Decreased intratumoral arteries reflect portal tract destruction and aggressive characteristics in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma with arterial phase hyperenhancement and specialized tumor microenvironment associated with good prognosis after radical resection: A single-center retrospective study

BACKGROUND

This single-center retrospective study aimed to clarify the clinical and pathologic background of mass-forming intrahepatic cholangiocarcinomas.

METHODS

A total of 53 patients with mass-forming intrahepatic cholangiocarcinomas were selected from 2007 to 2021 and analyzed based on several parameters, including the preoperative computed tomography pattern (enhancement in the arterial phase of dynamic contrast-enhanced computed tomography), clinical data, and tumor microenvironment evaluated by immunohistochemistry. The hyperenhancement (n = 13) and hypoenhancement (n = 40) groups were defined using the 50% cutoff of tumors with higher attenuation than the liver parenchyma.

RESULTS

The hyperenhancement group was characterized by a better overall survival than the hypoenhancement group (5-year survival: 86% vs 27%, respectively; P < .001) and by a higher infiltration of peritumoral (92% vs 58%; P = .020) and intratumoral CD3-positive T lymphocytes (85% vs 35%; P = .002). Conversely, the hypoenhancement group was characterized by a higher infiltration versus peritumoral CD163-positive tumor-associated macrophages (60% vs 8%; P = .001), peritumoral pentraxin 3-positive tumor-associated macrophages (50% vs 15%; P = .024), and intratumoral α-smooth muscle actin-positive cancer-associated fibroblasts (15% vs 68%; P = .001). A multiple regression analysis was performed to predict overall survival from the microenvironment, and the independent poor predictor factors were low intratumoral CD3-positive T lymphocytes (hazard ratio = 2.75), high peritumoral (hazard ratio = 2.38), and intratumoral CD163-positive tumor-associated macrophages (hazard ratio = 2.81) (all P values < 0.05).

CONCLUSION

Compared with hypovascular, hypervascular mass-forming intrahepatic cholangiocarcinomas have better tumor immunity and prognosis.

Subtype prediction of intrahepatic cholangiocarcinoma using dynamic contrast-enhanced ultrasound

OBJECTIVE

The study aimed to investigate the predictive value of dynamic contrast-enhanced ultrasound (DCE-US) in differentiating small-duct (SD) and large-duct (LD) types of intrahepatic cholangiocarcinoma (ICC).

METHODS

This study retrospectively enrolled 110 patients with pathologically confirmed ICC lesions who were subject to preoperative contrast-enhanced ultrasound (CEUS) examinations between January 2022 and February 2023. Patients were further classified according to the subtype: SD-type and LD-type, and an optimal predictive model was established and validated using the above pilot cohort. The test cohort, consisting of 48 patients prospectively enrolled from March 2023 to September 2023, was evaluated.

RESULTS

In the pilot cohort, compared with SD-type ICCs, more LD-type ICCs showed elevated carcinoembryonic antigen (p < 0.001), carbohydrate antigen 19-9 (p = 0.004), ill-defined margin (p = 0.018), intrahepatic bile duct dilation (p < 0.001). Among DCE-US quantitative parameters, the wash-out area under the curve (WoAUC), wash-in and wash-out area under the curve (WiWoAUC), and fall time (FT) at the margin of lesions were higher in the SD-type group (all p < 0.05). Meanwhile, the mean transit time (mTT) and wash-out rate (WoR) at the margin of the lesion were higher in the LD-type group (p = 0.041 and 0.007, respectively). Logistic regression analysis showed that intrahepatic bile duct dilation, mTT, and WoR were significant predictive factors for predicting ICC subtypes, and the AUC of the predictive model achieved 0.833 in the test cohort.

CONCLUSIONS

Preoperative DCE-US has the potential to become a novel complementary method for predicting the pathological subtype of ICC.

