The clinicopathological and prognostic relevance of cytokeratin 7 and 19 expression in hepatocellular carcinoma. A possible progenitor cell origin

Proliferative hepatocellular carcinomas in cirrhosis: patient outcomes of LI-RADS category 4/5 and category M

OBJECTIVES

We aimed to compare Liver Imaging Reporting and Data System (LI-RADS) category 4/5 and category M (LR-M) of proliferative hepatocellular carcinomas (HCCs) in cirrhotic patients and evaluate their impacts on prognosis.

METHODS

This retrospective multi-reader study included cirrhotic patients with single treatment-naïve HCC ≤ 5.0 cm who underwent contrast-enhanced CT, MRI, and subsequent hepatic resection within 2 months. The percentages of CT/MRI LR-4/5 and LR-M in proliferative and non-proliferative HCCs were compared. Univariable and multivariable Cox proportional hazards regression analyses were performed to assess the association of LI-RADS categories (LR-4/5 vs. LR-M) and pathologic classification (proliferative vs. non-proliferative) with overall survival (OS) and recurrence-free survival (RFS). Subgroups of patients with proliferative and non-proliferative HCCs were analyzed to compare OS and RFS between LR-4/5 and LR-M.

RESULTS

Of the 204 included patients, 38 were classified as having proliferative HCC. The percentages of LR-M were higher in proliferative than non-proliferative HCC on both CT (15.8% vs. 3.0%, p = 0.007) and MRI (26.3% vs. 9.6%, p = 0.016). Independent of pathologic classification, CT and MRI LR-M were significantly associated with poorer OS (hazard ratio (HR) = 4.58, p = 0.013, and HR = 6.45, p < 0.001) and RFS (HR = 3.66, p = 0.005, and HR = 6.44, p < 0.001) than LR-4/5. MRI LR-M was associated with significantly poorer OS (p ≤ 0.003) and RFS (p < 0.001) than MRI LR-4/5 in both proliferative and non-proliferative HCCs.

CONCLUSIONS

This multi-reader study showed that the percentages of LR-M were significantly higher in proliferative than non-proliferative HCCs. CT/MRI LR-M was significantly associated with poor OS and RFS, independent of the pathologic classification of proliferative versus non-proliferative HCCs.

CLINICAL RELEVANCE STATEMENT

CT and MRI LI-RADS category M can be clinically useful in predicting poor outcomes in patients with proliferative and non-proliferative hepatocellular carcinomas.

KEY POINTS

• The percentages of LR-M tumors on both CT and MRI were significantly higher in proliferative than non-proliferative hepatocellular carcinomas. • Independent of pathologic classification, CT/MRI LR-M categories were correlated with poor overall survival and recurrence-free survival. • Patients with both proliferative and non-proliferative hepatocellular carcinomas categorized as MRI LR-M had significantly poorer overall survival and recurrence-free survival than those categorized as MRI LR-4/5.

Analysis of clinicopathologic and imaging features of dual-phenotype hepatocellular carcinoma

Dual-phenotype hepatocellular carcinoma (DPHCC) is a new subtype of hepatocellular carcinoma (HCC). This study aimed to investigate the relationship between the computerized tomography scan (CT) imaging and clinicopathologic features of DPHCC. The CT imaging and clinicopathologic data of 97 HCC cases who underwent radical resection were collected retrospectively. The CT imaging feature was evaluated by the ratio of the average CT value of tumor to liver (TLR) in the plain scan, arterial, portal vein and delayed phases. The association between CT imaging and clinicopathologic features was analyzed using the t-test or chi-square test. Univariate and multivariate recurrence-free survival (RFS) analysis and overall survival (OS) were performed. The positive rates of cytokeratin 7 (CK7) and CK19 were 35.1% and 20.6% respectively. The positive rate of CK19 was significantly higher in cases with age < 47 years (P = 0.005), tumor diameter > 4 cm (P = 0.016) or AFP ≥ 400 ng/ml (P = 0.007). The TLR in the portal vein phase was significantly lower in CK19 positive group (P = 0.024). The recurrence risk was significantly higher in cases with CK19 positive (HR: 2.17, 95% CI 1.16 to 4.04, P = 0.013), tumor diameter > 4 cm (HR: 2.05, 95% CI 1.11 to 3.78, P = 0.019), AFP ≥ 400 ng/ml (HR: 2.50, 95% CI 1.37 to 4.54, P = 0.002) or CA199 ≥ 37 U/ml (HR: 2.23, 95% CI 1.12 to 4.42, P = 0.020). However, imaging features, pathological subtype, CK7 or CK19 expression were not significantly related to HCC OS in the univariate and multivariate analysis (all P > 0.05). The expression of CK19 may be associated with the enhancement feature of the portal vein phase CT image, and CK19 positive may suggest a worse RFS.

Hepatocellular carcinoma with lung metastasis showing hemochromatosis in an Egyptian fruit bat (Rousettus aegyptiacus)

After an Egyptian fruit bat (Rousettus aegyptiacus) in a zoo became emaciated and died, a necropsy revealed multiple nodules on the liver and lung surfaces. Microscopy revealed that the liver nodules consisted of neoplastic hepatocytes and showed metastasis in the lung lobes. Most of the neoplastic cells in the liver and lung showed positive labeling for HepPar-1, cytokeratin 19, glypican-3, and Ki-67. Hepatocellular degeneration and necrosis were diffuse in the liver parenchyma. Berlin blue staining revealed large amounts of iron in normal and neoplastic cells. Based on these pieces of evidence, this case was diagnosed as hepatocellular carcinoma with hemochromatosis. This is believed to be the first report of hepatocellular carcinoma in an Egyptian fruit bat that has been immunophenotypically examined in detail by pathological examination.

British Society of Gastroenterology guidelines for the diagnosis and management of cholangiocarcinoma

These guidelines for the diagnosis and management of cholangiocarcinoma (CCA) were commissioned by the British Society of Gastroenterology liver section. The guideline writing committee included a multidisciplinary team of experts from various specialties involved in the management of CCA, as well as patient/public representatives from AMMF (the Cholangiocarcinoma Charity) and PSC Support. Quality of evidence is presented using the Appraisal of Guidelines for Research and Evaluation (AGREE II) format. The recommendations arising are to be used as guidance rather than as a strict protocol-based reference, as the management of patients with CCA is often complex and always requires individual patient-centred considerations.

The value of MRI in predicting hepatocellular carcinoma with cytokeratin 19 expression: a systematic review and meta-analysis

AIM

To evaluate the overall diagnostic performance of magnetic resonance imaging (MRI), different image features, and different image analysis methods in predicting hepatocellular carcinoma (HCC) with cytokeratin 19 (CK19) expression.

MATERIALS AND METHODS

A systematic literature search was performed to identify studies using MRI to predict HCC with CK19 expression between 2012 and 2023. Data were extracted to calculate the pooled sensitivity and specificity. Overall diagnostic performance was assessed using areas under the summary receiver operating characteristic curve (AUC). Subgroup analyses were conducted for specific image features and according to image analysis methods (traditional image feature, radiomics, and combined methods). Z-test statistics was used to analyse the differences in diagnostic performance between combined and individual methods.

RESULTS

Eleven studies with 14 datasets (1,278 lesions from 1,264 patients) were included. The overall pooled sensitivity, specificity, and AUC with corresponding 95% confidence intervals were estimated to be 0.72 (0.55, 0.85), 0.88 (0.80, 0.93), and 0.89 (0.86, 0.91) for MRI in predicting HCC with CK19 expression. Combined methods had higher sensitivity than image feature methods (0.86 versus 0.54, p=0.001), with no difference in specificity (0.85 versus 0.87, p=0.641). There were no significant differences between radiomics and combined methods regarding sensitivity (p=0.796) and specificity (p=0.535), respectively.

CONCLUSION

MRI shows moderate sensitivity and high specificity in identifying HCC with CK19 expression. The application of radiomics can improve the sensitivity of MRI in identifying HCC with CK19 expression.

Subcentimeter hepatocellular carcinoma (HCC) on gadoxetic-acid-enhanced MRI: less frequent typical imaging features compared to 1-2 cm HCC but better prognosis after surgical resection

PURPOSE

To compare the imaging features, pathologic characteristics, and survival outcomes between subcentimeter and 1-2 cm hepatocellular carcinoma (HCC).

METHODS

This retrospective observational study evaluated the imaging features and medical records of patients with HCC smaller than 2 cm who underwent surgical resection with preoperative gadoxetic-acid-enhanced MRI (EOB-MRI) from January 2013 to December 2021. The incidence of EOB-MRI features and pathological characteristics between the subcentimeter and 1-2 cm HCC were compared. The recurrence-free survival (RFS), including early and overall tumor recurrence, and overall survival (OS) were assessed.

RESULTS

A total of 223 patients (82 with subcentimeter HCC and 141 with 1-2 cm HCC, 179 men) were enrolled. Compared with 1-2 cm HCC, subcentimeter HCC showed fewer restricted diffusion (87.8 vs. 95.7%, P = 0.027), portal-phase washout (58.5% vs. 73.8%, P = 0.013), typical enhancement pattern (50.0% vs. 66.7%, P =0.014), and microvascular invasion (4.9% vs. 14.9%, P = 0.022). Patients with subcentimeter HCC had higher RFS (P = 0.027) and better OS (P = 0.029). The estimated RFS rates at 5 years was 83.3% for subcentimeter HCC and 67.3% for 1-2 cm HCC, respectively. The estimated OS rates at 5 years was 97.3% for subcentimeter HCC and 89.5% for 1-2 cm HCC, respectively.

