Cholangiocarcinoma - evolving concepts and therapeutic strategies

Cholangiocarcinoma is a disease entity comprising diverse epithelial tumours with features of cholangiocyte differentiation: cholangiocarcinomas are categorized according to anatomical location as intrahepatic (iCCA), perihilar (pCCA), or distal (dCCA). Each subtype has a distinct epidemiology, biology, prognosis, and strategy for clinical management. The incidence of cholangiocarcinoma, particularly iCCA, has increased globally over the past few decades. Surgical resection remains the mainstay of potentially curative treatment for all three disease subtypes, whereas liver transplantation after neoadjuvant chemoradiation is restricted to a subset of patients with early stage pCCA. For patients with advanced-stage or unresectable disease, locoregional and systemic chemotherapeutics are the primary treatment options. Improvements in external-beam radiation therapy have facilitated the treatment of cholangiocarcinoma. Moreover, advances in comprehensive whole-exome and transcriptome sequencing have defined the genetic landscape of each cholangiocarcinoma subtype. Accordingly, promising molecular targets for precision medicine have been identified, and are being evaluated in clinical trials, including those exploring immunotherapy. Biomarker-driven trials, in which patients are stratified according to anatomical cholangiocarcinoma subtype and genetic aberrations, will be essential in the development of targeted therapies. Targeting the rich tumour stroma of cholangiocarcinoma in conjunction with targeted therapies might also be useful. Herein, we review the evolving developments in the epidemiology, pathogenesis, and management of cholangiocarcinoma.

Cholangiocarcinoma. A spectrum of intrahepatic, perihilar, and distal tumors

OBJECTIVE

The objective of this article is to introduce a simple method for classifying cholangiocarcinomas and to apply this system to analyze a large number of patients from a single institution.

SUMMARY BACKGROUND DATA

For the past 2 decades, most western reports on cholangiocarcinoma have separated intrahepatic from extrahepatic tumors and have subclassified this latter group into proximal, middle, and distal subgroups. However, "middle" lesions are uncommon and are managed most often either with hilar resection or with pancreatoduodenectomy. The spectrum of cholangiocarcinoma, therefore, is best classified into three broad groups: 1) intrahepatic, 2) perihilar, and 3) distal tumors. These categories correlate with anatomic distribution and imply preferred treatment.

METHODS

The records of all patients with histologically confirmed cholangiocarcinoma who underwent surgical exploration at The Johns Hopkins Hospital over a 23-year period were reviewed.

RESULTS

Of 294 patients with cholangiocarcinoma, 18 (6%) had intrahepatic, 196 (67%) had perihilar, and 80 (27%) had distal tumors. Age, gender, race, and associated diseases were similar among the three groups. Patients with intrahepatic tumors, by definition, were less likely (p < 0.01) to be jaundiced and more likely (p < 0.05) to present with abdominal pain. The resectability rate increased with a more distal location (50% vs. 56% vs. 91%), and resection improved survival at each site. Five-year survival rates for resected intrahepatic, perihilar, and distal tumors were 44%, 11%, and 28%, and median survival rates were 26, 19, and 22 months, respectively. Postoperative radiation therapy did not improve survival. In a multivariate analysis resection (p < 0.001. hazard ratio 2.80), negative microscopic margins (p < 0.01, hazard ratio 1.79), preoperative serum albumin (p < 0.04, hazard ratio 0.82), and postoperative sepsis (p < 0.001, hard ratio 0.27) were the best predictors of outcome.

CONCLUSIONS

Cholangiocarcinoma is best classified into three broad categories. Resection remains the primary treatment, whereas postoperative adjuvant radiation has no influence on survival. Therefore, new agents or strategies to deliver adjuvant therapy are needed to improve survival.

Risk factors for cholangiocarcinoma

Cholangiocarcinoma (CC) is the second most common primary hepatic malignancy after hepatocellular cancer. CC accounts for approximately 10%-25% of all hepatobiliary malignancies. There are considerable geographic and demographic variations in the incidence of CC. There are several established risk factors for CC, including parasitic infections, primary sclerosing cholangitis, biliary-duct cysts, hepatolithiasis, and toxins. Other less-established potential risk factors include inflammatory bowel disease, hepatitis C virus, hepatitis B virus, cirrhosis, diabetes, obesity, alcohol drinking, tobacco smoking, and host genetic polymorphisms. In studies where the distinction between intra- and extrahepatic CC was used, some potential risk factors seem to have a differential effect on CC, depending on the site. Therefore, the consistent use of a more refined classification would allow a better understanding of risk factors for CC.

