p53 status and its prognostic role in extrahepatic bile duct cancer: a meta-analysis of published studies

SERPINE1: Role in Cholangiocarcinoma Progression and a Therapeutic Target in the Desmoplastic Microenvironment

A heterogenous population of inflammatory elements, other immune and nonimmune cells and cancer-associated fibroblasts (CAFs) are evident in solid malignancies where they coexist with the growing tumor mass. In highly desmoplastic malignancies, CAFs are the prominent mesenchymal cell type in the tumor microenvironment (TME), where their presence and abundance signal a poor prognosis. CAFs play a major role in the progression of various cancers by remodeling the supporting stroma into a dense, fibrotic matrix while secreting factors that promote the maintenance of cancer stem-like characteristics, tumor cell survival, aggressive growth and metastasis and reduced sensitivity to chemotherapeutics. Tumors with high stromal fibrotic signatures are more likely to be associated with drug resistance and eventual relapse. Identifying the molecular underpinnings for such multidirectional crosstalk among the various normal and neoplastic cell types in the TME may provide new targets and novel opportunities for therapeutic intervention. This review highlights recent concepts regarding the complexity of CAF biology in cholangiocarcinoma, a highly desmoplastic cancer. The discussion focuses on CAF heterogeneity, functionality in drug resistance, contributions to a progressively fibrotic tumor stroma, the involved signaling pathways and the participating genes.

ARID1A Variations in Cholangiocarcinoma: Clinical Significances and Molecular Mechanisms

Cholangiocarcinoma (CCA), a high mortality malignant carcinoma characterized by advanced disease and frequent recurrence, constitutes a major challenge for treatment and prognosis. AT-rich interaction domain 1A (ARID1A) variation is a distinct genetic entity in CCA, getting mounting concerns recently. Here, we comprehensively reviewed the clinical significance and molecular mechanisms of ARID1A alterations in CCA. Based on the independent data derived from 29 relevant studies, the variation rate of ARID1A in intrahepatic and extrahepatic CCA is reported at 6.9-68.2% and 5-55%, respectively. Most of the included studies (28/29, 96.6%) suggest that ARID1A serves as a tumor suppressor in CCA. ARID1A variation may be an important prognostic indicator to predict disease mortality, metastasis, and recurrence in patients with CCA. Multifactorial molecular mechanisms are involved in the relationship between ARID1A variations and the pathogenesis and pathophysiology of CCA, including disruption of the cell cycle, chromatin remodeling, oxidative stress damage, DNA hypermethylation, and the interaction of multiple genes being affected. This review describes that ARID1A variation might be a potential diagnostic and prognostic biomarker for CCA. Future diagnoses and treatments targeting ARID1A hint towards a precision medicine strategy in the management of CCA.

Targeted therapies for extrahepatic cholangiocarcinoma: preclinical and clinical development and prospects for the clinic

Introduction: Until recently, cholangiocarcinoma (CCA) was a largely overlooked disease, and among CCAs, extrahepatic CCA (eCCA) was even more neglected. Despite the growing impact of molecularly targeted therapies and immunotherapy, prognosis of eCCA is dismal. Therefore, unraveling the complex molecular landscape of eCCA has become an urgent need. Deep phenotyping studies have revealed that eCCA is a heterogeneous tumor, harboring specific alterations categorizable into four classes, 'Mesenchymal', 'Proliferation', 'Immune', 'Metabolic'. Molecular alterations convey the activation of several pro-oncogenic pathways, where either actionable drivers or outcome predictors can be identified.Areas covered: We offer insights on perturbed pathways, molecular profiling, and actionable targets in eCCA and present a perspective on the potential stepping-stones to future progress. A systematic literature search in PubMed/ClinicalTrials.gov websites was performed by authors from different disciplines according to their specific topic knowledge to identify the newest and most relevant advances in precision medicine of eCCA.Expert opinion: eCCA is a distinct entity with unique features in terms of molecular classes, oncogenic drivers, and tumor microenvironment. Since more prevalent mutations are currently undruggable, and immunotherapy can be offered only to a minority of patients, international collaborations are instrumental to improve the understanding of the molecular underpins of this disease.

The pathways of genetic transformation in cholangiocarcinogenesis

Cholangiocarcinoma (CCA) is an aggressive malignancy that originates from the epithelial cells of the biliary duct system. Depending on the anatomical location, CCA can be considered extrahepatic (eCCA) or intrahepatic (iCCA) (1). Two thirds of CCAs involve the extrahepatic biliary system, whereas the rest are confined within the liver parenchyma, beyond the secondary biliary radicals (2). Due to its biological aggressiveness and difficulty in diagnosis, the majority of patients with CCA are unresectable at presentation and the overall 5-year survival is approximately five percent (4). This article focuses on the genetic and epigenetic alterations present in cholangiocarcinomas, their occasional relationship to external stimuli, and with an emphasis on those unanswered questions about cholangiocarcinogenesis and future directions in the comprehension of epigenetic DNA methylation in patients with CCA.