CONCLUSION

Subcentimeter HCC showed less frequent EOB-MRI features seen typically in 1-2 cm HCC but better survival outcomes. Therefore, tailored early diagnostic criteria and immediate treatment for subcentimeter HCC may be warranted.

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

Advances in Histological and Molecular Classification of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a primary liver cancer characterized by hepatocellular differentiation. HCC is molecularly heterogeneous with a wide spectrum of histopathology. The prognosis of patients with HCC is generally poor, especially in those with advanced stages. HCC remains a diagnostic challenge for pathologists because of its morphological and phenotypic diversity. However, recent advances have enhanced our understanding of the molecular genetics and histological subtypes of HCC. Accurate diagnosis of HCC is important for patient management and prognosis. This review provides an update on HCC pathology, focusing on molecular genetics, histological subtypes, and diagnostic approaches.

Challenges in Diagnosing and Reporting Cholangiocarcinoma

Intrahepatic cholangiocarcinoma is a challenge to the practicing surgical pathologist for several reasons. It is rare in many parts of the world, and thus practical exposure may be limited. Related to the fact of its rarity is the fact that more common tumors which frequently metastasize to the liver can be morphologically indistinguishable (eg, pancreatic ductal adenocarcinoma). Immunohistochemical testing is generally non-contributory in this context. Other difficulties arise from the protean morphologic manifestations of cholangiocarcinoma (ie, small duct vs. large duct) and the existence of combined cholangiocarcinoma and hepatocellular carcinoma. These, and other issues of concern to the practicing diagnostic pathologist are discussed herein.

Characterization of Circulating Tumor Cells Using Imaging Flow Cytometry in Liver Disease Patients

Background

Hepatocellular carcinoma (HCC) is asymptomatic at an early stage which delays its timely diagnosis and treatment. Circulating tumor cells (CTCs), derived from a primary or secondary tumor, may help in the management of HCC. Here, we evaluate and characterize CTCs in liver disease patients.

Methods

In total, 65 patients, categorized into liver cirrhosis (LC) (n = 30) and HCC (n = 35), were enrolled. Using ImagestreamX MkII imaging flow cytometer, CTCs were detected and characterized using biomarker expression of EpCAM, CK, AFP, CD45, and DRAQ5 in LC and HCC patients.

Results

CTCs were detected in 33/35 (94%) HCC patients and in 28/30 (93%) LC patients. In the HCC group, the number of biomarker-positive CTCs was higher in BCLC stage D when compared with others. EpCAM + CK was the most expressed biomarker on CTCs in LC versus HCC (83.3% vs. 77.14%), followed by AFP (80% vs. 65.71%), EpCAM (30% vs. 28.57%), and CK (16.6% vs. 14.28%). The EpCAM cell area was significantly associated (P value = 0.031) with the CTC-positive status. The combination biomarker expression of CTCs cell area (EpCAM, CK, and AFP) performed well with the area under the curve of 0.92, high sensitivity, and specificity in detecting early-stage and AFP-negative HCC as well as in AFP-negative LC cases.

Conclusion

Enumeration and cell area of CTCs may be used as a biomarker for early detection of HCC and guiding treatment.

Three-dimensional multifrequency magnetic resonance elastography improves preoperative assessment of proliferative hepatocellular carcinoma

BACKGROUND

To investigate the viscoelastic signatures of proliferative hepatocellular carcinoma (HCC) using three-dimensional (3D) magnetic resonance elastography (MRE).

METHODS

This prospective study included 121 patients with 124 HCCs as training cohort, and validation cohort included 33 HCCs. They all underwent preoperative conventional magnetic resonance imaging (MRI) and tomoelastography based on 3D multifrequency MRE. Viscoelastic parameters of the tumor and liver were quantified as shear wave speed (c, m/s) and loss angle (φ, rad), representing stiffness and fluidity, respectively. Five MRI features were evaluated. Multivariate logistic regression analyses were used to determine predictors of proliferative HCC to construct corresponding nomograms.

RESULTS

In training cohort, model 1 (Combining cirrhosis, hepatitis virus, rim APHE, peritumoral enhancement, and tumor margin) yielded an area under the curve (AUC), sensitivity, specificity, accuracy of 0.72, 58.73%,78.69%, 67.74%, respectively. When adding MRE properties (tumor c and tumor φ), established model 2, the AUC increased to 0.81 (95% CI 0.72-0.87), with sensitivity, specificity, accuracy of 71.43%, 81.97%, 75%, respectively. The C-index of nomogram of model 2 was 0.81, showing good performance for proliferative HCC. Therefore, integrating tumor c and tumor φ can significantly improve the performance of preoperative diagnosis of proliferative HCC (AUC increased from 0.72 to 0.81, p = 0.012). The same finding was observed in the validation cohort, with AUC increasing from 0.62 to 0.77 (p = 0.021).

CONCLUSIONS

Proliferative HCC exhibits low stiffness and high fluidity. Adding MRE properties (tumor c and tumor φ) can improve performance of conventional MRI for preoperative diagnosis of proliferative HCC.

CRITICAL RELEVANCE STATEMENT

We investigated the viscoelastic signatures of proliferative hepatocellular carcinoma (HCC) using three-dimensional (3D) magnetic resonance elastography (MRE), and find that adding MRE properties (tumor c and tumor φ) can improve performance of conventional MRI for preoperative diagnosis of proliferative HCC.

The Role of Immunohistochemistry in the Differential Diagnosis between Intrahepatic Cholangiocarcinoma, Hepatocellular Carcinoma and Liver Metastasis, as Well as Its Prognostic Value

Intrahepatic cholangiocarcinoma (iCCA) is the second most frequent primary hepatic malignant tumor, after hepatocellular carcinoma (HCC). Its incidence has risen worldwide, yet the only potentially curative treatment, surgical resection, is seldom applicable, and the median overall survival remains extremely low. So far, there are no personalized therapy regimens. This study investigated whether routine immunohistochemical stains have diagnostic and/or prognostic value in iCCA. Clinical, imaging, and pathology data were retrospectively gathered for patients diagnosed with iCCA, HCC, or liver metastases assessed using liver needle biopsies. Three study groups with an equal number of cases (n = 65) were formed. In the iCCA group, CK19, CA19-9, CK7, and CEA demonstrated the highest sensitivities (100%, 100%, 93.7%, and 82.6%, respectively). The most relevant stains used for diagnosing HCCs were Glypican 3, CD34 (sinusoidal pattern), and Hep Par 1, with corresponding sensitivities of 100%, 100%, and 98.2%. The immunohistochemical panels for diagnosing metastatic tumors were chosen after correlating the clinical data and morphologic H&E aspects. Moderate/intensely positive CK7 expression and absent/low amount of intratumoral immune cells were favorable prognostic factors and correlated with increased overall survival in both the univariate analysis and the multivariate regression adjusted for age, existence of cirrhosis, number of tumors, and tumor differentiation.

A Statistical Approach to the Diagnosis and Prediction of HCC Using CK19 and Glypican 3 Biomarkers

Various statistical models predict the probability of developing hepatocellular carcinoma (HCC) in patients with cirrhosis, with GALAD being one of the most extensively studied scores. Biomarkers like alpha-fetoprotein (AFP), AFP-L3, and des-g-carboxyprothrombin (DCP) are widely used alone or in conjunction with ultrasound to screen for HCC. Our study aimed to compare the effectiveness of Cytokeratin 19 (CK19) and Glypican-3 (GPC3) as standalone biomarkers and in a statistical model to predict the likelihood of HCC. We conducted a monocentric prospective study involving 154 participants with previously diagnosed liver cirrhosis, divided into two groups: 95 patients with confirmed HCC based on clinical, biological, and imaging features and 59 patients without HCC. We measured the levels of AFP, AFP-L3, DCP, GPC3, and CK19 in both groups. We used univariate and multivariate statistical analyses to evaluate the ability of GPC3 and CK19 to predict the presence of HCC and incorporated them into a statistical model—the GALKA score—which was then compared to the GALAD score. AFP performed better than AFP-F3, DCP, GPC3, and CK19 in predicting the presence of HCC in our cohort. Additionally, GPC3 outperformed CK19. We used multivariate analysis to compute the GALKA score to predict the presence of HCC. Using these predictors, the following score was formulated: 0.005*AFP-L3 + 0.00069*AFP + 0.000066*GPC3 + 0.01*CK19 + 0.235*Serum Albumin—0.277. The optimal cutoff was >0.32 (AUROC = 0.98, sensitivity: 96.8%, specificity: 93%, positive predictive value—95.8%, negative predictive value—94.8%). The GALKA score had a similar predictive value to the GALAD score for the presence of HCC. In conclusion, AFP, AFP-L3, and DCP were the best biomarkers for predicting the likelihood of HCC. Our score performed well overall and was comparable to the GALAD score.