CRITICAL RELEVANCE STATEMENT

DCE-US has the potential to assess the subtypes of ICC lesions quantitatively and preoperatively, which allows for more accurate and objective differential diagnoses, and more appropriate treatments and follow-up or additional examination strategies for the two subtypes.

KEY POINTS

Preoperative determination of intrahepatic cholangiocarcinoma (ICC) subtype aids in surgical decision-making. Quantitative parameters from dynamic contrast-enhanced US (DCE-US) allow for the prediction of the ICC subtype. DCE-US-based imaging has the potential to become a novel complementary method for predicting ICC subtypes.

Combined arterial and delayed enhancement patterns of MRI assist in prognostic prediction for intrahepatic mass-forming cholangiocarcinoma (IMCC)

OBJECTIVES

This study valued MR delayed enhancement pattern in predicting postoperative prognosis of intrahepatic mass-forming cholangiocarcinoma (IMCC).

METHODS

From 2011 to 2015, 231 patients of IMCC underwent DCE-MRI preoperatively. Enhancement patterns and MRI characteristics were evaluated. Recurrence and mortality data were compared among IMCCs with different enhancement patterns. Prognostic factor analysis was performed using preoperative and postoperative clinical-pathologic factors, as well as imaging findings.

RESULTS

Fifty-six (24.2%), 142 (61.5%) and 33 (14.3%) tumors showed hypo, peripheral rim and diffuse hyper enhancement in AP. Fifty-six (24.2%), 81 (35.1%) and 94 (40.7%) tumors showed hypo, heterogeneous and uniform enhancement in DP. Patients with arterial diffuse hyper enhancement or delayed uniform enhancement IMCCs had lower preoperative CA19-9 levels, smaller tumor sizes and minor operations than the rest patients (p < 0.05) and they were less associated with lymph nodes metastasis, vascular invasion, necrosis or poor tumor differentiation (p < 0.05), therefore with higher overall and disease-free survival rates (p < 0.05). The combination of AP and DP increased the detection rate of patients with good prognosis in the arterial rim enhancement group. Multivariate analysis revealed the delayed enhancement pattern (hypo HR = 6.304/10.028 for DFS/OS; heterogenous HR = 4.579/4.972 for DFS/OS), multitude of lesions (HR = 1.6/1.5 for DFS/OS) and tumor sizes (HR = 1.6 for DFS) were independent prognostic factors.

CONCLUSIONS

The uniform enhancement pattern in delayed MRI was an independent optimal prognostic factor for IMCCs and increased the detection rate of patients with good prognosis compared to the arterial diffuse hyper enhancement pattern.

Diversity in cell differentiation, histology, phenotype and vasculature of mass-forming intrahepatic cholangiocarcinomas

AIMS

Mass-forming intrahepatic cholangiocarcinomas (MF-iCCAs), involving small bile ducts, bile ductules or canals of Hering, remain treated as a single entity. We aimed to examine the diversity in histology, phenotype and tumour vasculature of MF-iCCAs.

METHODS AND RESULTS

Based on morphology and immunophenotype, we classified MF-iCCAs into small bile duct (SBD), cholangiolocarcinoma (CLC), ductal plate malformation (DPM) and hepatocellular carcinoma (HCC)-like subtypes. Genetic correlations among the histological subtypes were examined by multi-region tumour sequencing. Vasculatures and other clinicopathological features were compared among tumour groups with various proportions of the histological subtypes in 62 MF-iCCAs. Cases of pure SBD, CLC, DPM and HCC-like subtypes numbered 18 (29%), seven (11.3%), none (0%) and two (3%), respectively; the remaining 35 (56.4%) cases comprised several components. Genetic alterations, isocitrate dehydrogenase (IDH)1/2, KRAS, TP53, polybromo-1 (PBRM1) and BRCA1-associated protein 1 (BAP1), were shared among SBD, CLC, DPM and hepatoid components within a tumour. We uncovered distinct vascularisation mechanisms among SBD, CLC and DPM subtypes with a prominent vessel co-option in CLC tumours. iCCA with a DPM pattern had the highest vascular densities (mean microvascular density,140/mm² ; arterial vessel density, 18.3/mm² ). Increased CLC component was correlated with longer overall survival time (r = 0.44, P = 0.006). Pure SBD tumours had a lower 5-year overall survival rate compared with MF-iCCA with CLC pattern (30.5 versus 72.4%, P = 0.011).