Cholangiocarcinoma: Epidemiology and risk factors

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

Integrative molecular analysis of intrahepatic cholangiocarcinoma reveals 2 classes that have different outcomes

BACKGROUND & AIMS

Cholangiocarcinoma, the second most common liver cancer, can be classified as intrahepatic cholangiocarcinoma (ICC) or extrahepatic cholangiocarcinoma. We performed an integrative genomic analysis of ICC samples from a large series of patients.

METHODS

We performed a gene expression profile, high-density single-nucleotide polymorphism array, and mutation analyses using formalin-fixed ICC samples from 149 patients. Associations with clinicopathologic traits and patient outcomes were examined for 119 cases. Class discovery was based on a non-negative matrix factorization algorithm and significant copy number variations were identified by Genomic Identification of Significant Targets in Cancer (GISTIC) analysis. Gene set enrichment analysis was used to identify signaling pathways activated in specific molecular classes of tumors, and to analyze their genomic overlap with hepatocellular carcinoma (HCC).

RESULTS

We identified 2 main biological classes of ICC. The inflammation class (38% of ICCs) is characterized by activation of inflammatory signaling pathways, overexpression of cytokines, and STAT3 activation. The proliferation class (62%) is characterized by activation of oncogenic signaling pathways (including RAS, mitogen-activated protein kinase, and MET), DNA amplifications at 11q13.2, deletions at 14q22.1, mutations in KRAS and BRAF, and gene expression signatures previously associated with poor outcomes for patients with HCC. Copy number variation-based clustering was able to refine these molecular groups further. We identified high-level amplifications in 5 regions, including 1p13 (9%) and 11q13.2 (4%), and several focal deletions, such as 9p21.3 (18%) and 14q22.1 (12% in coding regions for the SAV1 tumor suppressor). In a complementary approach, we identified a gene expression signature that was associated with reduced survival times of patients with ICC; this signature was enriched in the proliferation class (P < .001).

CONCLUSIONS

We used an integrative genomic analysis to identify 2 classes of ICC. The proliferation class has specific copy number alterations, activation of oncogenic pathways, and is associated with worse outcome. Different classes of ICC, based on molecular features, therefore might require different treatment approaches.

Intrahepatic cholangiocarcinoma: macroscopic type and stage classification

The Liver Cancer Study Group of Japan established a classification of macroscopic type and the TNM staging of intrahepatic cholangiocarcinoma (ICC). With the observation of more than 240 resected cases of ICC, three fundamental types were established. They were: (1) mass-forming (MF) type, (2) periductal-infiltrating (PI) type, and (3) intraductal growth (IG) type. The MF type forms a definite mass, located in the liver parenchyma. The PI type is defined as ICC which extends mainly longitudinally along the bile duct, often resulting in dilatation of the peripheral bile duct. The IG type proliferates toward the lumen of the bile duct papillarily or like a tumor thrombus. The TNM classification of ICC was then designed, using 136 cases of the MF type resected curatively between 1990 and 1996 at member institutes. Univariate and multivariate analyses showed: (1) tumor 2 cm or less, (2) single nodule, and (3) no vascular and serous membrane invasion as prognostic factors. T factors were defined as follows: T1 is an ICC that meets all requirements of factors (1), (2), and (3); T2 meets two of the three requirements, T3 meets one of the three requirements and T4 meets none of the three requirements. Our data did not support the idea that the hepatoduodenal lymph node is regional. The N factors were defined as N0 no lymph node metastasis; and N1, positive at any nodes. Thus, the stages of ICC were defined as stage I, T1N0M0; stage II, T2N0M0; stage III, T3N0M0; stage IVA, T4N0M0 or any TN1M0; and stage IVB, any T any NM1.

Genomic and Transcriptomic Profiling of Combined Hepatocellular and Intrahepatic Cholangiocarcinoma Reveals Distinct Molecular Subtypes

We performed genomic and transcriptomic sequencing of 133 combined hepatocellular and intrahepatic cholangiocarcinoma (cHCC-ICC) cases, including separate, combined, and mixed subtypes. Integrative comparison of cHCC-ICC with hepatocellular carcinoma and intrahepatic cholangiocarcinoma revealed that combined and mixed type cHCC-ICCs are distinct subtypes with different clinical and molecular features. Integrating laser microdissection, cancer cell fraction analysis, and single nucleus sequencing, we revealed both mono- and multiclonal origins in the separate type cHCC-ICCs, whereas combined and mixed type cHCC-ICCs were all monoclonal origin. Notably, cHCC-ICCs showed significantly higher expression of Nestin, suggesting Nestin may serve as a biomarker for diagnosing cHCC-ICC. Our results provide important biological and clinical insights into cHCC-ICC.