The endocannabinoid system promotes hepatocyte progenitor cell proliferation and maturation by modulating cellular energetics

The proliferation and differentiation of hepatic progenitor cells (HPCs) drive the homeostatic renewal of the liver under diverse conditions. Liver regeneration is associated with an increase in Axin2⁺Cnr1⁺ HPCs, along with a marked increase in the levels of the endocannabinoid anandamide (AEA). But the molecular mechanism linking AEA signaling to HPC proliferation and/or differentiation has not been explored. Here, we show that in vitro exposure of HPCs to AEA triggers both cell cycling and differentiation along with increased expression of Cnr1, Krt19, and Axin2. Mechanistically, we found that AEA promotes the nuclear localization of the transcription factor β-catenin, with subsequent induction of its downstream targets. Systemic analyses of cells after CRISPR-mediated knockout of the β-catenin-regulated transcriptome revealed that AEA modulates β-catenin-dependent cell cycling and differentiation, as well as interleukin pathways. Further, we found that AEA promotes OXPHOS in HPCs when amino acids and glucose are readily available as substrates, but AEA inhibits it when the cells rely primarily on fatty acid oxidation. Thus, the endocannabinoid system promotes hepatocyte renewal and maturation by stimulating the proliferation of Axin2⁺Cnr1⁺ HPCs via the β-catenin pathways while modulating the metabolic activity of their precursor cells.

A Rare Case of Hepatocellular Carcinoma Recurrence in Ovarian Site after 12 Years Mimicking a Hepatoid Adenocarcinoma: Case Report

Hepatoid carcinoma of the ovary (HCO) is a tumor that resembles, both histologically and cytologically, hepatocarcinoma (HCC) in a patient with a non-cirrhotic liver not involved by the disease. Hepatoid carcinoma is an extremely rare histologic subtype of ovarian cancer and should be distinguished from metastatic HCC. Here, we report the rare case of a 67-year-old woman with ovarian recurrence of HCC 12 years after first diagnosis. The patient was being followed by oncologists because she had been diagnosed with HCV-related HCC (Edmonson and Stainer grade 2, pT2 N0 M0, G2, V1) in 2009. She had undergone surgery for enlarged left hepatectomy to the 4th hepatic segment with cholecystectomy and subsequent placement of a Kehr drain. The preoperative alpha-fetoprotein (AFP) level was 8600 ng/mL, while the postoperative value was only 2.7 ng/mL. At the first diagnosis, no other localizations of the disease, including the genital tract, were found. At the time of recurrence, however, the patient was completely asymptomatic: her liver function was within normal limits with negative blood indices, except for an increased blood dosage of AFP (467 ng/mL), and CA125, which became borderline (37.4 IU/mL). The oncologist placed an indication for a thoracic abdominal CT scan, which showed that the residual liver was free of disease, and the presence of a formation with a solid-cystic appearance and some calcifications at the left adnexal site. The radiological findings were confirmed on level II gynecological ultrasound. The patient then underwent a radical surgery of hysterectomy, bilateral oophorectomy, pelvic peritonectomy, and omentectomy by a laparotomic approach, with the sending of intraoperative extemporaneous histological examination on the annexus site of the tumor mass, obtaining RT = 0. Currently, the patient continues her gyneco-oncology follow-up simultaneously clinically, in laboratory, and instrumentally every 4 months. Our study currently represents the longest elapsed time interval between first diagnosis and disease recurrence, as evidenced by current data in the literature. This was a rather unique and difficult clinical case because of the rarity of the disease, the lack of scientific evidence, and the difficulty in differentiating the primary hepatoid phenotype of the ovary from an ovarian metastasis of HCC. Several multidisciplinary meetings for proper interpretation of clinical and anamnestic data, with the aid of immunohistochemistry (IHC) on histological slides were essential for case management.

Gadoxetic Acid-Enhanced MRI-Based Radiomics Signature: A Potential Imaging Biomarker for Identifying Cytokeratin 19-Positive Hepatocellular Carcinoma

Purpose

One subtype of hepatocellular carcinoma (HCC), with cytokeratin 19 expression (CK19+), has shown to be more aggressive and has a poor prognosis. However, CK19+ is determined by immunohistochemical examination using a surgically resected specimen. This study is aimed at establishing a radiomics signature based on preoperative gadoxetic acid-enhanced MRI for predicting CK19 status in HCC. Patients and Methods. Clinicopathological and imaging data were retrospectively collected from patients who underwent hepatectomy between February 2015 and December 2020. Patients who underwent gadoxetic acid-enhanced MRI and had CK19 results of histopathological examination were included. Radiomics features of the manually segmented lesion during the arterial, portal venous, and hepatobiliary phases were extracted. The 10 most reproducible and robust features at each phase were selected for construction of radiomics signatures, and their performance was evaluated by analyzing the area under the curve (AUC). The goodness of fit of the model was assessed by the Hosmer-Lemeshow test.

Results

A total of 110 patients were included. The incidence of CK19(+) HCC was 17% (19/110). Alpha fetoprotein was the only significant clinicopathological variable different between CK19(-) and CK19(+) groups. A majority of the selected radiomics features were wavelet filter-derived features. The AUCs of the three radiomics signatures based on arterial, portal venous, and hepatobiliary phases were 0.70 (95% CI: 0.56-0.83), 0.83 (95% CI: 0.73-0.92), and 0.89 (95% CI: 0.82-0.96), respectively. The three radiomics signatures were integrated, and the fusion signature yielded an AUC of 0.92 (95% CI: 0.86-0.98) and was used as the final model for CK19(+) prediction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the fusion signature was 0.84, 0.89, 0.88, 0.62, and 0.96, respectively. The Hosmer-Lemeshow test showed a good fit of the fusion signature (p > 0.05).

Conclusion

The established radiomics signature based on preoperative gadoxetic acid-enhanced MRI could be an accurate and potential imaging biomarker for HCC CK19(+) prediction.

Subcentimeter Nodules with Diagnostic Hallmarks of Hepatocellular Carcinoma: Comparison of Pathological Features and Survival Outcomes with Nodules Measuring 1-2 cm

Objective

To compare the pathologic diagnosis and survival of patients with subcentimeter and 1-2 cm nodules that present with diagnostic hallmarks of hepatocellular carcinoma (HCC).

Methods

Diagnostic hallmarks of HCC were defined as hyperintensity on T2 weighted imaging, restricted diffusion, arterial phase hyperenhancement, washout on portal venous phase, and hypointensity on hepatobiliary phase. We retrospectively included 139 patients undergoing curative resection with single nodules ≤2 cm that present imaging features described above on gadoxetic acid-enhanced MRI. The final diagnosis was confirmed by histopathological assessment. Recurrence-free survival (RFS) was compared using Kaplan-Meier analysis with the Log-rank test. Factors associated with overall and early recurrence were identified using Cox regression analysis.

Results

Among 139 nodules (49 nodules <1 cm), there was no significant difference in the percentage of HCC between subcentimeter and 1-2 cm nodules (94.0% vs 94.4%, P > 0.999). Microvascular invasion (MVI) was less common in subcentimeter HCC (4.3% vs 17.6%, P = 0.032). There were 27 recurrences during a median follow-up time of 46.7 months. Patients with subcentimeter HCC achieved less recurrence, with a 5-year RFS rate of 87.3%. The MVI-positive patients had more early and overall recurrence. A tumor size <1 cm was associated with lower overall recurrence (HR, 0.336; P = 0.047). No factors were independently associated with early recurrence.

Conclusion

Subcentimeter nodules with diagnostic hallmarks of HCC are highly associated with HCC diagnosis and achieve less tumor recurrence after resection. Early diagnosis and treatment of subcentimeter HCC may be more appropriate.

Dynamic CT and Gadoxetic Acid-enhanced MRI Characteristics of P53-mutated Hepatocellular Carcinoma

Background Imaging markers of hepatocellular carcinoma (HCC) on the basis of molecular classification are important for predicting malignancy grade and prognosis. P53-mutated HCC is a major aggressive subtype; however, its imaging characteristics have not been clarified. Purpose To clarify the imaging characteristics of P53-mutated HCC at dynamic CT and gadoxetic acid-enhanced MRI that are correlated with its clinical features, pathologic findings, and prognosis. Materials and Methods In this retrospective single-center study, patients with surgically resected HCC between January 2015 and May 2018 in a university hospital were evaluated. HCC was classified into P53-mutated HCC and non-P53-mutated HCC using immunostaining. Dynamic CT and gadoxetic acid-enhanced MRI findings, clinical features, pathologic findings, and prognosis were compared using Mann-Whitney test, χ² test, multivariable regression analysis, receiver operating characteristic analysis, Kaplan-Meier method, and log-rank test. Immunohistochemical expression of P53, organic anion transporting polypeptide 1B3 (OATP1B3), and CD34 were evaluated, and the correlations were analyzed using the Pearson correlation test. Results In total, 149 patients (mean age, 67 years ± 9 [SD]; 103 men) with 173 HCCs were evaluated. P53-mutated HCC (n = 28) demonstrated higher serum α-fetoprotein (median, 127.5 ng/mL vs 5.5 ng/mL; P < .001), larger size (40.4 mm ± 29.7 vs 26.4 mm ± 20.5; P = .001), and higher rates of poorly differentiated HCC (22 of 28 [79%] vs 24 of 145 [17%]; P < .001). Dilated vasculature in the arterial phase of dynamic CT (odds ratio, 14; 95% CI: 3, 80; P = .002) and a lower relative enhancement ratio in the hepatobiliary phase (odds ratio, 0.05; 95% CI: 0.01, 0.34; cutoff value, 0.69; P = .002) independently predicted P53-mutated HCC. OATP1B3 expression and P53 expression were inversely correlated (P = .002; R = -0.24). Five-year overall survival was worse for P53-mutated HCC (50.0% vs 72.6%; P = .02). Conclusion Dilated vasculature at the arterial phase of dynamic CT and a lower relative enhancement ratio at the hepatobiliary phase of gadoxetic acid-enhanced MRI were useful markers for P53-mutated hepatocellular carcinoma with poor prognosis. © RSNA, 2022 Online supplemental material is available for this article.

