Cholangiocarcinoma: has there been any progress?

EZH2 as a potential therapeutic target for gastrointestinal cancers

Gastrointestinal (GI) cancers continue to be a major cause of mortality and morbidity globally. Understanding the molecular pathways associated with cancer progression and severity is essential for creating effective cancer treatments. In cancer research, there is a notable emphasis on Enhancer of zeste homolog 2 (EZH2), a key player in gene expression influenced by its irregular expression and capacity to attach to promoters and alter methylation status. This review explores the impact of EZH2 signaling on various GI cancers, such as colorectal, gastric, pancreatic, hepatocellular, esophageal, and cholangiocarcinoma. The primary function of EZH2 signaling is to facilitate the accelerated progression of cancer cells. Additionally, EZH2 has the capacity to modulate the reaction of GI cancers to chemotherapy and radiotherapy. Numerous pathways, including long non-coding RNAs and microRNAs, serve as upstream regulators of EZH2 in these types of cancer. EZH2's enzymatic activity enables it to attach to target gene promoters, resulting in methylation that modifies their expression. EZH2 could be considered as an independent prognostic factor, with increased expression correlating with a worse disease prognosis. Additionally, a range of gene therapies including small interfering RNA, and anti-tumor agents are being explored to target EZH2 for cancer treatment. This comprehensive review underscores the current insights into EZH2 signaling in gastrointestinal cancers and examines the prospect of therapies targeting EZH2 to enhance patient outcomes.

Transplant Oncology: An Emerging Discipline of Cancer Treatment

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The applications of oncology, transplant medicine, and surgery are the core of transplant oncology to improve patients' survival and quality of life. The main concept of transplant oncology is to radically cure cancer by removing the diseased organ and replacing it with a healthy one, aiming to improve the survival outcomes and quality of life of cancer patients. Subsequently, it seeks to expand the treatment options and research for hepatobiliary malignancies, which have seen significantly improved survival outcomes after the implementation of liver transplantation (LT). In the case of colorectal cancer (CRC) in the transplant setting, where the liver is the most common site of metastasis of patients who are considered to have unresectable disease, initial studies have shown improved survival for LT treatment compared to palliative therapy interventions. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years beyond Milan criteria in a stepwise manner. However, the outcome improvements and overall patient survival are limited to the specifics of the setting and systematic intervention options. This review aims to illustrate the representative concepts and history of transplant oncology as an emerging discipline for the management of hepatobiliary malignancies, in addition to other emerging concepts, such as the uses of immunotherapy in a peri-transplant setting as well as the use of circulating tumor DNA (ctDNA) for surveillance post-transplantation.

Surgery

This chapter provides a comprehensive background from basic to applied knowledge of surgical anatomy which is necessary for the surgical treatment of cholangiocarcinoma (CCA) patients. Significant advances that have been made in the surgical treatment of CCA were examined. For instance, in-depth details are provided for appropriate preoperative assessment and treatment to optimize patient status and to improve the outcome of surgical treatment(s). Comprehensive details are provided for the surgical techniques and outcomes of treatments for each type of CCA with clear illustrations and images. This chapter also describes the role of minimally invasive surgery and liver transplantation in CCA treatment.

Liver transplantation and intrahepatic cholangiocarcinoma: time to go forward again?

PURPOSE OF REVIEW

Liver transplantation for intrahepatic cholangiocarcinoma (iCCA) has been mired in controversy. High rates of recurrence posttransplant combined with donor organ scarcity resulted in most transplant centers treating iCCA as a contraindication for liver transplantation.

RECENT FINDINGS

Recent studies have shown that carefully selected patients with unresectable iCCA can have good outcomes after liver transplantation. Better outcomes have been seen in patients with smaller tumors and favorable tumor biology.

SUMMARY

Because many patients are diagnosed with iCCA at later stages, tumor biology and genetics are useful tools to identify patients who will have excellent overall and recurrence-free survival after liver transplantation. Further larger multicenter prospective studies are needed to identify patients who would benefit from liver transplantation with good outcomes. Additional advances will come through early diagnosis and utilizing a combination of chemotherapy and locoregional modalities as a bridge to transplant. There is also a need to recognize and develop additional neo- and adjuvant therapies for patients whose tumor biology currently precludes their inclusion on the liver transplantation waitlist.