Liver resection for hilar and peripheral cholangiocarcinomas: a study of 62 cases

OBJECTIVE

To analyze a single center's 14-year experience with 62 consecutive patients with hilar (HCCA) and peripheral (PCCA) cholangiocarcinomas.

SUMMARY BACKGROUND DATA

Long-term survival after surgical treatment of HCCA and PCCA has been poor.

METHODS

From March 1981 until December 1994, 62 consecutive patients with HCCA (n = 28) and PCCA (n = 34) underwent surgical treatment. The operations were individualized and included local excision of the tumor and suprapancreatic bile duct, lymph node dissection, vascular reconstruction, and subtotal hepatectomy. Clinical and pathologic risk factors were examined for prognostic influence.

RESULTS

Patients were followed for a median of 25 months (12-102 months). Postoperative morbidity and mortality (at 30 days) were 32% and 14%, respectively, for HCCA and 24% and 6% for PCCA. The survival rates for HCCA and PCCA were 79% (+/-8%) and 67% (+/-8%) at 1 year; 39% (+/-10%) and 40% (+/-9%) at 3 years; and 8% (+/-7%) and 35% (+/-10%) at 5 years, respectively. The median survival was 24 (+/-4) months for HCCA and 19 (+/-8) months for PCCA. The disease-free survival rates for HCCA and PCCA were 85% (+/-10%) and 77% (+/-9%) at 1 year; 18% (+/-11%) and 41% (+/-12%) at 3 years; and 18% (+/-11%) and 41% (+/-12%) at 5 years, respectively. Nearly 80% of these patients had TNM stage IV tumors. With HCCA, no risk factors were associated with patient survival. For PCCA, multiple tumors (relative risk [RR] = 3.5; 95% confidence interval [CI] = 1.2-10.5) and incomplete resection (RR = 8.3; 95% CI = 2.3-29.6) were independently associated with a worse prognosis. For HCCA, there was a trend for lower disease-free survival in females (p = 0.056; log rank test). For PCCA, tumor size >5 cm was the only factor associated with disease recurrence (p = 0.024; log rank test).

CONCLUSIONS

Even though rare, 5-year survival by resection can be achieved in both HCCA and PCCA, but new adjuvant treatments are clearly needed.

Trends in survival after surgery for cholangiocarcinoma: a 30-year population-based SEER database analysis

The prognosis of patients with cholangiocarcinoma historically has been poor, even after surgical resection. Although data from some single-institution series indicate improvement over historical results, survival after surgical therapy for cholangiocarcinoma has not been investigated in a population-based study. We used the Surveillance, Epidemiology, and End Results database to identify patients who underwent surgery for cholangiocarcinoma from 1973 through 2002. Multivariate modeling of survival after surgery for intrahepatic cholangiocarcinoma showed an improvement in survival only within the last decade studied, resulting in a cumulative 34.4% improvement in survival from 1992 through 2002. In contrast, multivariate modeling of survival after surgery for extrahepatic cholangiocarcinoma revealed a 23.3% increase in adjusted survival per each decade studied, resulting in a cumulative 53.7% improvement from 1973 through 2002. We conclude that survival after surgery for extrahepatic cholangiocarcinoma has dramatically improved since 1973. Patients with intrahepatic cholangiocarcinoma, however, have achieved an improvement in survival largely confined to more recent years. We suggest that these trends are largely caused by developments in imaging technology, improvements in patient selection, and advances in surgical techniques.

Histopathology of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is currently the sixth most common type of cancer with a high mortality rate and an increasing incidence worldwide. Its etiology is usually linked to environmental, dietary or life-style factors. HCC most commonly arises in a cirrhotic liver but interestingly an increasing proportion of HCCs develop in the non-fibrotic or minimal fibrotic liver and a shift in the underlying etiology can be observed. Although this process is yet to be completely understood, this changing scenario also has impact on the material seen by pathologists, presenting them with new diagnostic dilemmas. Histopathologic criteria for diagnosing classical, progressed HCC are well established and known, but with an increase in detection of small and early HCCs due to routine screening programs, the diagnosis of these small lesions in core needle biopsies poses a difficult challenge. These lesions can be far more difficult to distinguish from one another than progressed HCC, which is usually a clear cut hematoxylin and eosin diagnosis. Furthermore lesions thought to derive from progenitor cells have recently been reclassified in the WHO. This review summarizes recent developments and tries to put new HCC biomarkers in context with the WHOs reclassification. Furthermore it also addresses the group of tumors known as combined hepatocellular-cholangiocellular carcinomas.