Is liver regeneration key in hepatocellular carcinoma development?

The liver is the largest organ of the mammalian body and has the remarkable ability to fully regenerate in order to maintain tissue homeostasis. The adult liver consists of hexagonal lobules, each with a central vein surrounded by six portal triads localized in the lobule border containing distinct parenchymal and nonparenchymal cells. Because the liver is continuously exposed to diverse stress signals, several sophisticated regenerative processes exist to restore its functional status following impairment. However, these stress signals can affect the liver's capacity to regenerate and may lead to the development of hepatocellular carcinoma (HCC), one of the most aggressive liver cancers. Here, we review the mechanisms of hepatic regeneration and their potential to influence HCC development.

Pathology of Combined Hepatocellular Carcinoma-Cholangiocarcinoma: An Update

Combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer that is composed of both hepatocellular and cholangiocellular differentiated cells. It is slightly more common in men and among Asian and Pacific islanders. Overall, risk factors are similar to classic risk factors of hepatocellular carcinoma (HCC). The classification has significantly evolved over time. The last WHO classification (2019) mainly emphasized diagnosis on morphological basis with routine stainings, discarded previously recognized classifications with carcinomas with stem cell features, introduced intermediate cell carcinoma as a specific subtype and considered cholangiolocarcinoma as a subtype of cholangiocellular carcinoma. Immunohistochemical markers may be applied for further specification but have limited value for diagnosis. Recent discoveries in molecular pathway regulation may pioneer new therapeutic approaches for this poor prognostic and challenging diagnosis.

SOX9 Expression Is Superior to Other Stem Cell Markers K19 and EpCAM in Predicting Prognosis in Hepatocellular Carcinoma

Various stem cell markers (eg, epithelial cell adhesion molecule [EpCAM], cytokeratin 19 [K19]) have been reported as predictors of poor prognosis in hepatocellular carcinoma (HCC). However, the data remain limited, particularly in Western populations, and are often contradictory. In this study, the prognostic value of positive SOX9 immunohistochemistry was compared with that of more established markers EpCAM and K19 in a large cohort (n=216) of North American patients. The independent HCC cohort in The Cancer Gene Atlas (n=360) was utilized to validate our findings. Finally, molecular signatures associated with SOX9 -high HCC were determined. We found that the expression of SOX9, but not EpCAM or K19, was associated with worse overall survival and disease-free survival (DFS) and was an independent prognostic factor for DFS in our North American cohort, in which hepatitis C infection was the most common underlying etiology. High SOX9 mRNA level, but not increased expression of EpCAM mRNA or K19 mRNA, was also associated with worse DFS and was an independent prognostic factor for DFS in The Cancer Gene Atlas cohort. This group had underlying causes, including an increased incidence of hepatitis B, significantly different from our initial cohort. High SOX9 mRNA level is associated with molecular pathways important in HCC pathogenesis. Increased SOX9 expression is clinically and biologically relevant for HCC arising in patients with a variety of underlying etiologies. Immunohistochemistry for SOX9 is a reliable proxy for increased SOX9 mRNA and can be used to predict prognosis in HCC cases.

Prognostic implications of CT/MRI LI-RADS in hepatocellular carcinoma: State of the art and future directions

Hepatocellular carcinoma (HCC) is the fourth most lethal malignancy with an increasing incidence worldwide. Management of HCC has followed several clinical staging systems that rely on tumour morphologic characteristics and clinical variables. However, these algorithms are unlikely to profile the full landscape of tumour aggressiveness and allow accurate prognosis stratification. Noninvasive imaging biomarkers on computed tomography (CT) or magnetic resonance imaging (MRI) exhibit a promising prospect to refine the prognostication of HCC. The Liver Imaging Reporting and Data System (LI-RADS) is a comprehensive system for standardizing the terminology, techniques, interpretation, reporting and data collection of liver imaging. At present, it has been widely accepted as an effective diagnostic system for HCC in at-risk patients. Emerging data have provided new insights into the potential of CT/MRI LI-RADS in HCC prognostication, which may help refine the prognostic paradigm of HCC that promises to direct individualized management and improve patient outcomes. Therefore, this review aims to summarize several prognostic imaging features at CT/MRI for patients with HCC; the available evidence regarding the use of LI-RDAS for evaluation of tumour biology and clinical outcomes, pitfalls of current literature, and future directions for LI-RADS in the management of HCC.

Ultrasomics prediction for cytokeratin 19 expression in hepatocellular carcinoma: A multicenter study

Objective

The purpose of this study was to investigate the preoperative prediction of Cytokeratin (CK) 19 expression in patients with hepatocellular carcinoma (HCC) by machine learning-based ultrasomics.

Methods

We retrospectively analyzed 214 patients with pathologically confirmed HCC who received CK19 immunohistochemical staining. Through random stratified sampling (ratio, 8:2), patients from institutions I and II were divided into training dataset (n = 143) and test dataset (n = 36), and patients from institution III served as external validation dataset (n = 35). All gray-scale ultrasound images were preprocessed, and then the regions of interest were then manually segmented by two sonographers. A total of 1409 ultrasomics features were extracted from the original and derived images. Next, the intraclass correlation coefficient, variance threshold, mutual information, and embedded method were applied to feature dimension reduction. Finally, the clinical model, ultrasonics model, and combined model were constructed by eXtreme Gradient Boosting algorithm. Model performance was assessed by area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy.

Results

A total of 12 ultrasomics signatures were used to construct the ultrasomics models. In addition, 21 clinical features were used to construct the clinical model, including gender, age, Child-Pugh classification, hepatitis B surface antigen/hepatitis C virus antibody (positive/negative), cirrhosis (yes/no), splenomegaly (yes/no), tumor location, tumor maximum diameter, tumor number, alpha-fetoprotein, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, glutamyl-transpeptidase, albumin, total bilirubin, conjugated bilirubin, creatinine, prothrombin time, fibrinogen, and international normalized ratio. The AUC of the ultrasomics model was 0.789 (0.621 – 0.907) and 0.787 (0.616 – 0.907) in the test and validation datasets, respectively. However, the performance of the combined model covering clinical features and ultrasomics signatures improved significantly. Additionally, the AUC (95% CI), sensitivity, specificity, and accuracy were 0.867 (0.712 – 0.957), 0.750, 0.875, 0.861, and 0.862 (0.703 – 0.955), 0.833, 0.862, and 0.857 in the test dataset and external validation dataset, respectively.

Conclusion

Ultrasomics signatures could be used to predict the expression of CK19 in HCC patients. The combination of clinical features and ultrasomics signatures showed excellent effects, which significantly improved prediction accuracy and robustness.

MRI features of histologic subtypes of hepatocellular carcinoma: correlation with histologic, genetic, and molecular biologic classification

HCC is a heterogeneous group of tumors in terms of histology, genetic aberration, and protein expression. Advancements in imaging techniques have allowed imaging diagnosis to become a critical part of managing HCC in the clinical setting, even without pathologic diagnosis. With the identification of many HCC subtypes, there is increasing correlative evidence between imaging phenotypes and histologic, molecular, and genetic characteristics of various HCC subtypes. In this review, current knowledge of histologic heterogeneity of HCC correlated to features on gadolinium-enhanced dynamic liver MRI will be discussed. In addition, HCC subtype classification according to transcriptomic profiles will be outlined with descriptions of histologic, genetic, and molecular characteristics of some relatively well-established morphologic subtypes, namely the low proliferation class (steatohepatitic HCC and CTNNB1-mutated HCC) and the high proliferation class (macrotrabecular-massive HCC (MTM-HCC), scirrhous HCC, and CK19-positive HCC). Characteristics of sarcomatoid HCC and fibrolamellar HCC will also be discussed. Further research on radiological characteristics of HCC subtypes may ultimately enable non-invasive diagnosis and serve as a biomarker in predicting prognosis, molecular characteristics, and therapeutic response. In the era of precision medicine, a multidisciplinary effort to develop an integrated radiologic and clinical diagnostic system of various HCC subtypes is necessary. KEY POINTS: • HCC is a heterogeneous group of tumors in terms of histology, genetic aberration, and protein expression, which can be divided into many subtypes according to transcriptome profiles. • There is increasing evidence of a correlation between imaging phenotypes and histologic, genetic, and molecular biologic characteristics of various HCC subtypes. • Imaging characteristics may ultimately enable non-invasive diagnosis and subtype characterization, serving as a biomarker for predicting prognosis, molecular characteristics, and therapeutic response.

Hepatocellular carcinomas in captive prosimians

We performed a retrospective examination of spontaneous hepatocellular carcinomas (HCCs) (primary and metastatic tumors) in 14 captive prosimians brought to the Veterinary Medical Diagnostic Laboratory in North Carolina State University over a period of 11 years (2003 to 2014) to characterize the tumors. These animals are endangered primates; a better understanding of the main fatal neoplasms is crucial. In addition to the histologic evaluation, an immunohistochemical study was also performed, using a hepatocyte marker (hepatocyte paraffin 1 [HepPar-1]) and 2 cholangiocyte markers (keratin 7 [K7] and keratin 19 [K19]), in an attempt to identify a specific profile for HCCs with metastatic behavior. Six of the 14 HCCs had pulmonary metastases. The most frequent histopathological findings were a trabecular pattern (14/14, 100%), presence of multinucleated cells (12/14, 85.7%), and foci of extramedullary hematopoiesis (9/14, 64.3%). The mitotic count was significantly higher in the metastatic HCCs (P < .05). HepPar-1 was detected in all primary and metastatic HCCs, with a strong intensity of staining. Labeling for K7 and K19 was positive in 12 HCCs (85.7%) and 1 HCC (7.1%), respectively. Contrary to the less aggressive HCCs, most of the metastatic HCCs (5/6) expressed K7 in more than 15% of cells. The percentage of K7-positive neoplastic hepatocytes was significantly higher in metastatic HCCs. This study suggests that K7 might be a prognostically relevant marker in HCCs of captive prosimians.

