Pathology of Combined Hepatocellular Carcinoma-Cholangiocarcinoma: An Update

Other Primary Epithelial Neoplasms of the Liver

Primary liver carcinoma (PLC) is the sixth most common malignancy worldwide and the third leading cause of cancer-related mortalities. Hepatocellular carcinoma (HCC) is the most prevalent form of PLC, followed by intrahepatic cholangiocarcinoma (iCCA). In addition, there is a group of rarer PLCs that do not fit neatly into the HCC or iCCA categories. This review explores this heterogeneous group, including combined hepatocellular-cholangiocarcinoma (cHCC-CCA), intermediate cell carcinoma (ICC), mixed hepatocellular-neuroendocrine carcinoma, and undifferentiated primary liver carcinoma. cHCC-CCA is a rare subtype of PLC, characterized by both hepatocytic and cholangiocytic differentiation within the same tumor. The latest WHO classification (2019, fifth edition) redefined cHCC-CCA by eliminating the "stem cell subtypes" and emphasized that diagnosis should primarily rely on morphologic features, supported by immunohistochemical staining to better define subtypes. Intermediate cell carcinoma is a subtype of cHCC-CCA and is comprised of monomorphic tumor cells that exhibit characteristics intermediate between hepatocytes and cholangiocytes, with immunohistochemical expression of hepatocytic and cholangiocytic markers within the same cell. Another rare entity, combined HCC and neuroendocrine carcinoma (NEC), contains an admixture of HCC and NEC components within the same tumor. Undifferentiated primary liver carcinoma, on the other hand, lacks definitive lineage differentiation beyond an epithelial phenotype. These heterogeneous PLCs pose diagnostic challenges owing to their mixed/unusual histologic features and overlapping immunohistochemical markers. They tend to have poor prognoses, highlighting the critical importance of accurate and timely diagnosis.

Factors Contributing to the High Malignancy Level of Cholangiocarcinoma and Its Epidemiology: Literature Review and Data

CCA is a highly desmoplastic malignant cancer and is the second most common primary liver malignancy after hepatocellular carcinoma (HCC), accounting for approximately 15% of all primary liver tumors. CCA has a poor prognosis, with an average five-year survival rate of 9%, which is lower than that of pancreatic cancer. Although considerable efforts have been invested into the genomics, epigenetics, and risk factors, very little is known about what might have been the key causes for the high malignancy level of CCA. In this review, we analyze the incidence and mortality of CCA in different regions based on data from 1994 to 2022 obtained from the International Agency for Research on Cancer (IARC), discuss the current status of treatment of the disease, and focus on what might be the main factors contributing to the high malignancy level of CCA: alkalosis caused by the Fenton reaction, hypoxia, and the TIME. The review includes studies published from 1979 to 2024, aiming to provide an updated synthesis of basic early classical theoretical knowledge and current knowledge about CCA. By revealing the epidemiological characteristics of CCA, the potential mechanisms of high malignancy, and the current challenges of treatment, this review aims to provide new directions for future cancer research, promote the development of personalized treatment strategies, and facilitate a deeper understanding and the more effective management of CCA worldwide.

MRI features of combined hepatocellular-cholangiocarcinoma

Combined hepatocellular cholangiocarcinoma (cHCC-CCA) is a rare liver tumor which has a more aggressive behavior and worse survival outcome than hepatocellular carcinoma (HCC), with a prognosis similar to that of intrahepatic cholangiocarcinoma (iCCA). With limited literature on the appearance of this tumor on MRI, it remains a diagnostic challenge. In this review, we looked at the currently described MRI findings in this uncommon entity. Based on studies conducted to date, a mixed pattern at imaging has demonstrated the highest specificity, seen as a combination of areas showing progressive enhancement of the lesion, arterial enhancement with washout, and areas of arterial enhancement without washout and/or hypovascularity. Tumor markers may aid in identification, particularly in cases where the imaging appearance mimics that of isolated HCC or iCCA. Intratumoral heterogeneity leads to difficulties with pathologic diagnosis from sampling due to the possibility of an incorrect diagnosis if the biopsy specimen does not contain adequate tissue comprising both histologic components.

Prognostic Impact of CCA Components in Combined Hepatocellular Carcinoma-Cholangiocarcinoma

Purpose

To investigate the differences of combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) patients with a cholangiocarcinoma (CCA) component ≥ 30% or < 30% versus intrahepatic cholangiocarcinoma (iCCA) patients in recurrence-free survival (RFS) and overall survival (OS) prognoses.

Methods

Patients with cHCC-CCA and iCCA after surgery were recruited. All cHCC-CCA patients were divided into two subgroups (CCA components ≥ 30% and < 30%). Then, Kaplan-Meier survival analysis and Cox regression analysis were used to investigate and compare the differences of cHCC-CCAs with a CCA component ≥ 30% or < 30% versus iCCAs in RFS and OS prognoses, respectively. The differences of MRI features between cHCC-CCAs with a CCA component ≥ 30% and < 30% were also compared.