Multigene mutational profiling of cholangiocarcinomas identifies actionable molecular subgroups

One-hundred-fifty-three biliary cancers, including 70 intrahepatic cholangiocarcinomas (ICC), 57 extrahepatic cholangiocarcinomas (ECC) and 26 gallbladder carcinomas (GBC) were assessed for mutations in 56 genes using multigene next-generation sequencing. Expression of EGFR and mTOR pathway genes was investigated by immunohistochemistry. At least one mutated gene was observed in 118/153 (77%) cancers. The genes most frequently involved were KRAS (28%), TP53 (18%), ARID1A (12%), IDH1/2 (9%), PBRM1 (9%), BAP1 (7%), and PIK3CA (7%). IDH1/2 (p=0.0005) and BAP1 (p=0.0097) mutations were characteristic of ICC, while KRAS (p=0.0019) and TP53 (p=0.0019) were more frequent in ECC and GBC. Multivariate analysis identified tumour stage and TP53 mutations as independent predictors of survival. Alterations in chromatin remodeling genes (ARID1A, BAP1, PBRM1, SMARCB1) were seen in 31% of cases. Potentially actionable mutations were seen in 104/153 (68%) cancers: i) KRAS/NRAS/BRAF mutations were found in 34% of cancers; ii) mTOR pathway activation was documented by immunohistochemistry in 51% of cases and by mutations in mTOR pathway genes in 19% of cancers; iii) TGF-ß/Smad signaling was altered in 10.5% cancers; iv) mutations in tyrosine kinase receptors were found in 9% cases. Our study identified molecular subgroups of cholangiocarcinomas that can be explored for specific drug targeting in clinical trials.

Usefulness of 18F-FDG PET in intrahepatic cholangiocarcinoma

Surgical resection is the only curative treatment strategy for intrahepatic cholangiocarcinoma (CC). Therefore, accurate staging is essential for appropriate management of patients with CC. We assessed the usefulness of 2-[(18)F]fluoro-2-deoxy- d-glucose (FDG) positron emission tomography (PET) in the staging of CC. We undertook a retrospective review of FDG PET images in 21 patients (10 female, 11 male; mean age 57 years) diagnosed with CC. Ten patients had hilar CC and 11, peripheral CC. Patients underwent abdominal magnetic resonance imaging (MRI) ( n=20) and computed tomography (CT) ( n=12) for the evaluation of primary tumours, and chest radiography and whole-body bone scintigraphy for work-up of distant metastases. For semi-quantitative analysis, the maximum voxel standardised uptake value (SUV(max)) was obtained from the primary tumour. All peripheral CCs showed intensely increased FDG uptake, and some demonstrated ring-shaped uptake corresponding to peripheral rim enhancement on CT and/or MRI. In nine of the ten patients, hilar CCs demonstrated increased FDG uptake of a focal nodular or linear branching appearance. The remaining case was false negative on FDG PET. One patient with a false negative result on MRI demonstrated increased uptake on FDG PET. Among the ten hilar CCs, FDG uptake was intense in only two patients and was slightly higher than that of the hepatic parenchyma in the remaining patients. For the detection of lymph node metastasis, FDG PET and CT/MRI were concordant in 16 patients, and discordant in five (FDG PET was positive in three, and CT and MRI in two). FDG PET identified unsuspected distant metastases in four of the 21 patients; all of these patients had peripheral CC. FDG PET is useful in detecting the primary lesion in both hilar and peripheral CC and is of value in discovering unsuspected distant metastases in patients with peripheral CC. FDG PET could be useful in cases of suspected hilar CC with non-confirmatory biopsy and radiological findings.

Expression of MUC1 and MUC2 mucin antigens in intrahepatic bile duct tumors: its relationship with a new morphological classification of cholangiocarcinoma

