure to many heavy metals and metal-derivatives is associated with an increased risk of cancer, although the mechanisms of tumorigenesis are largely unknown. Approximately 125 scientists attended the 3rd Conference on Molecular Mechanisms of Metal Toxicity and Carcinogenesis and presented the latest research concerning these mechanisms. Major areas of focus included exposure assessment and biomarker identification, roles of ROS and antioxidants in carcinogenesis, mechanisms of metal-induced DNA damage, metal signalling, and the development of animal models for use in metal toxicology studies. Here we highlight some of the research presented, and summarize the conference proceedings.

Chemopreventative effect of a cyclooxygenase-2-specific inhibitor (etodolac) on chemically induced biliary carcinogenesis in hamsters.

The present study was designed to evaluate whether etodolac, a cyclooxgenase-2 (COX-2)-specific inhibitor, could prevent chemically induced biliary carcinogenesis in bilioenterostomized hamsters. Syrian golden hamsters were subjected to choledochojejunostomy and then received subcutaneous injections of N-nitrosobis(2-oxopropyl)amine (BOP) every 2 weeks at a dose of 10 mg/kg body wt. BOP administration was started 4 weeks after surgery, and continued for 18 weeks. The animals were simultaneously orally administered etodolac three times per week at a dose of 10 mg/kg body wt in 0.5% methylcellose solution (etodolac group). The control hamsters were administered methylcellose solution alone. The hamsters were killed 22 weeks after surgery, and the biliary carcinomas were evaluated histologically. The presence and degree of cholangitis and the cell kinetic status of the biliary epithelium were also evaluated with special reference to biliary carcinogenesis. Intrahepatic bile duct carcinomas developed in 15 of 17 (88%) hamsters in the control group, and in only six of 18 (33%) hamsters in the etodolac group (P < 0.01). The incidence and number of developing biliary carcinomas were well correlated with the degree of cholangitis, and severe cholangitis was evident in the controls. The cell kinetic study demonstrated that the proliferating cell nuclear antigen-labeling index of the biliary epithelium was 9.67 and 5.14% in the control and etodolac groups, respectively (P < 0.05). The mean levels of prostaglandin E(2) (PGE(2)) products in the liver tissue were 14.14 +/- 3.31 pg/total protein (TP) mg in the control group, and 7.46 +/- 2.34 pg/TP mg in the etodolac group (P < 0.05). These findings indicated that etodolac reduced both the occurrence of severe cholangitis and the acceleration of biliary epithelial cell kinetics after bilioenterostomy, resulting in the prevention of BOP-induced biliary carcinogenesis in hamsters. In conclusion, COX-2-specific inhibitor (etodolac) may be a possible agent against not only reflux cholangitis, but also biliary carcinoma after bilioenterostomy.

Inhibitory effect of loxiglumide (CR 1505), a cholecystokinin receptor antagonist, on N-nitrosobis(2-oxopropyl) amine-induced biliary carcinogenesis in Syrian hamsters.

We evaluated the cholecystokinin (CCK) receptor antagonist loxiglumide (CR1505) for a possible inhibitory effect on biliary carcinogenesis in a hamster model. Experimental group I underwent cholecystoduodenostomy and ligation of the distal end of the common bile duct, after which the animals were injected with N-nitrosobis(2-oxopropyl)amine (BOP) alone. Group II, after the same surgical procedure as in group I, were given injections of BOP and then given loxiglumide in their diet. The sham-operated group underwent simple laparotomy and then were given injections of BOP. Loxiglumide significantly inhibited BOP carcinogenicity in the gallbladder and extrahepatic bile duct but not in the intrahepatic bile ducts or pancreas. Autoradiography showed that loxiglumide significantly suppressed (125)I-Bolton-Hanter (BH)-CCK-8 binding to CCK receptors in the gallbladder and extrahepatic bile duct but not in the liver or pancreas, and CCK binding to its receptors was observed in an area identified as cancer tissue. CCK receptor antagonists have an inhibitory effect on BOP carcinogenesis in the extrahepatic biliary tract, including the gallbladder and extrahepatic bile duct, of Syrian hamsters. The difference in the inhibitory effect of loxiglumide on biliary carcinogenesis in hamsters according to site may be due to differences in CCK receptors or the affinity of loxiglumide for such biliary tract organs. A difference between carcinogenesis in the intrahepatic bile ducts and extrahepatic biliary tract may be another reason.

Historical cohort study of 10 109 men in the North American vinyl chloride industry, 1942-72: update of cancer mortality to 31 December 1995.