Results

One hundred sixty-four cHCC-CCAs and 146 iCCAs were enrolled. Compared with iCCAs, cHCC-CCAs with a CCA component < 30% had better OS prognosis (HR: 2.888, p = 0.045). However, Cox regression analysis revealed that cHCC-CCAs with a CCA component ≥ 30% had poorer RFS (HR: 0.503, p < 0.001) and OS (HR: 0.58, p = 0.033) prognoses than iCCAs. In addition, rim APHE (OR = 0.286, p < 0.001), targetoid diffusion restriction (OR = 0.316, p = 0.019), corona enhancement (OR = 0.481, p = 0.033), delayed enhancement (OR = 0.251, p = 0.001), and LR-M (OR = 1.586, p < 0.001) were significant factors associated with cHCC-CCAs with a CCA component ≥ 30%. Multivariable regression analyses showed that only LR-M (OR = 1.522, p = 0.042) was a significantly independent predictor for cHCC-CCAs with a CCA component ≥ 30%.

Conclusion

cHCC-CCAs with a CCA component ≥ 30% had worse prognoses than iCCAs. Therefore, we suggest that the postoperative treatment of cHCC-CCAs with a CCA component ≥ 30% can be based on the treatment strategy for iCCAs.

Systemic approaches in biliary tract cancers: a review in the era of multidirectional precision medicine

INTRODUCTION

Despite a rising incidence, biliary tract cancers (BTCs) are still considered a rare tumor entity. The disease's subtle clinical presentation and lack of effective early detection strategies often lead to a diagnosis at an advanced or unresectable stage, where curative options are limited.

AREAS COVERED

This review provides an overview of current systemic therapies and emerging novel approaches for BTC. For decades, the combination of gemcitabine with cisplatin (GemCis) has been the standard of care for palliative treatment. However, since 2020, the diagnostic and therapeutic landscape for BTC has evolved considerably, not only in the first-line setting but also beyond, driven by the development of clinical trials exploring immunotherapy and molecularly targeted agents. Due to the high frequency of targetable genetic alterations in BTC patients, there is a growing emphasis on obtaining tissue or liquid biopsy samples to identify markers like microsatellite instability and other actionable oncogenic driver genes.

EXPERT OPINION

Early initiation of systemic therapies in combination with multimodal approaches is essential for maximizing survival outcomes in patients with BTC.

Context-Dependent Distinct Roles of SOX9 in Combined Hepatocellular Carcinoma-Cholangiocarcinoma

Combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) is a challenging primary liver cancer subtype with limited treatment options and a devastating prognosis. Recent studies have underscored the context-dependent roles of SOX9 in liver cancer formation in a preventive manner. Here, we revealed that liver-specific developmental Sox9 elimination using Alb-Cre;Sox9(flox/flox) (LKO) and CRISPR/Cas9-based tumor-specific acute Sox9 elimination (CKO) in SB-HDTVI-based Akt-YAP1 (AY) and Akt-NRAS (AN) cHCC-CCA models showed contrasting responses. LKO abrogates the AY CCA region while stimulating poorly differentiated HCC proliferation, whereas CKO prevents AY and AN cHCC-CCA development irrespective of tumor cell fate. Additionally, AN, but not AY, tumor formation partially depends on the Sox9-Dnmt1 cascade. SOX9 is dispensable for AY-mediated, HC-derived, LPC-like immature CCA formation but is required for their maintenance and transformation into mature CCA. Therapeutic Sox9 elimination using the OPN-CreERT2 strain combined with inducible Sox9 iKO specifically reduces AY but not AN cHCC-CCA tumors. This necessitates the careful consideration of genetic liver cancer studies using developmental Cre and somatic mutants, particularly for genes involved in liver development. Our findings suggest that SOX9 elimination may hold promise as a therapeutic approach for a subset of cHCC-CCA and highlight the need for further investigation to translate these preclinical insights into personalized clinical applications.

Treatments and prognostic outcomes of combined hepatocellular-cholangiocarcinoma with distant metastasis: an analysis based on SEER data

Background

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare liver cancer with a poor prognosis, often diagnosed at an advanced stage. The management of cHCC-CCA with distant metastasis remains challenging, and prognostic factors are not well-defined. This study aimed to investigate prognostic factors and treatment outcomes for cHCC-CCA patients with distant metastasis.

Methods

Retrospective analysis was conducted using data from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database. Patients with distant metastasis [stage M1, according to the American Joint Committee on Cancer (AJCC) 7th edition] between January 2010 and December 2020 were included. Their characteristics, clinical profiles, and prognostic information were evaluated. Cox multifactorial survival analysis and Kaplan-Meier survival curves were used for statistical analysis.