Our previous immunohistochemical study on intrahepatic bile duct tumors showed that invasive cholangiocarcinoma (ICC) with a poor outcome expressed MUC1 mucin but was negative for MUC2 mucin, whereas bile duct cystadenocarcinoma (BDCC) with a favorable outcome was MUC1 negative and MUC2 positive. In the present study, ICC was further subdivided into 2 subtypes: intraductal growth type and/or periductal infiltrating type (ICC-IP) and mass forming type (ICC-M). The survival of patients with BDCC or ICC-IP is significantly better than that of patients with ICC-M. We examined these subtypes (ICC-IP and ICC-M) and BDCC for their expression of MUC1 mucins of different glycoforms. ICC-M showed significantly higher MUC1 expression rates (90%, 95%, and 85% positive rates as measured with the DF3, MY.1E12, and MUC1-Glycoprotein antibodies, respectively) than BDCC and ICC-IP (14% and 33%, 58% and 58%, and 0% and 50% positive respectively, as measured by the same antibodies). In contrast, BDCC (86% positive) and ICC-IP (67% positive) showed significantly higher MUC2 expression rates than ICC-M (25% positive) as measured with the anti-MRP antibody. Thus, the immunohistochemical staining pattern of ICC-IP resembled the pattern of BDCC more than they resembled ICC-M. In general, MUC1 expression is associated with poor patient outcome, irrespective of the glycosylation status. In particular, high expression of more sialylated forms of MUC1 mucins was correlated with poor survival. In contrast, expression of non-sialylated MUC2 mucin is a favorable prognostic indicator. These results suggest that ICC-IP is a different entity from ICC-M. This reclassification may have value in determining prognosis and treatment method.

Proposal of progression model for intrahepatic cholangiocarcinoma: clinicopathologic differences between hilar type and peripheral type

It is important to clarify the histologic progression of intrahepatic cholangiocarcinoma (ICC) in consideration of its origin from the intrahepatic large or small biliary ducts. On the basis of the gross and histologic assessment, we classified 87 cases of ICC smaller than 5 cm in diameter into hilar type (H-ICC, n=38) or peripheral type (P-ICC, n=49) to compare their clinical and histologic features. Biliary dysplasia was observed in 65.8% (25/38) of H-ICC cases, whereas hepatitis virus infection and liver cirrhosis were associated with 46.7% (21/45) and 28.6% (14/49) of P-ICC, respectively. The frequency of perineural invasion, lymph node metastasis, and extrahepatic recurrence of H-ICC was significantly higher than that of P-ICC (P<0.0001, 0.0106, and 0.0279, respectively). H-ICC cases showed frequent vascular invasion and intrahepatic metastasis even with small tumor size, compared with P-ICC cases. H-ICC showed large duct involvement within the tumor, and in the cases of large tumor size, intraductal spread was detected in the tumor periphery. P-ICC of small size contained preserved architecture of the portal tracts. The survival of patients with H-ICC was worse than that of patients with P-ICC (P=0.0121). The independent and best prognostic factor by multivariate analysis was intrahepatic metastasis for H-ICC and lymph node metastasis for P-ICC. Our results suggest that ICCs derived from a different level of biliary ducts were related to different premalignant conditions and different tumor progression. Some ICCs arising from the large biliary duct are likely to exhibit an aggressive course even in cases of small tumor size. The recognition of the above events induces the proper therapy.

Update on hepatocellular carcinoma: Pathologists’ review

Histopathologic diversity and several distinct histologic subtypes of hepatocellular carcinoma (HCC) are well-recognized. Recent advances in molecular pathology and growing knowledge about the biology associated with distinct histologic features and immuno-profile in HCC allowed pathologists to update classifications. Improving sub-classification will allow for more clinically relevant diagnoses and may allow for stratification into biologically meaningful subgroups. Therefore, immuno-histochemical and molecular testing are not only diagnostically useful, but also are being incorporated as crucial components in predicting prognosis of the patients with HCC. Possibilities of targeted therapy are being explored in HCC, and it will be important for pathologists to provide any data that may be valuable from a theranostic perspective. Herein, we review and provide updates regarding the pathologic sub-classification of HCC. Pathologic diagnostic approach and the role of biomarkers as prognosticators are reviewed. Further, the histopathology of four particular subtypes of HCC: Steatohepatitic, clear cell, fibrolamellar and scirrhous - and their clinical relevance, and the recent consensus on combined HCC-cholangiocarcinoma is summarized. Finally, emerging novel biomarkers and new approaches to HCC stratification are reviewed.

Depth of tumor invasion better predicts prognosis than the current American Joint Committee on Cancer T classification for distal bile duct carcinoma

BACKGROUND

The American Joint Committee on Cancer (AJCC) T classification system for cholangiocarcinoma does not take into account the unique pathologic features of the bile duct. As such, the current AJCC T classification for distal cholangiocarcinoma may be inaccurate.

METHODS

A total of 147 patients with distal cholangiocarcinoma were identified from a single institution database. The prognostic importance of depth of tumor invasion relative to the AJCC T classification system was assessed.