Therapeutic targeting of ARID1A and PI3K/AKT pathway alterations in cholangiocarcinoma

BACKGROUND

Genetic alterations in ARID1A were detected at a high frequency in cholangiocarcinoma (CCA). Growing evidence indicates that the loss of ARID1A expression leads to activation of the PI3K/AKT pathway and increasing sensitivity of ARID1A-deficient cells for treatment with the PI3K/AKT inhibitor. Therefore, we investigated the association between genetic alterations of ARID1A and the PI3K/AKT pathway and evaluated the effect of AKT inhibition on ARID1A-deficient CCA cells.

METHODS

Alterations of ARID1A, PI3K/AKT pathway-related genes, clinicopathological data and overall survival of 795 CCA patients were retrieved from cBio Cancer Genomics Portal (cBioPortal) databases. The association between genetic alterations and clinical data were analyzed. The effect of the AKT inhibitor (MK-2206) on ARID1A-deficient CCA cell lines and stable ARID1A-knockdown cell lines was investigated. Cell viability, apoptosis, and expression of AKT signaling were analyzed using an MTT assay, flow cytometry, and Western blots, respectively.

RESULTS

The analysis of a total of 795 CCA samples revealed that ARID1A alterations significantly co-occurred with mutations of EPHA2 (p < 0.001), PIK3CA (p = 0.047), and LAMA1 (p = 0.024). Among the EPHA2 mutant CCA tumors, 82% of EPHA2 mutant tumors co-occurred with ARID1A truncating mutations. CCA tumors with ARID1A and EPHA2 mutations correlated with better survival compared to tumors with ARID1A mutations alone. We detected that 30% of patients with PIK3CA driver missense mutations harbored ARID1A-truncated mutations and 60% of LAMA1-mutated CCA co-occurred with truncating mutations of ARID1A. Interestingly, ARID1A-deficient CCA cell lines and ARID1A-knockdown CCA cells led to increased sensitivity to treatment with MK-2206 compared to the control. Treatment with MK-2206 induced apoptosis in ARID1A-knockdown KKU-213A and HUCCT1 cell lines and decreased the expression of pAKT^S473 and mTOR.

CONCLUSION

These findings suggest a dependency of ARID1A-deficient CCA tumors with the activation of the PI3K/AKT-pathway, and that they may be more vulnerable to selective AKT pathway inhibitors which can be used therapeutically.

Transplant Oncology: An Evolving Field in Cancer Care

Transplant oncology is an emerging concept of cancer treatment with a promising prospective outcome. The application of oncology, transplant medicine, and surgery to improve patients' survival and quality of life is the core of transplant oncology. Hepatobiliary malignancies have been treated by liver transplantation (LT) with significant improved outcome. In addition, as the liver is the most common site of metastasis for colorectal cancer (CRC), patients with CRC who have stable unresectable liver metastases are good candidates for LT, and initial studies have shown improved survival compared to palliative systemic therapy. The indications of LT for hepatobiliary malignancies have been slowly expanded over the years in a stepwise manner; however, they have only been shown to improve patient survival in the setting of limited systemic therapy options. This review illustrates the concept and history of transplant oncology as an evolving field for the management of hepatocellular carcinoma, intrahepatic biliary cancer, and liver-only metastasis of non-hepatobiliary carcinoma. The utility of immunotherapy in the transplant setting is discussed as well as the feasibility of using circulating tumor DNA for surveillance post-transplantation.

Development of a Theranostic Convergence Bioradiopharmaceutical for Immuno-PET Based Radioimmunotherapy of L1CAM in Cholangiocarcinoma Model

PURPOSE

Cholangiocarcinoma is a malignancy of bile duct with a poor prognosis. Conventional chemotherapy and radiotherapy are generally ineffective, and surgical resection is the only curative treatment for cholangiocarcinoma. L1-cell adhesion molecule (L1CAM) has been known as a novel prognostic marker and therapeutic target for cholangiocarcinoma. This study aimed to evaluate the feasibility of immuno-PET imaging-based radioimmunotherapy using radiolabeled anti-L1CAM antibody in cholangiocarcinoma xenograft model.