Genetic Abnormalities in Biliary Brush Samples for Distinguishing Cholangiocarcinoma from Benign Strictures in Primary Sclerosing Cholangitis

Background. Primary sclerosing cholangitis (PSC) is a chronic inflammatory liver disease and is strongly associated with cholangiocarcinoma (CCA). The lack of efficient diagnostic methods for CCA is a major problem. Testing for genetic abnormalities may increase the diagnostic value of cytology. Methods. We assessed genetic abnormalities for CDKN2A, TP53, ERBB2, 20q, MYC, and chromosomes 7 and 17 and measures of genetic clonal diversity in brush samples from 29 PSC patients with benign biliary strictures and 12 patients with sporadic CCA or PSC-associated CCA. Diagnostic performance of cytology alone and in combination with genetic markers was evaluated by sensitivity, specificity, and area under the curve analysis. Results. The presence of MYC gain and CDKN2A loss as well as a higher clonal diversity was significantly associated with malignancy. MYC gain increased the sensitivity of cytology from 50% to 83%. However, the specificity decreased from 97% to 76%. The diagnostic accuracy of the best performing measures of clonal diversity was similar to the combination of cytology and MYC. Adding CDKN2A loss to the panel had no additional benefit. Conclusion. Evaluation of MYC abnormalities and measures of clonal diversity in brush cytology specimens may be of clinical value in distinguishing CCA from benign biliary strictures in PSC.

Cholangiocarcinoma: from molecular biology to treatment

Cholangiocarcinoma is a rare tumor originating in the bile ducts, which, according to their anatomical location, is classified as intrahepatic, extrahepatic and hilar. Nevertheless, incidence rates have increased markedly in recent decades. With respect to tumor biology, several genetic alterations correlated with resistance to chemotherapy and radiotherapy have been identified. Here, we highlight changes in KRAS and TP53 genes that are normally associated with a more aggressive phenotype. Also IL-6 and some proteins of the BCL-2 family appear to be involved in the resistance that the cholangiocarcinoma presents toward conventional therapies. With regard to diagnosis, tumor markers most commonly used are CEA and CA 19-9, and although its use isolated appears controversial, their combined value has been increasingly advocated. In imaging terms, various methods are needed, such as abdominal ultrasound, computed tomography and cholangiopancreatography. Regarding therapy, surgical modalities are the only ones that offer chance of cure; however, due to late diagnosis, most patients cannot take advantage of them. Thus, the majority of patients are directed to other therapeutic modalities like chemotherapy, which, in this context, assumes a purely palliative role. Thus, it becomes urgent to investigate new therapeutic options for this highly aggressive type of tumor.

An Omics Perspective on Molecular Biomarkers for Diagnosis, Prognosis, and Therapeutics of Cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive biliary tract malignancy arising from the epithelial bile duct. The lack of early diagnostic biomarkers as well as therapeutic measures results in severe outcomes and poor prognosis. Thus, effective early diagnostic, prognostic, and therapeutic biomarkers are required to improve the prognosis and prolong survival rates in CCA patients. Recent advancement in omics technologies combined with the integrative experimental and clinical validations has provided an insight into the underlying mechanism of CCA initiation and progression as well as clues towards novel biomarkers. This work highlights the discovery and validation of molecular markers in CCA identified through omics approaches. The possible roles of these molecules in various cellular pathways, which render CCA carcinogenesis and progression, will also be discussed. This paper can serve as a reference point for further investigations to yield deeper understanding in the complex feature of this disease, potentially leading to better approaches for diagnosis, prognosis, and therapeutics.

Serum p53 Antibody Is Not Associated with p53 Immunoreactivity in Patients with Pancreatobiliary Cancers

Background. Recent diagnostic imaging tests contribute to improving the diagnosis of pancreatobiliary cancers. However, it is not practical to perform these tests for all patients as screening. Thus, less-invasive and simple screening tests are still required. A method to detect the IgG antibody induced in serum against the p53 protein accumulating due to p53 gene mutation, as a biomarker, was developed around 1990. Method. 35 patients with pancreatic cancer, 12 patients with biliary tract cancer, and 31 patients with benign pancreatobiliary diseases were entered into this study. Measurement of serum anti-p53 antibody was conducted in all patients. In addition, the rate of p53 protein overexpression was examined in those cases that could be examined pathologically. Result. Among all patients in the pancreatic cancer and biliary tract cancer groups, there was no patient with serum anti-p53 antibody positive value that exceeded the standard value. The rate of p53 protein overexpression was 48.0% in the patients with pancreatobiliary cancers and 0% in the benign pancreatobiliary diseases group. Conclusion. Serum anti-p53 antibody measurement does not contribute to the diagnosis of pancreatobiliary cancers. Instead, traditional p53 immunostaining still appears to be valuable in combination with standard procedures.