Results

A total of 130 patients were included, with 78 (60%) receiving chemotherapy. Cox multivariate survival analysis revealed worse prognosis for Black individuals compared to White individuals (P<0.05). The median overall survival was 2 months for Black patients and 5 months for White patients. Chemotherapy significantly improved patient prognosis (P<0.05), while lung metastasis emerged as an independent risk factor (P<0.05). Kaplan-Meier survival curves confirmed the impact of lung metastasis and chemotherapy on overall survival. Patients with lung metastasis had lower survival rates (P<0.05), and those receiving chemotherapy had higher survival rates (P<0.05). Subgroup analysis based on age showed lower survival rates in patients aged 75 years or older compared to those below 75 years. Chemotherapy showed significant beneficial effects on the prognosis of patients below 75 years old, but no significant difference was observed in patients aged 75 years or above.

Conclusions

Chemotherapy improves the prognosis of cHCC-CCA patients with distant metastasis, especially for those under 75 years old. Black race and lung metastasis are poor prognostic factors.

Misdiagnosis Based on Neoplastic Markers-Extremely High Alpha-Fetoprotein in Patients with Intrahepatic Cholangiocarcinoma with Literature Review of the Published Cases

Background: Alpha-fetoprotein (AFP) and carbohydrate antigen 19-9 (CA 19-9) are two tumor markers that are widely used in the differential diagnosis in patients with primary liver tumors. Very high levels of AFP are sporadically observed in patients with intrahepatic cholangiocarcinoma (ICC) and may cause an incorrect initial diagnosis of hepatocellular carcinoma (HCC). Methods: Two cases of tumors in cirrhotic livers were described, in which the initial diagnosis, based on very high AFP levels (Patient I: 10,464 ng/mL, Patient II: 2212 ng/mL, reference range: ≤8.04 ng/mL) was HCC. In addition, the PubMed database was searched for cases of ICC with elevated AFP. Discussion: In both individuals, liver cirrhosis was diagnosed, but there was no typical rapid "washout" in the contrast-enhanced computed tomography. Based on the histological assessment of samples obtained in the core biopsies, the initially assumed diagnosis of HCC was changed to ICC in both cases. Only nine cases of patients with ICC and high AFP levels were found in the PubMed database. The AFP levels ranged from slightly elevated to over 16,000 ng/mL. Conclusions: A very high AFP level does not necessarily correlate with the presence of HCC. Therefore, the diagnosis has to be verified histologically, when the radiological imaging is uncertain in patients with liver cirrhosis.

Combined hepatocellular cholangiocarcinoma: A clinicopathological update

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer associated with an appalling prognosis. The diagnosis and management of this entity have been challenging to physicians, radiologists, surgeons, pathologists, and oncologists alike. The diagnostic and prognostic value of biomarkers such as the immunohistochemical expression of nestin, a progenitor cell marker, have been explored recently. With a better understanding of biology and the clinical course of cHCC-CCA, newer treatment modalities like immune checkpoint inhibitors are being tried to improve the survival of patients with this rare disease. In this review, we give an account of the recent developments in the pathology, diagnostic approach, and management of cHCC-CCA.

Therapeutic potential of SOX9 dysruption in Combined Hepatocellular Carcinoma-Cholangiocarcinoma

Combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) represents a challenging subtype of primary liver cancer with limited treatment options and a poor prognosis. Recently, we and others have highlighted the context-dependent roles of the biliary-specific transcription factor SOX9 in the pathogenesis of liver cancers using various Cre applications in Sox9 (flox/flox) strains, to achieve elimination for exon 2 and 3 of the Sox9 gene locus as a preventive manner. Here, we reveal the contrasting responses of developmental Sox9 elimination using Alb-Cre;Sox9 (flox/flox) ( Sox9 LKO) versus CRISPR/Cas9 -based tumor specific acute Sox9 CKO in SB-HDTVI-based Akt-YAP1 and Akt-NRAS cHCC-CCA formation. Sox9 LKO specifically abrogates the Akt-YAP1 CCA region while robustly stimulating the proliferation of remaining poorly differentiated HCC pertaining liver progenitor cell characteristics, whereas Sox9 CKO potently prevents Akt-YAP1 and Akt-NRAS cHCC-CCA development irrespective of fate of tumor cells compared to respective controls. Additionally, we find that Akt-NRAS , but not Akt-YAP1 , tumor formation is partially dependent on the Sox9-Dnmt1 cascade. Pathologically, SOX9 is indispensable for Akt-YAP1 -mediated HC-to-BEC/CCA reprogramming but required for the maintenance of CCA nodules. Lastly, therapeutic elimination of Sox9 using the OPN-CreERT2 strain combined with an inducible CRISPR/Cas9 -based Sox9 iKO significantly reduces Akt-YAP1 cHCC-CCA tumor burden, similar to Sox9 CKO. Thus, we contrast the outcomes of acute Sox9 deletion with developmental Sox9 knockout models, emphasizing the importance of considering adaptation mechanisms in therapeutic strategies. This necessitates the careful consideration of genetic liver cancer studies using developmental Cre and somatic mutant lines, particularly for genes involved in hepatic commitment during development. Our findings suggest that SOX9 elimination may hold promise as a therapeutic approach for cHCC-CCA and underscore the need for further investigation to translate these preclinical insights into clinical applications.