EXPERIMENTAL DESIGN

We prepared a theranostic convergence bioradiopharmaceutical using chimeric anti-L1CAM antibody (cA10-A3) conjugated with 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) chelator and labeled with ⁶⁴Cu or ¹⁷⁷Lu and evaluated the immuno-PET or SPECT/CT imaging and biodistribution with ⁶⁴Cu-/¹⁷⁷Lu-cA10-A3 in various cholangiocarcinoma xenograft models. Therapeutic efficacy and response monitoring were performed by ¹⁷⁷Lu-cA10-A3 and ¹⁸F-FDG-PET, respectively, and immunohistochemistry was done by TUNEL and Ki-67.

RESULTS

Radiolabeled cA10-A3 antibodies specifically recognized L1CAM in vitro, clearly visualized cholangiocarcinoma tumors in immuno-PET and SPECT/CT imaging, and differentiated the L1CAM expression level in cholangiocarcinoma xenograft models. ¹⁷⁷Lu-cA10-A3 (12.95 MBq/100 μg) showed statistically significant reduction in tumor volumes (P < 0.05) and decreased glucose metabolism (P < 0.01). IHC analysis revealed ¹⁷⁷Lu-cA10-A3 treatment increased TUNEL-positive and decreased Ki-67-positive cells, compared with saline, cA10-A3, or ¹⁷⁷Lu-isotype.

CONCLUSIONS

Anti-L1CAM immuno-PET imaging using ⁶⁴Cu-cA10-A3 could be translated into the clinic for characterizing the pharmacokinetics and selecting appropriate patients for radioimmunotherapy. Radioimmunotherapy using ¹⁷⁷Lu-cA10-A3 may provide survival benefit in L1CAM-expressing cholangiocarcinoma tumor. Theranostic convergence bioradiopharmaceutical strategy would be applied as imaging biomarker-based personalized medicine in L1CAM-expressing patients with cholangiocarcinoma.

Distinct histomorphological features are associated with IDH1 mutation in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma has known histological heterogeneity. Mutations in IDH1 (mIDH1) define a molecular subclass of intrahepatic cholangiocarcinoma and IDH-targeted therapies are in development. Characterizing mIDH1 ICC histomorphology is of clinical interest for efficient identification. Resected ICCs with targeted next-generation sequencing by MSK-IMPACT were selected. Clinical data were obtained. By slide review, blinded to IDH status, data were collected for histology type, mucin production, necrosis, fibrosis, cytoplasm cell shape (low cuboidal, plump cuboidal/polygonal, and columnar), and architectural pattern (anastomosing, tubular, compact tubular, and solid). A tumor was considered architecturally heterogeneous if no dominant pattern represented ≥75% of the tumor. Parameters were compared between mIDH1and IDH wild-type controls. In the examined cohort (113 ICC: 29 mIDH1 and 84 IDH wild-type), all IDH1-mutant tumors were of small duct-type histology, thus analysis was limited to 101 small duct-type tumors. mIDH1cases were more likely to have plump cuboidal/polygonal shape (P = .014) and geographic-type fibrosis (P = .005), while IDH1 wild-type were more likely to have low cuboidal shape (P = .005). Both groups were predominantly architecturally heterogeneous with no significant difference in the distribution of architectural patterns. Plump cuboidal/polygonal cell shape and a geographic-type pattern of intra-tumoral fibrosis are more often seen in mIDH1compared to IDH wild-type tumors; however, IDH1 mutation is not associated with a distinct histoarchitectural pattern.

RNAi screen reveals synthetic lethality between cyclin G-associated kinase and FBXW7 by inducing aberrant mitoses

Background:

F-box and WD40 repeat domain-containing 7 (FBXW7) is an E3 ubiquitin ligase involved in the ubiquitination and degradation of multiple oncogenic substrates. The tumour suppressor function is frequently lost in multiple cancers through genetic deletion and mutations in a broad range of tumours. Loss of FBXW7 functionality results in the stabilisation of multiple major oncoproteins, culminating in increased cellular proliferation and pro-survival pathways, cell cycle deregulation, chromosomal instability and altered metabolism. Currently, there is no therapy to specifically target FBXW7-deficient tumours.