RESULTS

The AJCC T classification was T1 (n = 11, 7.5%), T2 (n = 6, 4.1%), T3 (n = 73, 49.7%), or T4 (n = 57, 38.8%). When cases were analyzed according to depth of tumor invasion, most lesions were > or =5 mm (<5 mm, 9.5%; range, 5-12, 51.0%; >12 mm, 39.5%). The AJCC T classification was not associated with survival outcome (median survival, T1, 40.1 months; T2, 14.8 months; T3, 16.5 months; T4, 20.2 months; P = .17). In contrast, depth of tumor invasion was associated with a worse outcome as tumor depth increased (median survival, <5 mm, not reached; range, 5-12, 28.9 months; >12 mm, 12.9 months; P = .001). On multivariate analyses, tumor depth remained the factor most associated with outcome (<5 mm; hazard ratio [HR] = referent vs 5-12 mm; HR = 3.8 vs >12 mm; HR = 6.7 mm; P = .001).

CONCLUSION

The AJCC T classification for distal cholangiocarcinoma does not accurately predict prognosis. Depth of the bile duct carcinoma invasion is a better alternative method to determine prognosis and should be incorporated into the pathologic assessment of resected distal cholangiocarcinoma.

Major hepatectomy for hilar cholangiocarcinoma type 3 and 4: prognostic factors and longterm outcomes

BACKGROUND

Radical operation for hilar cholangiocarcinoma, including major hepatectomy with vascular resection, seems to improve longterm survival. This study retrospectively evaluates several prognostic risk factors that can influence survival after resection of types 3 to 4 Klatskin tumors.

STUDY DESIGN

Between 1984 and 2003, 59 patients (36 men and 23 women) with types 3 to 4 hilar cholangiocarcinoma underwent liver resection with curative intent. Medical records and pathologic findings were reviewed to assess prognostic risk factors and survival. Disease-free and overall survival were analyzed using Kaplan-Meier and Cox proportional hazards models.

RESULTS

Survival rates at 1, 3, and 5 years were 82%, 45%, and 20% respectively. In-hospital mortality was 5% and morbidity was 42%. In multivariable analysis, male gender (relative risk [RR] = 5.4; 95% CI, 2.2 to 13.5), absence of preoperative chemotherapy (RR = 4; 95% CI, 1.5 to 10.7), R1 biliary tract margin (RR = 2.6; 95% CI, 1.1 to 4.4), and metastatic celiac lymph nodes (RR = 19.9; 95% CI, 4 to 71.4) were found to be independent factors for overall survival. Pedicular metastatic lymph nodes were not associated with poorer overall survival. If biliary positive-margin is the only risk factor, the 5-year estimated overall survival is 70%.

CONCLUSIONS

Major hepatectomy can improve outcomes of hilar cholangiocarcinoma. Compared with nonoperative treatment or R0 hepatectomy, R1 resection in patients with no other risk factor can offer longterm survival.

Cholangiocarcinoma: classification, diagnosis, staging, imaging features, and management

Cholangiocarcinoma is a relatively uncommon malignant neoplasm with poor prognosis. The distinction between extrahepatic and intrahepatic subtypes is important as epidemiological features, biologic and pathologic characteristics, and clinical course are different for both entities. This review study focuses on the role imaging plays in the diagnosis, classification, staging, and post-treatment assessment of cholangiocarcinoma.

Genetic classification of combined hepatocellular-cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma (combined HCC/ CC) is a rare form of liver neoplasms showing both hepatocellular (HCC) and bile duct differentiation (CC). In an attempt to clarify the clonality and genetic/phenotypic relationships in the evolution of these neoplasms, we microdissected multiple HCC and CC foci and studied allelic status of chromosome arms 1p, 1q, 3p, 4q, 5q, 6q, 8p, 9p, 10q, 11q, 13q, 16q, 17p, 17q, 18q, and 22q. Overall, the highest frequency of loss of heterozygosity (LOH) was seen on 4q and 17p, followed by 8p and 16q. Of the 11 cases studied, 3 cases did not show any of the identical allelic losses between HCC and CC foci, indicating the biclonal nature. The remaining 8 cases showed multiple allelic losses shared between both components, strongly suggestive of a single clonal derivation. Moreover, 4 of the 8 cases showed additional or divergent allelic losses at more than 1 chromosomal locus only in HCC and/or CC foci. Thus, this heterogeneity was shown to affect the phenotypic diversity of the tumor. Summarizing the genetic patterns, combined HCC/CC could be classified into the following 3 possibilities: (1) collision tumor in which 2 independent neoplastic clones develop at close proximity; (2) single clonal tumor with homogeneous genetic background in both components--histological diversity is thus a manifestation of divergent differentiation potential of a single clone; (3) single clonal process in which genetic heterogeneity in the process of clonal evolution within the tumor parallels histologic diversity; therefore, the tumor in this category is mainly composed of mosaics of closely related subclones.