CONCLUSIONS

MF-iCCAs comprise four histological subtypes. Given their sharing some driver gene alterations, indicating they can have a common cell origin, SBD, CLC and DPM subtypes, however, differ in cell differentiation, histology, phenotype or tumour vasculature.

Prognostic impact of tumor microvessels in intrahepatic cholangiocarcinoma: association with tumor-infiltrating lymphocytes

Tumor microvessel density (MVD) is a prognostic factor for patients with intrahepatic cholangiocarcinoma (ICC). Tumor-infiltrating lymphocytes (TILs) are also key components of the tumor microenvironment that play important roles in ICC progression. This study aimed to clarify the relationships between the MVD and immune status and prognosis in patients with ICC. Immunohistochemical staining for cluster of differentiation 34 (CD34), cluster of differentiation 8 (CD8), forkhead box protein P3 (Foxp3), and programmed death-ligand 1 (PD-L1) was performed. The relationships between the MVD and clinicopathological characteristics and outcomes were analyzed. Additionally, the correlations between the MVD, CD8+ and Foxp3+ TIL counts, and PD-L1 expression were evaluated. One hundred ICC patients were classified into high (n = 50) and low (n = 50) MVD groups. The serum platelet and carbohydrate antigen 19-9 levels were higher in the low MVD group than in the high MVD group (P = 0.017 and P = 0.008, respectively). The low MVD group showed a significantly larger tumor size (P = 0.016), more frequent microvascular invasion (P = 0.001), and a higher rate of intrahepatic (P = 0.023) and lymph node (P < 0.001) metastasis than the high MVD group. Moreover, the MVD showed a high positive correlation with CD8+ TILs (r = 0.754, P < 0.001) and a negative correlation with Foxp3+ TILs (r = -0.302, P = 0.003). In contrast, no significant correlation was observed between the MVD and PD-L1 expression in cancer cells (P = 0.817). Patients with low MVDs had a significantly worse prognosis than those with high MVDs. Furthermore, multivariable analyses revealed that a low MVD influenced recurrence-free survival. A decreased intratumoral MVD might predict ICC patient outcomes. Tumor microvessels might be associated with ICC progression, possibly by altering TIL recruitment.

Short- and Long-Term Outcomes of Liver Resection for Intrahepatic Cholangiocarcinoma Associated with the Metabolic Syndrome

BACKGROUND

While the metabolic syndrome (MS) is being recognized as an important risk factor for intrahepatic cholangiocarcinoma (ICC), the outcomes of liver resection in this context remain poorly described. This study aims to report the short- and long-term results of hepatectomy for patients with MS as risk factor for the development of ICC (MS+).

METHODS

All patients undergoing hepatectomy for ICC between 2000 and 2016 at a single center were retrospectively analyzed. The perioperative outcomes of MS+ and ICC patients without MS (MS-) were compared.

RESULTS

Among 115 resected ICC patients, 40 (34.8%) were MS+ and 75 (65.2%) were MS-. MS+ exhibited an increased Charlson comorbidity index (5 ± 2 vs. 2 ± 2, p < 0.001) than MS- patients. While operative characteristics did not differ significantly between the 2 groups, MS+ experienced higher rate of major complications (62.5 vs. 29.3%, p = 0.001). On multivariate analysis, MS+ was an independent risk factor of major complication (HR 2.86, 95% CI 1.07-7.60, p = 0.036) and major cardiorespiratory complication (HR 4.35, 95% CI 1.50-12.62, p = 0.007). Pathological analysis revealed that MS+ displayed higher rates of non-alcoholic fatty liver disease (60.0 vs. 31.1%, p = 0.003) and non-alcoholic steatohepatitis (25 vs. 5.4%, p = 0.005). MS+ was independently associated with decreased risk of recurrence (HR 0.47, 95% CI 0.26-0.85, p = 0.001).