Methods:

We performed a siRNA kinome screen to identify synthetically lethal hits to FBXW7 deficiency.

Results:

We identified and validated cyclin G-associated kinase (GAK) as a potential new therapeutic target. Combined loss of FBXW7 and GAK caused cell cycle defects, formation of multipolar mitoses and the induction of apoptosis. The synthetic lethal mechanism appears to be independent of clathrin-mediated receptor endocytosis function of GAK.

Conclusions:

These data suggest a putative therapeutic strategy for a large number of different types of human cancers with FBXW7 loss, many of which have a paucity of molecular abnormalities and treatment options.

The emerging role of endoscopic ultrasound for pancreaticobiliary diseases in the pediatric population

BACKGROUND

Endoscopic ultrasound (EUS) is a useful diagnostic and therapeutic tool in the pediatric population. Given the high accuracy and sensitivity of EUS, it is particularly effective in evaluating pancreaticobiliary disease. Published literature in the use of pediatric EUS is limited. Therefore we aimed to review the current literature for EUS indications, safety, and effectiveness for the pediatric population.

DATA SOURCES

English language articles on the use of pediatric endoscopic ultrasound in evaluating pancreaticobiliary diseases were retrieved from PubMed/ MEDLINE.

RESULTS

We analyzed various retrospective studies and case series publications. Data were extrapolated for pediatric patients with pancreaticobiliary diseases.

CONCLUSIONS

EUS offers superior imaging. It is comparible to magnetic resonance imaging and/or pancreatic-protocol computed tomography. In the current literature, there are a variety of pancreaticobiliary conditions where EUS was utilized to make a diagnosis. These include recurrent pancreatitis, congenital anomalies, microlithiasis, pancreatic pseudocysts, and pancreatic mass lesions. EUS was shown to be a safe and cost-effective modality with both diagnostic and therapeutic capabilities in the pediatric population. EUS is now increasingly being recognized as a standard of care when evaluating pancreaticobiliary conditions in children.

Proteomics profiling of cholangiocarcinoma exosomes: A potential role of oncogenic protein transferring in cancer progression

Cholangiocarcinoma (CCA), a common primary malignant tumor of bile duct epithelia, is highly prevalent in Asian countries and unresponsive to chemotherapeutic drugs. Thus, a newly recognized biological entity for early diagnosis and treatment is highly needed. Exosomes are small membrane bound vesicles found in body fluids and released by most cell types including cancer cells. The vesicles contain specific subset of proteins and nucleic acids corresponding to cell types and play essential roles in pathophysiological processes. The present study aimed to assess the protein profiles of CCA-derived exosomes and their potential roles. We have isolated exosomes from CCA cells namely KKU-M213 and KKU-100 derived from Thai patients and their roles were investigated by incubation with normal human cholangiocyte (H69) cells. Exosomes were internalized into H69 cells and had no effects on viability or proliferation of the host cells. Interestingly, the exosomes from KKU-M213 cells only induced migration and invasion of H69 cells. Proteomic analysis of the exosomes from KKU-M213 cells disclosed multiple cancer related proteins that are not present in H69 exosomes. Consistent with the protein profile, treatment with KKU-M213 exosomes induced β-catenin and reduced E-cadherin expressions in H69 cells. Collectively, our results suggest that a direct cell-to-cell transfer of oncogenic proteins via exosomal pathway may be a novel mechanism for CCA progression and metastasis.

Neoadjuvant therapy for downstaging of locally advanced hilar cholangiocarcinoma: a systematic review

BACKGROUND

Hilar cholangiocarcinoma is a rare but highly lethal type of cancer. A minority of patients present with resectable disease. Surgery remains the only treatment modality offering a chance of long-term survival. Unresectable patients are typically offered palliative treatment. The aim of this systematic review was to summarize the evidence for neoadjuvant therapy followed by surgical resection in patients presenting with hilar cholangiocarcinoma.