Clinical and pathological features of Allen's type C classification of resected combined hepatocellular and cholangiocarcinoma: a comparative study with hepatocellular carcinoma and cholangiocellular carcinoma

The clinical features of Allen's type C of combined hepatocellular and cholangiocarcinoma (cHCC-CC) are not well known. In this study, we aim to define the clinicopathologic features of cHCC-CC and to evaluate the preoperative diagnosis and surgical treatment results in comparison with those of hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC). We retrospectively analyzed 13 patients with cHCC-CC, 509 patients with HCC, and 41 patients with CCC treated in our hospital within past two decades. Viral hepatitis B or C backgrounds were more prominent in HCC and cHCC-CC groups than in the CCC group. Elevated serum alpha-fetoprotein (AFP) levels were found in 60.3% of HCC patients and in 46.2% of cHCC-CC patients. Only one patient of cHCC-CC was correctly diagnosed before surgery. The postoperative survival rates between the cHCC-CC and HCC or the CCC group were not significantly different. Both intrahepatic and extrahepatic postoperative recurrences were frequent in cHCC-CC patients, and CCC component recurrences were more frequently seen. In conclusion, the preoperative diagnosis is difficult; liver masses similar to those of HCC, together with moderately elevated serum AFP and CA19-9 levels, are reliable indicators of cHCC-CC. Surgical resection of this tumor yields results intermediate between those of HCC and CCC in character. More cases are needed to further define the characteristics of this tumor.

Cholangiocarcinoma: Classification, Histopathology and Molecular Carcinogenesis

Cholangiocarcinoma (CC) is the second most common tumor of the liver, originating from the biliary system with increasing incidence and mortality worldwide. Several new classifications review the significance of tumor localization, site of origin, proliferation and biomarkers in the intrahepatic, perihilar and distal forms of the lesion. Based on growth pattern mass-forming, periductal-infiltrating, intraductal, undefined and mixed types are differentiated. There are further subclassifications which are applied for the histological features, in particular for intrahepatic CC. Recognition of the precursors and early lesions of CC including biliary intraepithelial neoplasia (BilIN), intraductal papillary neoplasm of the bile ducts (IPNB), biliary mucinous cystic neoplasm (MCNB) and the candidate precursors, such as bile duct adenoma and von Meyenburg complex is of increasing significance. In addition to the previously used biliary markers detected by immunohistochemistry, several new markers have been added to the differentiation of both the benign and malignant lesions, which can be used to aid in the subclassification in association with the outcome of CC. Major aspects of biliary carcinogenesis have been revealed, yet, the exact way of this diverse process is still unclear. The factors contributing to molecular cholangiocarcinogenesis include various risk factors, different anatomical localizations, multiple cellular origins, genetic and epigenetic alterations, tumor microenvironment, heterogeneity and clonal evolution. Driver mutations have been identified, implying that they are optimal candidates for targeted therapy. The most promising therapeutic candidates have entered clinical trials.

MR cholangiography versus cholangioscopy for evaluation of longitudinal extension of hilar cholangiocarcinoma

BACKGROUND

The utility of magnetic resonance cholangiography for assessment of longitudinal tumor extension of hilar cholangiocarcinoma was investigated with reference to findings by percutaneous transhepatic cholangioscopy.

METHODS

Ninety-nine patients with hilar cholangiocarcinoma underwent both magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy. Longitudinal tumor extension was described with the Bismuth-Corlette classification. Hilar cholangiocarcinoma was classified morphologically into stenotic, diffuse sclerosing, and polypoid types based on selective cholangiographic findings obtained during percutaneous transhepatic cholangioscopy. Agreement between percutaneous transhepatic cholangioscopy and magnetic resonance cholangiography according to the Bismuth-Corlette classification was compared. The degree of agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy according to each morphologic type was also compared in each subgroup without reference to Bismuth-Corlette type.

RESULTS

The overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy with regard to Bismuth-Corlette types was 87.9% (kappa = 0.832, p < 0.01). The agreement of magnetic resonance cholangiography for each Bismuth-Corlette type with reference to percutaneous transhepatic cholangioscopy was as follows: type I (n = 18), 16/18 (88.9%); type II (n = 16), 14/16 (87.5%); type IIIa (n = 23), 19/23 (82.6%); type IIIb (n = 14), 14/14 (100%); and type IV (n = 28), 24/28 (85.7%). The overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy for Bismuth-Corlette type according to selective cholangiographic findings was as follows: stenotic type, 58/61 (95.1%, kappa = 0.929, p < 0.01); diffuse sclerosing type, 12/16 (75%, kappa = 0.619, p < 0.01); and polypoid type, 17/22 (77.3%, kappa = 0.696, p < 0.01).