OBJECTIVES: To update and assess mortality from neoplasms to 31 December 1995 among 10 109 men employed in a job exposed to vinyl chloride for at least 1 year between 1942 and 1972 at any of 37 North American factories. Previous analyses indicated associations between employment in vinyl production and increased mortality risk from cancers of the liver and biliary tract, due to increased mortality from angiosarcoma of the liver, and brain cancer. METHODS: Standardised mortality ratio (SMR) analyses, overall and stratified by several work related variables, were conducted with United States and state reference rates. Cox's proportional hazards models and stratified log rank tests were used to further assess occupational factors. RESULTS: 895 of 3191 deaths (28%) were from malignant neoplasms, 505 since the previous update to the end of 1982. Mortality from all causes showed a deficit (SMR 83, 95% confidence interval (95% CI) 80 to 86), whereas mortality from all cancers combined was similar to state referent rates. Mortality from cancers of the liver and biliary tract was clearly increased (SMR 359, 95% CI 284 to 446). Modest excesses of brain cancer (SMR 142, 95% CI 100 to 197) and cancer of connective and soft tissue (SMR 270, 95% CI 139 to 472) were found. Stratified SMR and Cox's proportional hazard analyses supported associations with age at first exposure, duration of exposure, and year of first exposure for cancers of the liver and soft tissues, but not the brain. CONCLUSIONS: Excess mortality risk from cancer of the liver and biliary tract, largely due to angiosarcoma, continues. Risk of mortality from brain cancer has attenuated, but its relation with exposure to vinyl chloride remains unclear. A potentially work related excess of deaths from cancer of connective and soft tissue was found for the first time, but was based on few cancers of assorted histology.

Chemoprevention of biliary carcinogenesis in syrian hamsters by the novel carboxamide derivative IS-741 after initiation with N-nitrosobis(2-oxopropyl)amine (BOP).

To elucidate the possible inhibitory effect of a novel carboxamide derivative (IS-741) on biliary carcinogenesis, Syrian hamsters were subjected to cholecystoduodenostomy and ligation of the distal end of the common duct, and then given a regular diet (group I) or a diet containing 200 p.p.m. of IS-741 (group II). All hamsters were subcutaneously injected with N-nitrosobis(2-oxopropyl)amine until 10 weeks after surgery, and continued to feed on their respective dietary regimen until termination of the experiment at 16 weeks after surgery. Biliary adenocarcinomas were evaluated histologically. Non-cancerous and cancerous hepatobiliary tract tissues were analyzed for phospholipase A(2) (PLA(2)) activity, myeloperoxidase (MPO) activity, and the concentrations of prostaglandin (PG), i.e., prostaglandin E(2), 6-ketoprostaglandin F(1)alpha and thromboxane B(2). IS-741 significantly inhibited the development and multiplicity of hepatobiliary adenocarcinomas and reduced the proliferating cell nuclear antigen labeling indices in non-cancerous hepatobiliary tissues, compared with group I. The anti-cancerous effect of IS-741 was associated with a significant inhibition of PLA(2) and MPO levels in non-cancerous tissues of the extrahepatic biliary tract and the liver, and in cancerous tissue of the liver. Furthermore, IS-741 reduced the production of PGs in non-cancerous hepatobiliary tissues, compared with group I. Although the precise mechanism of action of IS-741 in preventing biliary tumorigenesis remains to be elucidated, it is likely to be related to modulation of arachidonic acid metabolism and/or suppression of neutrophil accumulation.

Tauroursodeoxycholate and cholestyramine enhance biliary carcinogenesis in hamsters.

The aim of this study was to examine whether tauroursodeoxycholate (TUDC) and cholestyramine resin (CR) enhance biliary carcinogenesis in the hamster model. A cholecystoduodenostomy with dissection of the extrahepatic bile duct on the distal end of the common duct was performed on Syrian hamsters. The hamsters were then divided randomly into 3 groups: control group, TUDC-treated group, and CR-treated group. All animals received N-nitrosobis(2-oxopropyl)amine (BOP) to initiate pancreaticobiliary cancer. The experiment was terminated at week 16 and the number of neoplastic lesions was counted microscopically. In the TUDC group, the intrahepatic biliary carcinogenesis was more accelerated than that observed in the control group, but no promoting effect was seen in the pancreas, gallbladder, or extrahepatic bile duct. In the CR group, both the intrahepatic biliary and the gallbladder carcinogenesis were inhibited compared with that observed in the control group and the TUDC group. TUDC enhanced the intrahepatic bile duct carcinogenesis, whereas CR inhibited both the intrahepatic bile duct and the gallbladder carcinoma. Bile acids were suggested to promote biliary carcinoma in the hamster model.