The Role of Chronic Liver Diseases in the Emergence and Recurrence of Hepatocellular Carcinoma: An Omics Perspective

Hepatocellular carcinoma (HCC) typically develops from a background of cirrhosis resulting from chronic inflammation. This inflammation is frequently associated with chronic liver diseases (CLD). The advent of next generation sequencing has enabled extensive analyses of molecular aberrations in HCC. However, less attention has been directed to the chronically inflamed background of the liver, prior to HCC emergence and during recurrence following surgery. Hepatocytes within chronically inflamed liver tissues present highly activated inflammatory signaling pathways and accumulation of a complex mutational landscape. In this altered environment, cells may transform in a stepwise manner toward tumorigenesis. Similarly, the chronically inflamed environment which persists after resection may impact the timing of HCC recurrence. Advances in research are allowing an extensive epigenomic, transcriptomic and proteomic characterization of CLD which define the emergence of HCC or its recurrence. The amount of data generated will enable the understanding of oncogenic mechanisms in HCC from the CLD perspective and provide the possibility to identify robust biomarkers or novel therapeutic targets for the treatment of primary and recurrent HCC. Importantly, biomarkers defined by the analysis of CLD tissue may permit the early detection or prevention of HCC emergence and recurrence. In this review, we compile the current omics based evidence of the contribution of CLD tissues to the emergence and recurrence of HCC.

Individual and joint influence of cytokeratin 19 and microvascular invasion on the prognosis of patients with hepatocellular carcinoma after hepatectomy

BACKGROUND AND OBJECTIVES

To evaluate the individual and combined associations of cytokeratin 19 (CK19) and microvascular invasion (MVI) with prognosis of patients with hepatocellular carcinoma (HCC).

METHODS

Clinicopathological data on 352 patients with HCC who underwent radical resection at our hospital between January 2013 and December 2015 were retrospectively analyzed. Patients were divided into four groups: CK19(-)/MVI(-), CK19(-)/MVI(+), CK19(+)/MVI(-), and CK19(+)/MVI(+).

RESULTS

Of the 352 HCC patients, 154 (43.8%) were CK19(-)/MVI(-); 116 (33.0%), CK19(-)/MVI(+); 31 (8.8%), CK19(+)/MVI(-); and 51 (14.5%), CK19(+)/MVI(+). The disease-free survival of CK19(-)/MVI(-) patients was significantly higher than that of CK19(-)/MVI(+) patients and CK19(+)/MVI(+) patients. Similar results were observed for overall survival. CK19(+)/MVI(+) patients showed significantly lower overall survival than the other three groups.

CONCLUSIONS

CK19 expression and MVI predict poor prognosis after radical resection of HCC, and the two markers jointly contribute to poor OS. Combining CK19 and MVI may predict post-resection prognosis better than using either factor on its own.

Decreased ARG1 expression as an adverse prognostic phenotype in non-alcoholic non-virus-related hepatocellular carcinoma

The incidence of non-alcoholic non-virus-related hepatocellular carcinoma (NANV-HCC) is increasing along with the growing prevalence of metabolic disorders. In this subset, few useful biomarkers are available to narrow down the high-risk group for recurrence. This study aimed to evaluate the prognostic impact of decreased ARG1 (arginase-1), which is pathologically known as a marker reflecting hepatocyte differentiation, in NANV-HCC. Besides, its relationship with biliary/progenitor cell markers, whose expressions are associated with poor prognosis, was also assessed. To reveal the clinicopathological association of decreased ARG1 expression in NANV-HCC, we investigated 99 patients who underwent curative-intent hepatectomy for NANV-HCC. Tissue microarrays were employed for immunohistochemical analysis. A total of 21 NANV-HCC cases (21%; 21/99) showed decreased ARG1 expression. Decreased ARG1 expression was an independent prognostic factor for both poor DFS (hazard ratio 2.17; 95% confidence interval 1.15-4.09; p = 0.02) and OS (hazard ratio 4.09; 95% confidence interval 1.71-9.80; p = 0.002). In addition, decreased ARG1 expression was significantly associated with expressions of biliary/progenitor cell markers, CK19 and CD56 (p < 0.01). As cytologic features of tumor cells, decreased ARG1 expression was significantly associated with lipid-less cytologic morphology (p = 0.045). These findings indicate that decreased ARG1 expression is a predictive phenotype of postoperative recurrence with poor prognosis in patients with NANV-HCC. Decreased ARG1 expression may be a precursor or overlapping feature with biliary/progenitor cell marker expressions in NANV-HCC.

Cytokeratin 7 and cytokeratin 20 expression in cancer: A tissue microarray study on 15,424 cancers

Combined analysis of cytokeratin 7 (CK7) and cytokeratin 20 (CK20) is often used for assessing the origin of metastatic cancer. To evaluate the diagnostic utility of CK7 and CK20, tissue microarrays containing 15,424 samples from 120 different tumor types and subtypes and 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry. CK7 positivity was seen in 52% (8.7% weak, 5.9% moderate, 37% strong) and CK20 positivity in 23% (5.1% weak, 3.4% moderate, 15% strong) of interpretable tumors. Of 8390 positive tumors, 1181 (14%) showed positivity for CK7 and CK20, 5380 (64%) showed positivity for CK7 alone, and 1829 (22%) showed positivity for CK20 alone. CK20 predominated in gastrointestinal tract, urothelial and Merkel cell carcinomas. CK7 was usually negative in prostate cancer and colorectal cancer. Combined evaluation of CK7/CK20 revealed the best diagnostic utility in CK20 positive tumors, where CK7 negativity is often linked to colorectal origin while CK7 positivity argues for urothelial origin or mucinous ovarian cancer. Associations with unfavorable tumor features were found for cytokeratin 7 loss in breast cancer of no special type, urothelial and renal cell carcinomas, for CK7 overexpression in high-grade serous ovarian and gastric cancer, and for CK20 overexpression in urothelial carcinoma. CK20 loss was linked to MSI in gastric (p = 0.0291) and colorectal adenocarcinoma (p < 0.0001). These analyses provide comprehensive data on the frequency of CK7 and CK20 immunostaining - alone or in combination - in human cancers. These data facilitate interpretation of CK7/CK20 immunostaining in cancers.

Risk stratification of LI-RADS M and LI-RADS 4/5 combined hepatocellular cholangiocarcinoma: prognostic values of MR imaging features and clinicopathological factors

OBJECTIVES

To investigate the role of clinicopathological factors and MR imaging factors in risk stratification of combined hepatocellular cholangiocarcinoma (cHCC-CCA) patients who were classified as LR-M and LR-4/5.

METHODS

We retrospectively identified consecutive patients who were confirmed as cHCC-CCA after surgical surgery in our institution from June 2015 to November 2020. Two radiologists evaluated the preoperative MR imaging features independently, and each lesion was assigned with a LI-RADS category. Preoperative clinical data were also collected. Multivariate Cox proportional hazards model was applied to separately identify the independent factors correlated with the recurrence of cHCC-CCAs in LR-M and LR-4/5. Risk stratifications were conducted separately in LR-M and LR-4/5. Recurrence-free survival (RFS) rates and overall survival (OS) rates were analyzed by using the Kaplan-Meier survival curves and log-rank test.

RESULTS

A total of 131 patients with single primary lesion which met the 2019 WHO classification criteria were finally included. Corona enhancement, delayed central enhancement, and microvascular invasion (MVI) were identified as predictors of RFS in LR-M. Mosaic architecture, CA19-9, and MVI were independently associated with RFS in LR-4/5. Based on the number of these independent predictors, patients were stratified into favorable-outcome groups (LR-ML subgroup and LR-4/5L subgroup) and dismal-outcome groups (LR-MH subgroup and LR-4/5H subgroup). The corresponding median RFS for LR-ML, LR-MH, LR-5L, and LR-5H were 25.6 months, 8.2 months, 51.7 months, and 18.1 months.

CONCLUSION

Our study explored the prognostic values of imaging and clinicopathological factors for LR-M and LR-4/5 cHCC-CCA patients, and different survival outcomes were observed among four subgroups after conducting risk stratifications.

KEY POINTS

• Corona enhancement, delayed central enhancement, and MVI were identified as predictors of RFS in cHCC-CCAs which were classified into LR-M. Mosaic architecture, CA19-9, and MVI were independently associated with RFS in cHCC-CCAs which were classified into LR-4/5. • Based on the identified risk factors, LR-M and LR-4/5 cHCC-CCA patients could be stratified into two subgroups respectively, with significantly different RFS and OS. • cHCC-CCA patients from LR-M did not always have worse RFS and OS than those from LR-4/5 in some cases.

Correlation between Immunohistochemical Markers in Hepatocellular Carcinoma Cells and In Vitro High-Throughput Drug Sensitivity Screening

AIM

This study analyzed the correlation between immunohistochemical markers in hepatocellular carcinoma cells and the results of in vitro high-throughput drug sensitivity screening, to provide a reference for individualized drug treatment in patients with liver cancer.