CONCLUSIONS

MS+ accounts for 35% of resected ICC patients. The existence of significant cardiovascular comorbidities increases postoperative morbidity and requires specific management.

Microvessel density and angiogenesis in primary hepatic malignancies: Differential expression of CD31 and VEGFR-2 in hepatocellular carcinoma and intrahepatic cholangiocarcinoma

BACKGROUND

Microvessel density is an indicator of tumor-driven neoangiogenesis. Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) have distinct vascular patterns, which are also reflected in their imaging characteristics. Since a significant proportion of HCC are treated without biopsy confirmation, it is essential to discriminate HCC and ICC radiologically. The aim of our study was therefore to compare microvessel density and expression of VEGFR-2 in HCC and ICC, since these data may ultimately help us to better understand their imaging characteristics. Whereas CD31 documents vessel density, VEGFR-2 expression is an indicator of tumor-related neoangiogenesis.

METHODS

CD31 and VEGFR-2 expressing microvessels were quantified on tissue microarrays of 95 resection specimens of HCC and 47 cases of ICC. Microvessel density was evaluated by counting immuno-reactive vascular structures both within the tumor and adjacent liver control tissue, respectively. Further 16 cases of ICC were immunostained for CD31 and VEGFR-2 on full sections.

RESULTS

The frequency of VEGFR-2 (46.2/HPF; range 0-150) and CD31 (61.2/HPF; range 2.6-140) expressing vascular structures was significantly increased in HCC compared to adjacent liver parenchyma (VEGFR-2 33.3/HPF, range 0-87, CD31 21.4/HPF, range 0-78, both p < 0,001). ICC revealed significantly less VEGFR2-positive microvessels (15.4/HPF; range 2-77) compared to matched control tissue (42.3/HPF; range 4.6-109), whereas microvessel density with CD31 was comparable between ICC and adjacent liver (32.1/HPF; range 5.3-78 versus 28.0/HPF; range 5.3-57; p = 0.89). In ICC, the tumor-to-normal microvessel density ratio was 0.38 for VEGFR-2 and 1.24 for CD31. These ratios were nearly identical (VEGFR: 0.38; CD31: 0,97) for the 16 cases of ICC studied on whole sections, confirming the validity of the TMA approach. In contrast, ratios of VEGFR-2 and CD31 in HCC vs. adjacent liver were significantly higher (VEGFR: 2.23; CD31: 6.57). Expression of VEGFR-2 by tumor cells was not observed in any of the cases.

CONCLUSIONS

HCC and ICC differ significantly in their microvessel density, confirming the hypovascular nature of ICC as compared to the hypervascularity of HCC. Of note, inverse tumor-to-normal ratios of microvascular VEGFR-2 expression between the two neoplasms indicate distinct features of neoangiogenesis. Whether these differences can be exploited for improvements in imaging of hepatic tumors and may play a role for anti-angiogenic treatment strategies requires further studies.

Intrahepatic Mass-Forming Cholangiocarcinoma: Relationship Between Computed Tomography Characteristics and Histological Subtypes

OBJECTIVE

The aim of this study was to determine the value of multi-detector row computed tomography (MDCT) in differentiating the small-duct (SD) and large-duct (LD) types of intrahepatic mass-forming cholangiocarcinomas (IMCCs) and predicting patient prognosis.

METHODS

The 4-phase MDCT image findings of 82 patients with surgically confirmed IMCCs (60 SD-type and 22 LD-type IMCCs) were compared between 2 types using univariate and multivariate analyses. Overall survival rates for 78 patients with available information were compared using the Kaplan-Meier method.