Combined hepatocellular-cholangiocarcinoma: from genesis to molecular pathways and therapeutic strategies

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most common primary liver cancers. Little is known about the combined hepatocellular-cholangiocarcinoma (cHCC-ICC) variant and the proper therapeutic strategies. Out of over 1200 available studies about cHCC-ICC, we selected the most representative ones that reflected updated information with application to individualized therapy. Based on literature data and own experience, we hypothesize that two molecular groups of cHCC-ICC can be identified. The proposed division might have a significant therapeutic role. Most cases develop, like HCC, on a background of cirrhosis and hepatitis and share characteristics with HCC; thus, they are named HCC-type cHCC-ICC and therapeutic strategies might be like those for HCC. This review also highlights a new carcinogenic perspective and identifies, based on literature data and the own experience, a second variant of cHCC-ICC called ICC-type cHCC-ICC. Contrary to HCC, these cases show a tendency for lymph node metastases and ICC components in the metastatic tissues. No guidelines have been established yet for such cases. Individualized therapy should be, however, oriented toward the immunoprofile of the primary tumor and metastatic cells, and different therapeutic strategies should be used in patients with HCC- versus ICC-type cHCC-ICC.

Current advances and future directions in combined hepatocellular and cholangiocarcinoma

The low incidence of combined hepatocellular cholangiocarcinoma (cHCC-CCA) is an important factor limiting research progression. Our study extensively included nearly three decades of relevant literature and assembled the most comprehensive database comprising 5,742 patients with cHCC-CCA. We summarized the characteristics, tumor markers, and clinical features of these patients. Additionally, we present the evolution of cHCC-CCA classification and explain the underlying rationale for these classification standards. We reviewed cHCC-CCA diagnostic advances using imaging features, tumor markers, and postoperative pathology, as well as treatment options such as surgical, adjuvant, and immune-targeted therapies. In addition, recent advances in more effective chemotherapeutic regimens and immune-targeted therapies were explored. Furthermore, we described the molecular mutation features and potential specific markers of cHCC-CCA. The prognostic value of Nestin has been proven, and we speculate that Nestin will also play a role in classification and diagnosis. However, further research is needed. Moreover, we believe that the possibility of using machine learning liquid biopsy for preoperative diagnosis and establishing a scoring system are directions for future research.

Transcription factor glucocorticoid modulatory element-binding protein 1 promotes hepatocellular carcinoma progression by activating Yes-associate protein 1

BACKGROUND

Glucocorticoid modulatory element-binding protein 1 (GMEB1), which has been identified as a transcription factor, is a protein widely expressed in various tissues. Reportedly, the dysregulation of GMEB1 is linked to the genesis and development of multiple cancers.

AIM

To explore GMEB1’s biological functions in hepatocellular carcinoma (HCC) and figuring out the molecular mechanism.

METHODS

GMEB1 expression in HCC tissues was analyzed employing the StarBase database. Immunohistochemical staining, Western blotting and quantitative real-time PCR were conducted to examine GMEB1 and Yes-associate protein 1 (YAP1) expression in HCC cells and tissues. Cell counting kit-8 assay, Transwell assay and flow cytometry were utilized to examine HCC cell proliferation, migration, invasion and apoptosis, respectively. The JASPAR database was employed for predicting the binding site of GMEB1 with YAP1 promoter. Dual-luciferase reporter gene assay and chromatin immunoprecipitation-qPCR were conducted to verify the binding relationship of GMEB1 with YAP1 promoter region.

RESULTS

GMEB1 was up-regulated in HCC cells and tissues, and GMEB1 expression was correlated to the tumor size and TNM stage of HCC patients. GMEB1 overexpression facilitated HCC cell multiplication, migration, and invasion, and suppressed the apoptosis, whereas GMEB1 knockdown had the opposite effects. GMEB1 bound to YAP1 promoter region and positively regulated YAP1 expression in HCC cells.

CONCLUSION

GMEB1 facilitates HCC malignant proliferation and metastasis by promoting the transcription of the YAP1 promoter region.