METHODS

Seventy-four patients with hepatocellular carcinoma were included in this study from December 2019 to June 2021, and their liver cancer cells were used for in vitro high-throughput drug sensitivity screening. According to the screening results, the patients were divided into relatively sensitive and insensitive groups, and the correlations between sensitivity and immunohistochemistry results were analyzed statistically.

RESULTS

Alpha-fetoprotein (AFP)-positive liver cancer cells were significantly more sensitive to gemcitabine than AFP-negative cells (χ ² = 6.102, P=0.014). AFP was also positively correlated with sensitivity of liver cancer cells to three combined regimens containing oxaliplatin (L-OHP) and epirubicin (EPI) : L-OHP + EPI + irinotecan + 5-fluorouracil (5-FU), L-OHP + irinotecan + EPI, and L-OHP + EPI (χ ² = 8.168, P=0.004, χ ² = 5.705, P=0.017, and χ ² = 8.275, P=0.004, respectively).

CONCLUSION

Gemcitabine and L-OHP + EPI + irinotecan + 5-FU, L-OHP + EPI, and L-OHP + irinotecan + EPI were more effective against AFP-positive compared with AFP-negative liver cancer cells according to in vitro high-throughput drug sensitivity screening. These results may guide the selection of personalized drug treatments for patients with advanced liver cancer in the future but still need further clinical studies to confirm.

Intrahepatic cholangiocarcinoma: tumour heterogeneity and its clinical relevance

Treatment of intrahepatic cholangiocarcinoma (iCCA) is currently at a significant turning point due to the identification of isocitrate dehydrogenase (IDH) mutations and fibroblast growth factor receptor (FGFR) fusions that can be targeted with currently available therapies. Clinical trials of these targeted therapies have been promising, and the iCCA patients who may benefit from these targeted treatments can be identified by pathological examination prior to molecular investigations. This is because IDH mutations and FGFR fusions are mainly seen in the small duct type iCCA, a subtype of iCCA defined by the 5th World Health Organization classification, which can be recognized by the pathological diagnostic process. Therefore, pathology plays an important role in precision medicine for iCCA, not only in confirming the diagnosis, but also in identifying the iCCA patients who may benefit from targeted treatments. However, caution is advised with the pathological diagnosis, as iCCA shows tumour heterogeneity, making it difficult to distinguish small duct type iCCA from hepatocellular carcinoma (HCC), and combined HCC-CCA. This review focuses on the pathological/molecular features of both subtypes of iCCA (large and small duct types), as well as their diagnostic pitfalls, clinical relevance, and future perspectives.

The transcriptome of early GGT/KRT19-positive hepatocellular carcinoma reveals a downregulated gene expression profile associated with fatty acid metabolism

Hepatocellular carcinoma expressing hepatobiliary progenitor markers, is considered of poor prognosis. By using a hepatocarcinogenesis model, laser capture microdissection, and RNA-Sequencing analysis, we identified an expression profile in GGT/KRT19-positive experimental tumors; 438 differentially expressed genes were found in early and late nodules along with increased collagen deposition. Dysregulated genes were involved in Fatty Acid Metabolism, RXR function, and Hepatic Stellate Cells Activation. Downregulation of Slc27a5, Acsl1, and Cyp2e1, demonstrated that Retinoid X Receptor α (RXRα) function is compromised in GGT/KRT19-positive nodules. Since RXRα controls NRF2 pathway activation, we determined the expression of NRF2 targeted genes; Akr1b8, Akr7a3, Gstp1, Abcc3, Ptgr1, and Txnrd1 were upregulated, indicating NRF2 pathway activation. A comparative analysis in human HCC showed that SLC27A5, ACSL1, CYP2E1, and RXRα gene expression is mutually exclusive with KRT19 gene expression. Our results indicate that the downregulation of Slc27a5, Acsl1, Rxrα, and Cyp2e1 genes is an early event within GGT/KRT19-positive HCC.

The distinct responsiveness of cytokeratin 19-positive hepatocellular carcinoma to regorafenib

Cytokeratin 19-positive (CK19+) hepatocellular carcinoma (HCC) is an aggressive subtype characterized by early recurrence and chemotherapy tolerance. However, there is no specific therapeutic option for CK19+ HCC. The correlation between tumor recurrence and expression status of CK19 were studied in 206 patients undergoing liver transplantation for HCC. CK19-/+ HCC cells were isolated to screen effective antitumor drugs. The therapeutic effects of regorafenib were evaluated in patient-derived xenograft (PDX) models from 10 HCC patients. The mechanism of regorafenib on CK19+ HCC was investigated. CK19 positiveness indicated aggressiveness of tumor and higher recurrence risk of HCC after liver transplantation. The isolated CK19+ HCC cells had more aggressive behaviors than CK19- cells. Regorafenib preferentially increased the growth inhibition and apoptosis of CK19+ cells in vitro, whereas sorafenib, apatinib, and 5-fluorouracil did not. In PDX models from CK19-/+ HCC patients, the tumor control rate of regorafenib achieved 80% for CK19+ HCCs, whereas 0% for CK19- HCCs. RNA-sequencing revealed that CK19+ cells had elevated expression of mitochondrial ribosomal proteins, which are essential for mitochondrial function. Further experiments confirmed that regorafenib attenuated the mitochondrial respiratory capacity in CK19+ cells. However, the mitochondrial respiration in CK19- cells were faint and hardly repressed by regorafenib. The mitochondrial respiration was regulated by the phosphorylation of signal transducer and activator of transcription 3 (STAT3), which was inhibited by regorafenib in CK19+ cells. Hence, CK19 could be a potential marker of the therapeutic benefit of regorafenib, which facilitates the individualized therapy for HCC. STAT3/mitochondria axis determines the distinct response of CK19+ cells to regorafenib treatment.

Global DNA 5hmC and CK195hmC+ Contents: A Promising Biomarker for Predicting Prognosis in Small Hepatocellular Carcinoma

Background: 5-Hydroxymethylcytosine (5hmC) with dynamic existence possesses multiple regulatory functions. Whereas, 5hmC’s impact on small hepatocellular carcinoma (SHCC) remains unclear. The present work focused on characterizing 5hmC content within SHCC and assessing the possibility of using global genomic 5hmC level as the predicative factor of clinical outcome. Methods: This study applied ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in measuring 5mC, 5fC and 5hmC contents. In addition, immunohistochemistry (IHC) was adopted to measure CK19 and 5hmC contents. Results: Research showed 5mC, 5hmC, and 5fC contents from global genomics of SHCC reduced extensively compared with healthy samples (p < 0.001). Moreover, SHCC was associated with lymph node metastasis (LNM). Greater 5mC and 5hmC levels were observed in non-metastasis group compared with the metastasis group (p < 0.001). Correlation analysis between the HBV DNA level and 5mC, 5fC and 5hmC levels exhibited that HBV DNA was associated with 5mC, 5hmC, and 5fC content reduction, which was verified in the cytological experiments. Moreover, 5hmC content had a negative correlation with the expression level of CK19 in SHCC. The decrease in 5hmC and CK19 containing 5hmC positive cell (called CK19^5hmC+) should be ascribed to the bad prognosis among SHCC patients. Conclusions: The contents of 5hmC and CK19^5hmC+ of genomic DNA might be adopted for predicting SHCC survival as an important biomarker.

MRI-Radiomics Prediction for Cytokeratin 19-Positive Hepatocellular Carcinoma: A Multicenter Study

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and has poor prognosis. Cytokeratin (CK)19-positive (CK19+) HCC is especially aggressive; early identification of this subtype and timely intervention can potentially improve clinical outcomes. In the present study, we developed a preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI)-based radiomics model for noninvasive and accurate classification of CK19+ HCC. A multicenter and time-independent cohort of 257 patients were retrospectively enrolled (training cohort, n = 143; validation cohort A, n = 75; validation cohort B, n = 39). A total of 968 radiomics features were extracted from preoperative multisequence MR images. The maximum relevance minimum redundancy algorithm was applied for feature selection. Multiple logistic regression, support vector machine, random forest, and artificial neural network (ANN) algorithms were used to construct the radiomics model, and the area under the receiver operating characteristic (AUROC) curve was used to evaluate the diagnostic performance of corresponding classifiers. The incidence of CK19+ HCC was significantly higher in male patients. The ANN-derived combined classifier comprising 12 optimal radiomics features showed the best diagnostic performance, with AUROCs of 0.857, 0.726, and 0.790 in the training cohort and validation cohorts A and B, respectively. The combined model based on multisequence MRI radiomics features can be used for preoperative noninvasive and accurate classification of CK19+ HCC, so that personalized management strategies can be developed.

Molecular phenotypes reveal heterogeneous engraftments of patient-derived hepatocellular carcinoma xenografts

Objective

Patient-derived xenograft (PDX) models provide a promising preclinical platform for hepatocellular carcinoma (HCC). However, the molecular features associated with successful engraftment of PDX models have not been revealed.

Methods

HCC tumor samples from 76 patients were implanted in immunodeficient mice. The molecular expression was evaluated by immunohistochemistry. Patient and tumor characteristics as well as tumor molecular expressions were compared for PDX engraftment using the Chi-square test. The independent prediction parameters were identified by logistic regression analyses.