METHODS

Cochrane databases, Medline, PubMed and EMBASE were systematically searched to identify articles describing neoadjuvant therapy and surgical resection or re-assessment of resectability in patients with hilar cholangiocarcinoma. Included were all articles with original research. Study selection and data extraction were performed separately by two reviewers using a standardized protocol.

RESULTS

From 732 articles 8 full text articles and 2 abstracts met the inclusion criteria. The 2 abstracts and 1 full text article were case reports, 3 articles were retrospective and 4 were prospective studies (2 phase I and 2 phase II studies). Photodynamic therapy, chemotherapy and radiation therapy were used in various indications in populations that included patients with hilar cholangiocarcinoma, some of which were primarily unresectable. Overall quality of articles was limited.

CONCLUSION

Current evidence suggests that neoadjuvant therapy in patients with unresectable hilar cholangiocarcinoma can be performed safely and in a selected group of patients can lead to subsequent surgical R0 resection. Surgical resection of downstaged patients should be assessed in properly designed phase II studies.

Neoadjuvant chemoradiotherapy followed by liver transplantation for unresectable cholangiocarcinoma: a single-centre national experience

BACKGROUND

Unresectable cholangiocarcinoma (CCA) has a dismal prognosis. Initial studies of orthotopic liver transplantation (OLT) alone for CCA yielded disappointing outcomes. The Mayo Clinic demonstrated long-term survival using neoadjuvant chemoradiotherapy followed by OLT in selected patients with unresectable CCA. This study reports the Irish National Liver Transplant Programme experience of neoadjuvant therapy and OLT for unresectable CCA.

MATERIALS AND METHODS

Twenty-seven patients with CCA were selected for neoadjuvant chemoradiotherapy in a single centre from October 2004 to September 2011. Patients were given brachytherapy, external beam radiotherapy and 5-fluorouracil (5-Fu), followed by liver transplantation if progression free (20 patients).

RESULTS

Twenty progression-free patients after neoadjuvant therapy underwent OLT. Hospital mortality was 20%. Of the 16 patients who left hospital, survival rates were 94% and 61% at 1 and 4 years. Seven patients developed recurrent disease and died at intervals of 10-58 months after OLT, whereas 9 are disease free with a median follow-up of 37 months (18-76). Predictors of disease recurrence were a tumour in explant specimen and high CA 19.9 levels.

DISCUSSION

In selected patients with unresectable CCA, long-term survival can be achieved using neoadjuvant chemoradiotherapy and OLT although short-term mortality is high. Prospective international registries may aid patient selection and refinement of neoadjuvant regimens.

MYH rs3219476 and rs3219472 polymorphisms and risk of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a rare but devastating malignancy. Up to 90% of patients presenting with CCA have no identifiable risk factors. The base excision repair (BER) pathway has a principal role in the repair of mutations caused by oxidized or reduced bases. The MutY homolog (MUTYH, MYH) is one of the key proteins in the BER pathway, but the role of MYH in the tumorigenesis of CCA is largely unknown. In this study, we investigated the influence of MYH rs3219476 and rs3219472 polymorphisms on CCA incidence. MYH genotypes were detected using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. We found that for rs3219472, compared with subjects carrying the MYH G/G genotype, those with the A/A genotype had a 2.816-fold higher risk of CCA [odds ratio (OR)=2.816, 95% confidence interval (CI)=0.992-7.999, P=0.047). For rs3219476, compared with subjects carrying the MYH T/T genotype, those with the T/G genotype had a reduced risk of CCA (OR=0.359, 95% CI=0.17-0.758, P=0.006). Our findings suggest that since significantly increased CCA risk was found in individuals with a homozygous variant genotype for rs3219472, it may be a biomarker for screening individuals at high risk of developing the disease.