RESULTS

Arterial hyperenhancement, round or lobulated contour, and lack of bile duct encasement were significant MDCT features suggesting the SD type, and lymph node enlargement was significantly associated with the LD type (all P's < 0.05). The presence of those 3 SD-type-suggestive features (MDCT-suggested SD type) demonstrated high specificity (90.9% [20/22]) in differentiating the SD type. Patients of MDCT-suggested SD type without lymph node enlargement (n = 24) demonstrated significantly better overall survival than other groups.

CONCLUSIONS

Preoperative MDCT features of IMCCs can help differentiate the SD and LD types and predict patient prognosis.

Histopathological characteristics of hypervascular cholangiocellular carcinoma as an early stage of cholangiocellular carcinoma

AIM

Prognosis of hypervascular cholangiocellular carcinoma (h-CCC) is reportedly better than that of ordinary hypovascular CCC (o-CCC). The aim of this study is to clarify the histopathological characteristics of h-CCC.

METHODS

On the basis of the findings in the arterial phase of contrast-enhanced computed tomography, 16 cases of mass-forming-type CCC were divided into two groups (h-CCC, n = 8; o-CCC, n = 8). Areas of high (Area H-a) and low (Area H-b) attenuation in h-CCC cases and areas of low attenuation in o-CCC cases (Area O) were delineated. These areas were then evaluated histopathologically to determine the proportion of tumor cells, fibrous stroma, arterial vessel density, and immunohistochemical expression of Vascular endothelial growth factor; angiopoietin-2; cytokeratin 7, CK19, SOX9 and SOX17 genes; epithelial cell adhesion molecule; and the Bmi-1, Ki-67, epithelial membrane antigen and polyclonal carcinoembryonic antigen.

RESULTS

The areal ratio of tumor cells decreased and that of fibrous stroma increased in the following order: Area H-a, Area H-b and Area O. Values for AVD and neural cell adhesion molecule positivity rate were significantly higher in Area H-a than in Areas H-b or O. Expressions of vascular endothelial growth factor and angiopoietin-2 were significantly higher in Areas H-a and H-b than in Area O. The Ki-67 labeling index increased in the following order: Area H-a, Area H-b and Area O.

CONCLUSION

A high areal ratio of tumor cells and AVD as well as a high expression of stem cells and angiogenic markers were observed in cases of h-CCC, whereas the areal ratio of fibrous stroma and malignant potential were low. These results suggest that h-CCC may represent the early stage of CCC.

Pathogenesis and classification of intrahepatic cholangiocarcinoma: different characters of perihilar large duct type versus peripheral small duct type

Intrahepatic cholangiocarcinomas (ICCs) are made up of heterogenous carcinomas arising from different anatomical sites of the liver. Two types of candidate stem/progenitor cells of the biliary tree are postulated to exist at the peribiliary glands for large bile ducts and at the canals of Hering for small ducts and hepatocytes. According to the recent observations, ICCs can be subclassified into two types: tumors involving the large bile ducts comparable in size to the intrahepatic second branches and composed of a tubular or papillary component with tall columnar epithelium, and tumors involving the smaller duct than segmental branches and composed of small tubules with cuboidal epithelium. Perihilar large duct type ICCs can be interpreted as arising from large bile duct type ICCs, and peripheral small duct type ICCs may arise from small bile duct type or ductular type ICCs. Chronic biliary inflammation induces neoplastic change of the large bile ducts and thereby progression to the perihilar large duct type ICC, which can be grossly classified into periductal filtrating type ICC and intraductal growth type ICC, while chronic hepatitis or cirrhosis induces mass-forming peripheral small duct type ICC. The different morphological and molecular features, including stromal components and tumor vasculature, support the hypothesis that perihilar large duct type ICCs and peripheral small duct type ICCs arise from different backgrounds, have different carcinogenetic pathways, and exhibit different biologic behaviors.