CONCLUSION

There is good overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy on longitudinal extension of hilar cholangiocarcinoma. Especially for the stenotic type of hilar cholangiocarcinoma (based on selective cholangiographic findings), magnetic resonance cholangiography may replace percutaneous transhepatic cholangioscopy in the determination of longitudinal tumor extension. For polypoid or diffuse sclerosing types, however, percutaneous transhepatic cholangioscopy is required for accurate evaluation of longitudinal tumor extension.

Cholangiographic spectrum of intraductal papillary mucinous neoplasm of the bile ducts

OBJECTIVE

To propose a cholangiographic classification for intraductal growth type intrahepatic cholangiocarcinoma (IG-ICC) and its precursor, collectively termed intraductal papillary mucinous neoplasm of the bile ducts (IPMN-B).

SUMMARY BACKGROUND DATA

For the extensive clinicopathologic variations of IPMN-B, a detailed characterization of cholangiography for IPMN-B is beneficial for determining the optimal therapeutic strategy.

METHODS

A total of 124 patients with cholangiography-available and pathologically proven IPMN-B were retrospectively studied. Numbers of IPMN-B type 1, type 2, type 3, and type 4 were 33, 17, 15, and 59, respectively. A cholangiographic classification was proposed based on the presence of hepatolithiasis, mucobilia, neoplasia localization, and concomitant malignancies. The demographics, histologic grading, management, and survival were also analyzed.

RESULTS

All 33 IPMN-B type 1 and 12 of 17 IPMN-B type 2 displayed cholangiographic pattern IA demonstrating hepatolithiasis-related biliary stricture. The remaining 5 IPMN-B type 2 displayed cholangiographic pattern IB or IC, which demonstrated mucobilia without discernible neoplasia. Seven of 15 IPMN-B type 3 and 52 of the 59 IPMN-B type 4 displayed cholangiographic pattern IIA or IIB, which demonstrated overt intraductal neoplasia. Seven IPMN-B type 3 or 4 displayed cholangiographic pattern IIIA or IIIB, which demonstrated IPMN-B and concomitant malignancies. For those presenting with cholangiographic pattern IA, IC, IIA, IIB, and IIIA, straightforward hepatectomies for the diseased lobes were performed. For those with pattern IB, surgical resections were performed only when there was emergence of mucin-producing neoplasia. For those with IIIB, the concomitant malignancies were considered inoperable. No disease-related death occurred in IPMN-B type 1and 2. The mean survival rates of IPMN-B type 3 and type 4 were 55.5 +/- 17.1 months and 36.9 +/- 6.3 months, respectively.

CONCLUSION

The presented cholangiographic classification facilitates the management for IPMN-B. Significant survival discrepancy at the various stages warrants a more aggressive surgical strategy.

Intrahepatic, perihilar and distal cholangiocarcinoma: Management and outcomes

 Introduction and aims. Cholangiocarcinomas are a heterogeneous group of tumors that can be classified into three clinically distinct types of cancers, intrahepatic, perihilar and distal cholangiocarcinoma. The inconsistent use of nomenclature for these cancers has obscured a true knowledge of the epidemiology, natural history and response to therapy of these cancers. Our aims were to define demographic characteristics, management and outcomes of these three distinct cancer types.

MATERIALS AND METHODS

A retrospective study of patients enrolled in an institutional cancer registry from 1992 to 2010. Median survival was compared between different treatment modalities over three time periods for the three types of cholangiocarcinoma at different stages of the disease using Kaplan Meyer analysis.

RESULTS

242 patients were identified. All cases were reviewed and classified into intrahepatic (90 patients), distal (48 patients) or perihilar (104 patients) cholangiocarcinomas. These cancers differed in median age of onset, gender distribution, median survival and stage. 13.8% of patients presented with stage I, 5.8% with stage II, 9.6% with stage III, 28% with stage IV, with 41.8% having unknown stage. The overall median survival was 15.8 months, and was 23, 25, 14, and 4.5 months for stages I, II, III, and IV respectively. Surgery improved survival in both early and advanced stages. Multimodality therapies further improved outcomes, particularly for perihilar cholangiocarcinoma.

CONCLUSION

Perihilar, distal and intrahepatic cholangiocarcinoma vary in their presentation, natural history and therapeutic approach to management. A consistently applied classification is essential for meaningful interpretation of studies of these cancers.