Gores, Gregory J.

The first objectives of this article are to review the structure, chemistry, and physiology of bile acids and the types of bile acid malabsorption observed in clinical practice. The second major theme addresses the classical or known properties of bile acids, such as the role of bile acid sequestration in the treatment of hyperlipidemia; the use of ursodeoxycholic acid in therapeutics, from traditional oriental medicine to being, until recently, the drug of choice in cholestatic liver diseases; and the potential for normalizing diverse bowel dysfunctions in irritable bowel syndrome, either by sequestering intraluminal bile acids for diarrhea or by delivering more bile acids to the colon to relieve constipation. The final objective addresses novel concepts and therapeutic opportunities such as the interaction of bile acids and the microbiome to control colonic infections, as in Clostridium difficile-associated colitis, and bile acid targeting of the farnesoid X receptor and G protein-coupled bile acid receptor 1 with consequent effects on energy expenditure, fat metabolism, and glycemic control.

Objectives: Brush cytology has a low sensitivity for the diagnosis of cholangiocarcinoma. This study aimed to compare the standard approach (brush cytology) with a triple modality approach utilizing brush cytology, forceps biopsy and fluorescence in situ hybridization in terms of sensitivity and specificity for the diagnosis of cholangiocarcinoma. Methods: In a retrospective study at a single academic center, 50 patients underwent triple modality testing. Additionally, 61 patients underwent brush cytology alone. Intervention was endoscopic retrograde cholangiopancreatography with brush cytology, fluorescence in situ hybridization, and forceps biopsy. The main outcome measures included sensitivity, specificity, positive predictive value and negative predictive value. Results: Overall, 50 patients underwent triple tissue sampling, and 61 patients underwent brush cytology alone. Twenty-two patients were eventually diagnosed with cholangiocarcinoma. Brush cytology had a sensitivity of 42%, specificity of 100%, positive predictive value of 100% and negative predictive value of 88%. Triple tissue sampling had an overall sensitivity of 82%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 87%. Within the triple test group, brush cytology had a sensitivity of 27%, forceps biopsy had a sensitivity of 50%, and fluorescence in situ hybridization analysis had a sensitivity of 59%. Conclusions: A triple modality approach results in a marked increase in sensitivity for the diagnosis of cholangiocarcinoma compared with single modality testing such as brush cytology and should be considered in the evaluation of indeterminate or suspicious biliary strictures.

Cholangiocarcinoma (CCA) is a lethal hepatobiliary neoplasm originating from the biliary apparatus. In humans, CCA risk factors include hepatobiliary inflammation and fibrosis. The recently identified interleukin (IL)−1 family member, IL‐33, has been shown to be a biliary mitogen which also promotes liver inflammation and fibrosis. Our aim was to generate a mouse model of CCA mimicking the human disease. Ectopic oncogene expression in the biliary tract was accomplished by the Sleeping Beauty transposon transfection system with transduction of constitutively active AKT (myr‐AKT) and Yes‐associated protein. Intrabiliary instillation of the transposon–transposase complex was coupled with lobar bile duct ligation in C57BL/6 mice, followed by administration of IL‐33 for 3 consecutive days. Tumors developed in 72% of the male mice receiving both oncogenes plus IL‐33 by 10 weeks but in only 20% of the male mice transduced with the oncogenes alone. Tumors expressed SOX9 and pancytokeratin (features of CCA) but were negative for HepPar1 (a marker of hepatocellular carcinoma). Substantive overlap with human CCA specimens was revealed by RNA profiling. Not only did IL‐33 induce IL‐6 expression by human cholangiocytes but it likely facilitated tumor development in vivo by an IL‐6–sensitive process as tumor development was significantly attenuated in Il‐6–/– male animals. Furthermore, tumor formation occurred at a similar rate when IL‐6 was substituted for IL‐33 in this model. Conclusion: The transposase‐mediated transduction of constitutively active AKT and Yes‐associated protein in the biliary epithelium coupled with lobar obstruction and IL‐33 administration results in the development of CCA with morphological and biochemical features of the human disease; this model highlights the role of inflammatory cytokines in CCA oncogenesis. (Hepatology 2015;61:1627–1642)

Transarterial chemoembolization (TACE) is a common treatment for patients with hepatocellular carcinoma (HCC) who are awaiting liver transplantation (LT). The aim of this study was to assess the impact of multiple TACE treatments on tumor necrosis, tumor recurrence, and survival in these patients. A retrospective analysis was performed for 104 consecutive patients undergoing LT for HCC from January 2002 to December 2009 who were treated with TACE before LT. The number of TACE treatments was not associated with tumor necrosis in the explant. After a median follow‐up of 69 months (range = 0‐123 months), 14 of the 104 patients (13%) developed recurrent HCC after LT. Recurrence had a significant relationship with a short interval between the diagnosis of HCC and LT (≤6 months) in univariate and multivariate analyses [P = 0.029, odds ratio (OR) = 19.2]. Patients subjected to a single TACE treatment were more likely to experience recurrence, although this finding was not confirmed in the multivariate analysis. No significant relationship was observed between tumor necrosis in the explant and recurrence. The mean overall survival was 102.8 months (95% confidence interval = 94.9‐110.8 months) with 1‐, 3‐, and 5‐year survival rates of 91%, 89%, and 84% respectively. In the univariate survival analysis, the presence of ascites before TACE, a waiting time ≤ 9 months, and tumor characteristics at the pathological examination were statistically associated with shorter survival. In the multivariate analysis, only vascular invasion (P < 0.001, OR = 7.99) remained independently associated with shorter survival. The number of TACE treatments was not associated with survival. In conclusion, multiple TACE treatments were not associated with a higher risk of recurrence or shorter survival. Continued use of TACE should be considered as indicated if the patient and lesions are suitable for retreatment. A shorter waiting time before LT is related to an increased risk of recurrence and decreased survival after LT for HCC. These data could reflect the presence of more aggressive tumor biology and may be useful for guiding organ allocation policy to consider a minimum observation period before LT for regions with shorter wait times. Liver Transpl 21:248‐257, 2015. © 2014 AASLD.

AbstractCholangiocarcinoma (CCA) is an aggressive biliary tract malignancy with limited treatment options and low survival rates. Currently, there are no curative medical therapies for CCA. Recent advances have enhanced our understanding of the genetic basis of this disease, and elucidated therapeutically relevant targets. Therapeutic efforts in development are directed at several key pathways due to genetic aberrations including receptor tyrosine kinase pathways, mutant IDH enzymes, the PI3K-AKT-mTOR pathway, and chromatin remodeling networks. A highly desmoplastic, hypovascular stroma is characteristic of CCAs and recent work has highlighted the importance of targeting this pathway via stromal myofibroblast depletion. Future efforts should concentrate on combination therapies with action against the cancer cell and the surrounding tumor stroma. As the mutational landscape of CCA is being illuminated, molecular profiling of patient tumors will enable identification of specific mutations and the opportunity to offer directed, personalized treatment options.