Organic solvents and cancer.

Epidemiologic evidence on the relationship between organic solvents and cancer is reviewed. In the 1980s, more than a million persons were potentially exposed to some specific solvents in the United States; in Canada, 40 percent of male cancer patients in Montreal had experienced exposure to solvents; in the Finnish population, one percent was regularly exposed. There is evidence for increased risks of cancer following exposure to: trichloroethylene (for the liver and biliary tract and for non-Hodgkin's lymphomas); tetrachloroethylene (for the esophagus and cervix--although confounding by smoking, alcohol, and sexual habits cannot be excluded--and non-Hodgkin's lymphoma); and carbon tetrachloride (lymphohematopoietic malignancies). An excess risk of liver and biliary tract cancers was suggested in the cohort with the high exposure to methylene chloride, but not found in the other cohorts where an excess risk of pancreatic cancer was suggested. 1,1,1-trichloroethane has been used widely, but only a few studies have been done suggesting a risk of multiple myeloma. A causal association between exposure to benzene and an increased risk of leukemia is well-established, as well as a suggested risk of lung and nasopharynx cancer in a Chinese cohort. Increased risks of various gastrointestinal cancers have been suggested following exposure to toluene. Two informative studies indicated an increased risk of lung cancer, not supported by other studies. Increased risks of lymphohematopoietic malignancies have been reported in some studies of persons exposed to toluene or xylene, but not in the two most informative studies on toluene. Occupation as a painter has consistently been associated with a 40 percent increased risk of lung cancer. (With the mixed exposures, however, it is not possible to identify the specific causative agent[s].) A large number of studies of workers exposed to styrene have evidenced no consistent excess risk of all lymphohematopoietic malignancies, although the most sensitive study suggested an excess risk of leukemia among workers with a high exposure.

Bilioenterostomy enhances biliary carcinogenesis in hamsters.

The aim of this study was to examine whether the type of bilioenterostomy enhances biliary carcinogenesis in the hamster model. Syrian hamsters were divided into the following groups; simple laparotomy (control group), cholecystoduodenostomy with dissection of the extrahepatic bile duct on the distal end of the common duct (CDDB group) and cholecystoileostomy with dissection of the extrahepatic bile duct on the distal end of the common duct (CIDB group). Following these procedures, all hamsters received N-nitrosobis(2-oxopropyl)amine. The diameter of the extrahepatic bile duct and plasma levels of cholecystokinin (CCK) were measured and the number of neoplastic lesions was counted microscopically. Proliferative effect of the procedures on the biliary epithelium was examined by proliferative cell nuclear antigen. In the CDDB group the extrahepatic bile duct was significantly dilated and carcinogenesis of the gall-bladder and extrahepatic bile ducts was enhanced. In the CIDB group the CCK bioactivity was stimulated and intrahepatic biliary duct, but not gall bladder and extrahepatic bile duct, carcinogenesis was promoted more than that observed in the CDDB group. Proliferation of the biliary duct epithelium was enhanced in both the CDDB and CIDB groups. Cholecystoduodenostomy enhanced intra- and extrahepatic bile duct carcinoma, whereas cholecystoileostomy promoted only intrahepatic bile duct carcinoma. Some factors in the intestinal juice seem to play a role in the promotion of biliary tract carcinoma.

Enhancement of biliary carcinogenesis in hamsters by cholecystokinin.

We recently developed a new model for rapid and reproducible induction of biliary carcinoma in hamsters. In the present study, we evaluated the effects of cholecystokinin (CCK), which has a trophic action on the gastrointestinal tract and on the pancreaticobiliary system, on biliary carcinogenesis in this hamster model. Hamsters treated with N-nitrosobis (2-oxopropyl) amine (BOP) were divided into four groups: In Group I, hydrolyzed gelatin, a solvent of CCK, was injected subcutaneously. In Groups II and III, CCK 2.5 and 25 microgram/kg were administered, respectively. In Group IV loxiglumide, a CCK receptor antagonist, was administered. CCK significantly promoted the carcinogenetic effect of BOP in the intra- and extrahepatic bile ducts but not in the gallbladder or pancreas. Loxiglumide exerted an inhibitory effect on carcinogenesis in the intrahepatic bile duct.