Novel multimodality treatment sequencing for extrahepatic (mid and distal) cholangiocarcinoma

Neoadjuvant chemoradiation has demonstrated significant advantages in the management of pancreatic adenocarcinoma. A similar tumor in a nearby anatomical location is extrahepatic cholangiocarcinoma, which has proven to be largely unresponsive to current forms of therapy. Neoadjuvant therapy for hilar cholangiocarcinoma has been combined with surgical resection and/or liver transplantation with a 25-33 % complete pathological response rate. We propose a wider application of neoadjuvant chemoradiation for patients with distal cholangiocarcinoma and present our rationale for this form of treatment sequencing.

Alteration of galectin-1 during tumorigenesis of Opisthorchis viverrini infection-induced cholangiocarcinoma and its correlation with clinicopathology

Galectin-1 is a beta-galactoside-binding lectin to function in cell adhesion, proliferation, differentiation, and might be involved in tumor progression and metastasis. In the present study, the expression kinetics of galectin-1 during the tumorigenesis of a parasite Opisthorchis viverrini infection-induced cholangiocarcinoma (CCA) was investigated in model animal hamsters, and the expression was confirmed in human CCA cases. It was found that galectin-1 was overexpressed at mRNA and protein levels with the tumor progression. The mRNA expression was elevated in very early stage during tumorigenesis and the increase was time dependent. Galectin-1 protein expression profiles indicated that the increased expression was mainly located in the epithelium of extensively proliferated and hyperplasia small bile ducts at early stage of CCA development in model animal and mainly in the extensive tumor stroma tissues in both model animals and human CCA cases at later stage. The analysis of correlation of the overexpression with clinicopathology in human cases suggested that high expression of galectin-1 was associated with advanced stage and metastasis and with shorter cumulative overall survival of the patients. Multivariate Cox regression analysis revealed that galectin-1 expression was of independent prognostic significance for CCA. Our results suggest that galectin-1 is likely involved in the tumorigenesis and expected to serve as a tumor stroma marker in diagnosis and prediction of metastasis and poor prognosis of the opisthorchiasis-associated CCA.

Efficacy and safety of liver transplantation in patients with cholangiocarcinoma: a systematic review and meta-analysis

The aim of our study was to evaluate the efficacy and safety of liver transplantation in patients with cholangiocarcinoma. According to the requirements of Cochrane systematic review, a thorough literature search was performed in PubMed/Medline, Embase and Cochrane electronic databases between 1995 and 2009 in terms of the key words "liver transplantation" and "cholangiocarcinoma," "cholangiocellular carcinoma" or "bile duct cancer," with restricted articles for the English language. Data were processed for a meta-analysis by Stata 10 software. Altogether 14 clinical trials containing 605 transplanted patients of bile duct cancers were finally enrolled in our study. The overall 1-, 3- and 5-year pooled survival rates were 0.73 [95% confidence interval (CI) = 0.65-0.80], 0.42 (95% CI = 0.33-0.51) and 0.39 (95% CI = 0.28-0.51), respectively. Of note, preoperative adjuvant therapies [orthotopic liver transplantation (OLT)-PAT group] rendered the transplanted individuals with comparably favorable outcomes with 1-, 3- and 5-year pooled survival rates of 0.83 (95% CI = 0.57-0.98), 0.57 (95% CI = 0.18-0.92) and 0.65 (95% CI = 0.40-0.87). In addition, the overall pooled incidence of complications was 0.62 (95% CI = 0.44-0.78), among which that of OLT-PAT group (0.58; 95% CI = 0.20-0.92) was relatively acceptable compared to those of liver transplantation alone (0.61; 95% CI = 0.33-0.85) and liver transplantation with extended bile duct resection (0.78; 95% CI = 0.55-0.94). In comparison to curative resection of cholangiocarcinoma with the 5-year survival rate reported from 20 to 40%, the role of liver transplantation alone is so limited. In the future, attention will be focused on liver transplantation following neoadjuvant radiochemotherapy, which requires a well-designed, prospective randomized controlled study.

Systematic review: management options for primary sclerosing cholangitis and its variant forms - IgG4-associated cholangitis and overlap with autoimmune hepatitis

BACKGROUND

Primary sclerosing cholangitis (PSC) remains a challenging disease to manage. The main goals are prevention of disease progression and reduction of the increased cancer risk.