Results

The engraftment rate for PDX models from patients with HCC was 39.47% (30/76). Tumors from younger patients and patients with elevated preoperative alpha-fetoprotein level had higher engraftment rates. Tumors with poor differentiation and vascular invasion were related to engraftment success. The positive expression of CK19, CD133, glypican-3 (GPC3), and Ki67 in tumor samples was associated with engraftment success. Logistic regression analyses indicated that GPC3 and Ki67 were two of the strongest predictors of PDX engraftment. Tumors with GPC3/Ki67 phenotypes showed heterogeneous engraftment rates, with 71.9% in GPC3⁺/Ki67⁺ tumors, 30.8% in GPC3⁻/Ki67⁺ tumors, 15.0% in GPC3⁺/Ki67⁻ tumors, and 0 in GPC3⁻/Ki67⁻ tumors.

Conclusions

Successful engraftment of HCC PDXs was significantly related to molecular features. Tumors with the GPC3⁺/Ki67⁺ phenotype were the most likely to successfully establish HCC PDXs.

Usefulness of Circulating CYFRA21-1 in Patients as a Biomarker in Patients Taking Sorafenib or Lenvatinib for Unresectable Hepatocellular Carcinoma

Background: This study investigated the impact of serum cytokeratin 19 fragment (CYFRA21-1) level on the clinical outcomes of patients with unresectable hepatocellular carcinoma (HCC) treated with sorafenib (SOR) or lenvatinib (LEN). Methods: A total of 71 cases with unresectable HCC taking SOR or LEN were included. Univariate and multivariate analyses were performed to identify the prognostic factors in patients taking SOR or LEN. Results: Among the 71 patients taking SOR or LEN, the frequency of cases showing high CYFRA21-1 levels after administration increased compared to before the administration. There was no association between the CYFRA21-1 level and the result of treatment response using modified Response Evaluation Criteria in Solid Tumors (mRECIST) 12 weeks after the administration. Univariate analysis identified a maximum intrahepatic tumor diameter of 70 mm or more, extrahepatic metastasis, baseline alpha-fetoprotein (AFP) ≥ 2000 ng/mL, baseline AFP-L3 index ≥ 15%, baseline des-gamma-carboxy prothrombin (DCP) ≥ 1000 mAU/mL, baseline CYFRA21-1 > 3.5 ng/mL, 12-week mRECIST progressive disease (PD), 12-week DCP ratio ≥ 4, 12-week CYFRA21-1 ratio ≥ 2, administration period less than 12 weeks, ALBI grade 3 at PD, and no additional treatment after discontinuation of SOR/LEN as prognostic factors. Multivariate analysis revealed that AFP-L3 index ≥ 15%, 12-week mRECIST PD, 12-week DCP ratio ≥ 4, 12-week CYFRA21-1 ratio ≥ 2, administration period less than 12 weeks, and no additional treatment after discontinuation of SOR/LEN were independent factors. Conclusions: Patients with a high CYFRA21-1 level at baseline tend to have poor prognosis, and patients with a high CYFRA21-1 ratio 12 weeks after administration have poor prognosis. Serum CYFRA21-1 measurement may have additional effects on prognostic prediction, and it may be necessary to pay close attention to the transition to the next HCC treatment in cases whose CYFRA21-1 level is high.

Gadoxetate-enhanced MRI Features of Proliferative Hepatocellular Carcinoma Are Prognostic after Surgery

Background Hepatocellular carcinomas (HCCs) are heterogeneous neoplasms, and the prognosis varies based on the subtype. Two broad molecular classes of HCC have been proposed: a proliferative and a nonproliferative class. Purpose To evaluate the gadoxetate-enhanced MRI findings of the proliferative class HCC and its prognostic significance after surgery. Materials and Methods This retrospective cohort study evaluated patients with surgically resected treatment-naive single HCC (≤5 cm) who underwent hepatic resection from January 2010 through February 2013 and preoperative gadoxetate-enhanced MRI. A Cox proportional hazards model was used to determine the predictive factors for overall survival (OS), intrahepatic distant recurrence, and extrahepatic metastasis (EM). The mean follow-up period was 75.5 months ± 30.2 (standard deviation). Multivariable logistic regression was performed to determine factors associated with proliferative class HCC. Results A total of 158 patients (mean age, 57 years ± 11; 128 men and 30 women) were evaluated. Forty-two of the 158 HCCs (26.6%) were proliferative class HCCs (17 macrotrabecular-massive HCCs, 14 keratin 19-positive HCCs, 10 scirrhous HCCs, and one sarcomatoid HCC). The proliferative class was associated with worse OS (hazard ratio [HR], 3.1; 95% CI: 1.5, 6.0; P = .01) and higher rates of intrahepatic distant recurrence (HR, 1.83; 95% CI: 1.1, 2.9; P = .01) and EM (HR, 9.97; 95% CI: 3.2, 31.4; P < .001). Rim arterial phase hyperenhancement (APHE) at gadoxetate-enhanced MRI (odds ratio [OR], 6.35; 95% CI: 1.9, 21.7; P = .01) and high serum α-fetoprotein (>100 ng/mL) (OR, 4.18; 95% CI: 1.64, 10.7; P = .01) were independent predictors for proliferative HCC. The presence of rim APHE was associated with poor OS (HR, 2.4; 95% CI: 1.2, 4.9; P = .02) and higher rates of EM (HR, 7.4; 95% CI: 2.5, 21.7; P < .01). Conclusion The proliferative class of hepatocellular carcinoma (HCC) is an independent factor for poor overall survival with increased rates of intrahepatic and extrahepatic metastasis. Rim arterial phase hyperenhancement at gadoxetate-enhanced MRI may help to identify proliferative class HCC and predict poor overall survival and an increased incidence of extrahepatic metastasis. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Krinsky and Shanbhogue in this issue.

Immunological Microenvironment Predicts the Survival of the Patients with Hepatocellular Carcinoma Treated with Anti-PD-1 Antibody

INTRODUCTION

Although immune checkpoint inhibitors (ICIs) have been considered as promising agents for the treatment of advanced hepatocellular carcinoma (HCC), previous clinical trials revealed that the response to anti-programmed cell death protein 1 (anti-PD-1) monotherapy was as low as 20%. Identifying subgroups that respond well to ICIs is clinically important. Here, we studied the prognostic factors for anti-PD-1 antibody treatment based on the molecular and immunological features of HCC.

METHODS

Patients who were administered anti-PD1 antibody for advanced HCC at Kindai University Hospital were included. Clinicopathological backgrounds and antitumor responses were examined in 34 cases where tumor tissues before treatment were available. Transcriptome analysis was performed using 40 HCC samples obtained from surgical resection, and immune status was compared between 20 HCCs with activating mutations in β-catenin and those without the mutations using transcriptome-based immunogram.

RESULTS

Univariate analysis showed that the disease control rate was significantly better in patients with α-fetoprotein < 400 ng/mL, negative for β-catenin/glutamate synthetase (GS) staining, high combined positive score (CPS) of programmed death-ligand 1 (PD-L1), and increased infiltration of CD8⁺ cells in tumor tissues. Among them, negative staining of β-catenin/GS, CPS of PD-L1 ≥ 1, and high degree of CD8⁺ tumor-infiltrating lymphocytes (TILs) were significantly associated with longer survival in both progression-free survival (PFS) and overall survival (OS). The combination of these factors well stratified the survival of the patients on anti-PD-1 antibody in both PFS and OS (p < 0.0001 and p = 0.0048 for PFS and OS, respectively). In addition, the immunogram revealed that tumor-carrying mutations in β-catenin showed downregulation of immune-related genes, especially in those related to priming and activation by dendritic cells, interferon-γ response, inhibitory molecules, and regulatory T cells.

DISCUSSION/CONCLUSION

The combined score including Wnt/β-catenin activation, CPS of PD-L1, and degree of CD8⁺ TILs in HCC is informative for predicting the response to ICI in HCC cases. Constitutive activation of β-catenin can induce an immune cold phenotype with downregulation of immune-related genes, and immunohistochemistry-based evaluation is beneficial for identifying the subgroup that shows a good response to ICI.

Hepatocellular Carcinomas: Towards a pathomolecular approach

Molecular analysis of primary liver malignancies has provided a refinement of the pathological diagnosis of this entity and the identification of an increasing number of tumor subtypes of hepatocellular proliferation, either malignant (hepatocellular carcinomas) or benign (hepatocellular adenomas). Besides the diagnosis, a combined pathomolecular approach can also provide further insights into patient prognosis, and help select patients who can benefit from targeted therapies. Hepatocellular carcinomas define a heterogeneous group of malignant hepatocellular proliferation at various levels: macroscopic, histological and molecular. While most carcinomas occur in patients with chronic liver diseases and advanced fibrosis in the background liver, some arise from the malignant transformation of a pre-existing hepatocellular adenoma. TERT promoter mutations are the most frequent genomic alterations observed in the process of malignancy, and they occur early in the process of liver carcinogenesis. Overall, a more active biopsy strategy should be considered a key step in the management of patients with HCC.