Radiotherapy prolongs biliary metal stent patency in malignant pancreatobiliary obstructions

Background/Aims

Biliary stenting is the most effective decompressive method for treating malignant biliary obstructive jaundice. Although the main cause of stent occlusion is tumor growth, few studies have investigated whether stent patency is affected by the combination of cancer-treatment modalities. The aim of this study was to evaluate the effects of local radiotherapy on metal-stent patency in patients with malignant biliary obstruction.

Methods

Patients who underwent self-expandable biliary metallic stenting for malignant biliary obstruction from 1999 to 2007 were included. Forty patients received chemotherapy and radiation therapy (radiation group, RG), and 31 patients received only chemotherapy (nonradiation group, NRG).

Results

The cumulative median stent patency was significantly longer in the RG than in the NRG (17.7 months; 95% confidence interval [CI], 1.8 to 33.6 months vs 8.7 months; 95% CI, 4.9 to 12.5 months; p=0.025). Stent occlusion caused by tumor growth or stent migration occurred in two (5%) and three (7.5%) cases in the RG and in six (19.3%) and two (6.5%) cases in the NRG, respectively.

Conclusions

The patency of biliary metal stents in pancreatobiliary cancer patients who receive chemoradiation therapy is significantly longer than that in patients who do not receive radiotherapy, which suggests that local cancer control significantly affects stent patency.

ERCC1 Can Be a Prognostic Factor in Hilar Cholangiocarcinoma and Extrahepatic Bile Duct Cancer, But Not in Intrahepatic Cholangiocarcinoma

PURPOSE

There are three types of bile duct cancer, intrahepatic cholangiocarcinoma (ICC), hilar cholangiocarcinoma (HC), and extrahepatic cholangiocarcinoma (EHC). Despite different clinical presentation, the same protocol has been used in treatment of patients with these cancers. We analyzed clinicopathologic findings and protein expression in order to investigate the difference and the specific prognostic factors among these three types of cancers.

MATERIALS AND METHODS

We conducted a retrospective review of 104 patients diagnosed with bile duct cancer at Seoul St. Mary's Hospital between January 1994 and May 2004. We performed immunohistochemical staining for p53, cyclin D1, thymidine phosphorylase, survivin, and excision repair cross-complementing group 1 (ERCC1).

RESULTS

Of the 104 patients, EHC was most common (44.2%). In pathologic findings, perineural invasion was significantly less common in ICC. Overall survival was similar among the three types of cancer. Lymph node invasion, lymphatic, and venous invasion showed a significant association with survival outcome in ICC, however, the differentiation of histologic grade had prognostic significance in HC and EHC. No difference in protein expression was observed among these types of cancer, however, ERCC1 showed a significant association with survival outcome in HC and EHC, not in ICC.

CONCLUSION

Based on our data, ICC showed different characteristics and prognostic factors, separate from the other two types of bile duct cancer. Conduct of further studies with a large sample size is required in order to confirm these data.

Modern diagnostic approaches to cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma is a very aggressive tumor with poor survival. Therefore, early diagnosis and surgical resection are of paramount importance. Its diagnosis is difficult because access to the tumor is not easy. Biopsy is possible only for intrahepatic cholangiocarcinoma, which accounts for 10% of cases. Routine brush cytology from endoscopic retrograde cholangiopancreatography (ERCP) has a high specificity of 100% but unfortunately a low sensitivity of 30%. In this review we briefly describe new diagnostic techniques applicable to ERCP brush cytology specimens and targeting the genetic background of the disease, in particular fluorescence in situ hybridization (FISH) and digital image analysis (DIA).

DATA SOURCES

The PubMed database up to 2011 was used for the retrieval of relevant articles. The search terms FISH, fluorescence in situ hybridization, DIA, digital image analysis and cholangiocarcinoma were used. Both original and review articles were used.

RESULTS

FISH identifies cells with chromosomal abnormalities, mainly numerical aberrations, using a mixture of fluorescence-labeled probes. FISH offers a higher sensitivity than routine cytology, retaining a high level of specificity. The DIA criterion for malignancy is demonstration of aneuploidy. This technique increases the sensitivity to 40%, but the specificity remains low. Preliminary data from application to other tumors suggest that combination of FISH and DIA may be of further benefit.

CONCLUSIONS

The new techniques offer a significantly enhanced diagnostic efficacy in the evaluation of ERCP brush specimens. Apart from contributing to a more timely diagnosis, their wider application to cholangiocarcinoma may also facilitate the genetic study of the disease and add to our understanding of oncogenesis at the molecular level, with the prospect of identifying targets for novel therapeutic interventions.