AIMS

To review the management strategies for PSC and its variant forms based on published studies.

METHODS

Publications were identified using Pubmed, Medline and Ovid search engines.

RESULTS

Distinguishing PSC from variants, such as IgG4-associated cholangitis, and overlap with autoimmune hepatitis is essential to guide treatment decisions. There is no proven efficacious medical treatment for PSC. Ursodeoxycholic acid has been disappointing in low and moderate doses, and potentially dangerous in higher doses, although its role and optimal dose in chemoprevention requires investigation. The novel bile acid, 24-norursodeoxycholic acid, has shown promise in mouse models; human trials are in progress. Dominant strictures are optimally managed by dilatation and stenting to relieve obstructive complications, although exclusion of biliary malignancy is essential. Liver transplantation is the only proven therapy for those with advanced disease. Cholangiocarcinoma remains the most unpredictable and feared complication. In highly selected groups, neo-adjuvant chemoradiation with liver transplantation seems promising, but requires further validation. Screening for inflammatory bowel disease and surveillance for colorectal carcinoma should not be overlooked.

CONCLUSIONS

The effective management of PSC and its variants is hindered by uncertainties regarding pathogenesis of disease and factors responsible for its progression. Genome studies may help to identify further targets for drug therapy and factors leading to malignant transformation.

Molecular carcinogenesis of hepatocellular carcinoma and intrahepatic cholangiocarcinoma: one step closer to personalized medicine?

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the two major forms of primary liver cancers (PLC), accounting for approximately 90% and 5% respectively. The incidence of each is increasing rapidly in the western world, however our knowledge of the underlying mechanisms remains limited and the outcome, dismal. The etiologies of each vary geographically; nevertheless, chronic inflammation has been identified in more than 80% of the cases and appears to be a key mediator in altering the liver microenvironment, increasing the risk of carcinogenesis. However, since not all HCC and especially ICC cases have a recognized risk factor, there are currently two proposed models for liver carcinogenesis. The clonal evolution model demonstrates a multi-step process of tumor development from precancerous lesions to metastatic carcinoma, arising from the accumulation of genetic and epigenetic changes in a cell in the setting of chronic inflammation. While the majority of cases do occur as a consequence of chronic inflammation, most individuals with chronic infection do not develop PLC, suggesting the involvement of individual genetic and environmental factors. Further, since hepatocytes and cholangiocytes both have regenerative potential and arise from the same bi-potential progenitor cell, the more recently proposed cancer stem cell model is gaining its due attention. The integration of these models and the constant improvement in molecular profiling platforms is enabling a broader understanding of the mechanisms underlying these two devastating malignancies, perhaps moving us closer to a new world of molecularly-informed personalized medicine.

Molecular carcinogenesis of hepatocellular carcinoma and intrahepatic cholangiocarcinoma: one step closer to personalized medicine?

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the two major forms of primary liver cancers (PLC), accounting for approximately 90% and 5% respectively. The incidence of each is increasing rapidly in the western world, however our knowledge of the underlying mechanisms remains limited and the outcome, dismal. The etiologies of each vary geographically; nevertheless, chronic inflammation has been identified in more than 80% of the cases and appears to be a key mediator in altering the liver microenvironment, increasing the risk of carcinogenesis. However, since not all HCC and especially ICC cases have a recognized risk factor, there are currently two proposed models for liver carcinogenesis. The clonal evolution model demonstrates a multi-step process of tumor development from precancerous lesions to metastatic carcinoma, arising from the accumulation of genetic and epigenetic changes in a cell in the setting of chronic inflammation. While the majority of cases do occur as a consequence of chronic inflammation, most individuals with chronic infection do not develop PLC, suggesting the involvement of individual genetic and environmental factors. Further, since hepatocytes and cholangiocytes both have regenerative potential and arise from the same bi-potential progenitor cell, the more recently proposed cancer stem cell model is gaining its due attention. The integration of these models and the constant improvement in molecular profiling platforms is enabling a broader understanding of the mechanisms underlying these two devastating malignancies, perhaps moving us closer to a new world of molecularly-informed personalized medicine.