Application of Immunohistochemistry in the Pathological Diagnosis of Liver Tumors

Although radiological diagnostics have been progressing, pathological diagnosis remains the most reliable method for diagnosing liver tumors. In some cases, definite pathological diagnosis cannot be obtained by histological evaluation alone, especially when the sample is a small biopsy; in such cases, immunohistochemical staining is very useful. Immunohistochemistry is the most frequently used technique for molecular pathological diagnosis due to its broad application, ease of performance and evaluation, and reasonable cost. The results occasionally reflect specific genetic mutations. The immunohistochemical markers of hepatocellular carcinoma include those of hepatocellular differentiation—such as hepatocyte paraffin 1 and arginase-1—and those of malignant hepatocytes—such as glypican-3, heat shock protein 70, and glutamine synthetase (GS). To classify the subtypes of hepatocellular adenoma, examination of several immunohistochemical markers, such as liver fatty acid-binding protein, GS, and serum amyloid A, is indispensable. Immunohistochemical staining for GS is also important for the diagnosis of focal nodular hyperplasia. The representative immunohistochemical markers of intrahepatic cholangiocarcinoma include cytokeratin (CK) 7 and CK19. In this article, we provide an overview of the application of immunohistochemistry in the pathological diagnosis of liver tumors referring to the association with genetic alterations. Furthermore, we aimed to explain the practical points in the differential diagnosis of liver tumors by immunohistochemical staining.

The strength of cytomorphology and efficacy of immuno-cytochemistry in distinguishing hepatocellular carcinoma from its mimics on fine-needle aspiration cytology

BACKGROUND

Cytomorphologic distinction of hepatocellular carcinoma (HCC) from its mimics on fine-needle aspiration cytology (FNAC) is often problematic. The present study evaluates the strength of cytomorphology and the utility of an immuno-panel of arginase-1, glypican-3, HepPar-1, thyroid transcription factor (TTF-1) and CK-19 in resolving this diagnostic issue.

METHODS

FNAC features of 71 nodular hepatic lesions were studied with an immunocyto/ histochemical (ICC/IHC) panel of arginase-1, glypican-3, HepPar-1, TTF-1 taking 10% positivity as "cut-off." Cytomorpholologic diagnoses were compared with diagnoses made on combined cytomorphologic and ICC/IHC approach.

RESULTS

Of 71 cases, 32, 10 and 29 had histopathologic, cell block and clinico-radiologic correlation respectively with 55 metastatic adenocarcinomas (MAC), 13 HCCs and one case each of hepatic adenoma (HA), cirrhotic nodule (CN) and intrahepatic cholangiocarcinoma (CC). Cytoplasmic positivity of HepPar-1 and glypican-3 were noted in 11/13 and 8/13 HCCs respectively; while only 3/13 and 1/13 HCCs revealed cytoplasmic positivity for arginase-1 and TTF-1 respectively. Benign hepatic lesions were negative for glypican-3 and TTF-1, but expressed both arginase-1and HepPar-1. Twenty-one of 55 MACs and the lone case of CC were positive for CK-19; however, all MACs and CC cases were negative for HepPar-1, arginase-1, glypican-3 and TTF-1. The immune-panel had sensitivity, specificity and diagnostic accuracy of 100%, 88.9% and 90.6%, respectively, for differentiating HCC from its morphologic mimics.

CONCLUSION

Though a meticulous cytologic evaluation in conjunction with clinicoradiologic profile helps in distinguishing HCC from its benign and malignant mimics; an immunopanel of arginase-1, glypican-3, HepPar-1, TTF-1 and CK-19 drastically improves the diagnostic accuracy.

Pathologic and molecular features of hepatocellular carcinoma: An update

Morphological diversity and several new distinct pathologic subtypes of hepatocellular carcinoma (HCC) are now well-recognized. Recent advances in tumor genomics and transcriptomics have identified several recurrent somatic/genetic alterations that are closely related with histomorphological subtypes and have therefore, greatly improved our understanding of HCC pathogenesis. Pathologic subtyping allows for a diagnosis which is clinically helpful and can have important implication in patient prognostication as some of these subtypes are extremely aggressive with vascular invasion, early recurrence, and worst outcomes. Several targeted treatments are now being considered in HCC, and the reporting of subtypes may be quite useful for personalized therapeutic purpose. This manuscript reviews the recently identified histomorphological subtypes and molecular alterations in HCC.

Circulating Tumor Cells Undergoing the Epithelial-Mesenchymal Transition: Influence on Prognosis in Cytokeratin 19-Positive Hepatocellular Carcinoma

Purpose

The purpose of this study was to elucidate the relationship between cytokeratin 19 (CK19) expression and levels of circulating tumor cells (CTCs) in preoperative peripheral blood of patients with hepatocellular carcinoma (HCC), and the potential influence of that relationship on prognosis.

Patients and Methods

CanPatrol™ CTC-enrichment technique and in situ hybridization (ISH) were used to enrich and classify CTCs undergoing the epithelial–mesenchymal transition (EMT) from blood samples of 105 HCC patients. CK19 immunohistochemistry staining was performed on HCC tissues and compared with demographic and clinical data.

Results

In total, 27 of 105 (25.7%) HCC patients were CK19-positive. CK19-positive patients had significantly lower median tumor-free survival (TFS) than CK19-negative patients (5 vs 10 months, P = 0.047). In total, 98 (93.3%) patients showed pre-surgery peripheral blood CTCs (range: 0–76, median: 6), and 57 of 105 (54.3%) patients displayed CTC counts ≥6. Furthermore, CK19-positive patients with CTC count ≥6 showed significantly higher percentage than CK19-negative ones (77.8% vs 46.2%, P = 0.004). CK19-positive patients showed a significantly higher proportion of mesenchymal CTCs among CTCs undergoing EMT than CK19-negative patients (mean rank: 62.28 vs 49.79, P = 0.046). We also found that CK19-positive patients with high CTC count showed significantly shorter median tumor-free survival than CK19-negative patients with low CTC count (5 vs 16 months, P = 0.039).

Conclusion

High CTC count and high percentage of mesenchymal CTCs are closely related to the expression of CK19, which is associated with poor prognosis in HCC patients.

An overview of hepatocellular carcinoma with atypical enhancement pattern: spectrum of magnetic resonance imaging findings with pathologic correlation

BACKGROUND

In the setting of cirrhotic liver, the diagnosis of hepatocellular carcinoma (HCC) is straightforward when typical imaging findings consisting of arterial hypervascularity followed by portal-venous washout are present in nodules larger than 1 cm. However, due to the complexity of hepatocarcinogenesis, not all HCCs present with typical vascular behaviour. Atypical forms such as hypervascular HCC without washout, isovascular or even hypovascular HCC can pose diagnostic dilemmas. In such cases, it is important to consider also the appearance of the nodules on diffusion-weighted imaging and hepatobiliary phase. In this regard, diffusion restriction and hypointensity on hepatobiliary phase are suggestive of malignancy. If both findings are present in hypervascular lesion without washout, or even in iso- or hypovascular lesion in cirrhotic liver, HCC should be considered. Moreover, other ancillary imaging findings such as the presence of the capsule, fat content, signal intensity on T2-weighted image favour the diagnosis of HCC. Another form of atypical HCCs are lesions which show hyperintensity on hepatobiliary phase. Therefore, the aim of the present study was to provide an overview of HCCs with atypical enhancement pattern, and focus on their magnetic resonance imaging (MRI) features.

CONCLUSIONS

In order to correctly characterize atypical HCC lesions in cirrhotic liver it is important to consider not only vascular behaviour of the nodule, but also ancillary MRI features, such as diffusion restriction, hepatobiliary phase hypointensity, and T2-weighted hyperintensity. Fat content, corona enhancement, mosaic architecture are other MRI feautures which favour the diagnosis of HCC even in the absence of typical vascular profile.

Hyperpolyploidization of hepatocyte initiates preneoplastic lesion formation in the liver

Hepatocellular carcinoma (HCC) is the most predominant primary malignancy in the liver. Genotoxic and genetic models have revealed that HCC cells are derived from hepatocytes, but where the critical region for tumor foci emergence is and how this transformation occurs are still unclear. Here, hyperpolyploidization of hepatocytes around the centrilobular (CL) region is demonstrated to be closely linked with the development of HCC cells after diethylnitrosamine treatment. We identify the CL region as a dominant lobule for accumulation of hyperpolyploid hepatocytes and preneoplastic tumor foci formation. We also demonstrate that upregulation of Aurkb plays a critical role in promoting hyperpolyploidization. Increase of AURKB phosphorylation is detected on the midbody during cytokinesis, causing abscission failure and hyperpolyploidization. Pharmacological inhibition of AURKB dramatically reduces nucleus size and tumor foci number surrounding the CL region in diethylnitrosamine-treated liver. Our work reveals an intimate molecular link between pathological hyperpolyploidy of CL hepatocytes and transformation into HCC cells.

Immune microenvironment of hepatocellular carcinoma, intrahepatic cholangiocarcinoma and liver metastasis of colorectal adenocarcinoma: Relationship with histopathological and molecular classifications

Tumor tissue is composed of tumor cells and tumor stroma. Tumor stroma contains various immune cells and non-immune stromal cells, forming a complex tumor microenvironment which plays pivotal roles in regulating tumor growth. Recent successes in immunotherapies against tumors, including immune checkpoint inhibitors, have further raised interests in the immune microenvironment of liver carcinoma. The immune microenvironment of tumors is formed because of interactions among tumor cells, immune cells and non-immune stromal cells, including fibroblasts and endothelial cells. Different patterns of immune microenvironment are observed among different tumor subtypes, and their clinicopathological significance and intertumor/intratumor heterogeneity are being intensively studied. Here, we review the immune microenvironment of hepatocellular carcinoma, intrahepatic cholangiocarcinoma and liver metastasis of colorectal adenocarcinoma, focusing on its histopathological appearance, clinicopathological significance, and relationship with histological and molecular classifications. Understanding the comprehensive histopathological picture of a tumor immune microenvironment, in addition to molecular and genetic approaches, will further potentiate the effort for precision medicine in the era of tumor-targeting immunotherapy.