Tumor-associated lymphangiogenesis correlates with lymph node metastases and prognosis in hilar cholangiocarcinoma

Histopathological growth pattern and vessel co-option in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) exhibits different blood imaging features and prognosis depending on histology. To clarity histopathological growth patterns (HGPs) and vascularization processes of iCCA, we collected 145 surgical specimens and histologically classified them into large bile duct (LBD) (20 cases), small bile duct (SBD) (54), cholangiolocarcinoma (CLC) (35), combined SBD-CLC (cSBD-CLC) (26), and ductal plate malformation (DPM) (10) (sub)types. According to the invasive pattern at the interface between tumor and adjacent background liver, HGPs were classified into desmoplastic, pushing, and replacing HGPs. Desmoplastic HGP predominated in LBD type (55.5%), while replacing HGP was common in CLC (82.9%) and cSBD-CLC (84.6%) subtypes. Desmoplastic HGP reflected angiogenesis, while replacing HGP showed vessel co-option in addition to angiogenesis. By evaluating microvessel density (MVD) using vascular markers, ELTD1 identified vessel co-option and angiogenesis, and ELTD1-positive MVD at invasive margin in replacing HGP was significantly higher than those in desmoplastic and pushing HGPs. REDD1, an angiogenesis-related marker, demonstrated preferably higher MVD in the tumor center than in other areas. iCCA (sub)types and HGPs were closely related to vessel co-option and immune-related factors (lymphatic vessels, lymphocytes, and neutrophils). In conclusion, HGPs and vascular mechanisms characterize iCCA (sub)types and vessel co-option linked to the immune microenvironment.

Tumor lymphangiogenesis index reveals the immune landscape and immunotherapy response in lung adenocarcinoma

Background

Lymphangiogenesis (LYM) has an important role in tumor progression and is strongly associated with tumor metastasis. However, the clinical application of LYM has not progressed as expected. The potential value of LYM needs to be further developed in lung adenocarcinoma (LUAD) patients.

Methods

The Sequencing data and clinical characteristics of LUAD patients were downloaded from The Cancer Genome Atlas and GEO databases. Multiple machine learning algorithms were used to screen feature genes and develop the LYM index. Immune cell infiltration, immune checkpoint expression, Tumor Immune Dysfunction and Exclusion (TIDE) algorithm and drug sensitivity analysis were used to explore the correlation of LYM index with immune profile and anti-tumor therapy.

Results

We screened four lymphangiogenic feature genes (PECAM1, TIMP1, CXCL5 and PDGFB) to construct LYM index based on multiple machine learning algorithms. We divided LUAD patients into the high LYM index group and the low LYM index group based on the median LYM index. LYM index is a risk factor for the prognosis of LUAD patients. In addition, there was a significant difference in immune profile between high LYM index and low LYM index groups. LUAD patients in the low LYM index group seemed to benefit more from immunotherapy based on the results of TIDE algorithm.

Conclusion

Overall, we confirmed that the LYM index is a prognostic risk factor and a valuable predictor of immunotherapy response in LUAD patients, which provides new evidence for the potential application of LYM.

Prognostic Role of the Intrahepatic Lymphatic System in Liver Cancer

Although several prognosticators, such as lymph node metastasis (LNM), were reported for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), the prognostic impact of intrahepatic lymphatic vessel invasion (LVI) in liver cancer has rarely been reported. We sought to clarify the prognostic impact of intrahepatic lymphatic system involvement in liver cancer. We systematically reviewed retrospective studies that described LVI and clinical outcomes of liver cancer and also included studies that investigated tumor-associated lymphangiogenesis. We conducted a meta-analysis using RevMan software (version 5.4.1; Cochrane Collaboration, Oxford, UK). The prognostic impact of intrahepatic LVI in HCC was not reported previously. However, tumor-associated lymphangiogenesis reportedly correlates with prognosis after HCC resection. The prognostic impact of intrahepatic LVI was reported severally for ICC and a meta-analysis showed that overall survival was poorer in patients with positive LVI than with negative LVI after resection of ICC. Lymphangiogenesis was also reported to predict unfavorable prognosis in ICC. Regarding colorectal liver metastases, LVI was identified as a poor prognosticator in a meta-analysis. A few reports showed correlations between LVI/lymphangiogenesis and LNM in liver cancer. LVI and lymphangiogenesis showed worse prognostic impacts for liver cancer than their absence, but further study is needed.

Lymphatics in Tumor Progression and Immunomodulation

The lymphatic system consists of a unidirectional hierarchy of vessels responsible for fluid homeostasis, lipid absorption, and the transport of immune cells and antigens to secondary lymphoid organs. In cancer, lymphatics play complex and heterogenous roles that can promote or inhibit tumor growth. While lymphatic proliferation and remodeling promote tumor dissemination, functional lymphatics are necessary for generating an effective immune response. Recent reports have noted lymphatic-dependent effects on the efficacy of immunotherapy. These findings suggest that the impact of lymphatic vessels on tumor progression is organ- and context-specific and that a greater understanding of the interaction of tumor cells, lymphatics, and the tumor microenvironment can unveil novel therapies.

Serosal invasion is a strong prognostic factor for hepatocellular carcinoma after hepatectomy

AIM

The clinical impact of serosal invasion by hepatocellular carcinoma (HCC) remains unclear. This study aimed to clarify the significance of serosal invasion as a prognostic factor for patients who underwent hepatectomy for HCC.

METHODS

This retrospective study investigated patients who underwent hepatectomy for HCC between October 2003 and September 2016 in Ehime University Hospital (Toon, Japan). A total of 161 cases were enrolled after excluding cases of concomitant distant metastasis, macroscopic tumor remnant, mixed HCC, and rehepatectomy. We classified these 161 patients into groups with serosal invasion detected (S[+]) and serosal invasion undetected (S[-]). We compared patient characteristics, perioperative data, pathological findings, and prognosis between S(+) and S(-) groups.

RESULTS

Serosal invasion was observed in 19 of the 161 patients (12%). The 5-year recurrence-free survival rate was lower for S(+) (13.0%) than for S(-) (28.7%, P = 0.006). The 5-year overall survival (OS) rate was lower for S(+) (24.7%) than for S(-) (63.9%, P < 0.001). Regarding OS, serosal invasion, preoperative α-fetoprotein value, presence of invasion to hepatic veins, and liver cirrhosis were independent predictors in multivariate analyses. The 3-year OS rate after recurrence was poorer in the S(+) group (22.9%) than in the S(-) group (49.7%, P = 0.001).

CONCLUSIONS

Serosal invasion was a strong predictor of worse outcomes after hepatectomy for HCC. Patients showing serosal invasion need close postoperative follow-up or consideration of adjuvant treatment.

Tumor-associated lymphangiogenesis predicts unfavorable prognosis of intrahepatic cholangiocarcinoma

Background

Tumor-associated lymphangiogenesis is considered significant in number of solid malignancies. However, its impact on prognosis of intrahepatic cholangiocarcinoma (ICC) after resection remains further confirmation. Herein, we conducted this study to evaluate prognostic impact of tumor-associated lymphangiogenesis in patients with ICC.

Methods

Extent of tumor-associated lymphangiogenesis of ICC was evaluated by quantifying microlymphatic vessel density (MLVD) from immunohistochemical staining of a lymphatic endothelial-specific antibody (podoplanin). Clinicopathological characteristics were comprehensively analyzed to identify MLVD-associated factors. The patients were stratified into high and low MLVD groups according to the distinctive correlation between the MLVD and overall survival using the Spearman’s correlation test. Kaplan-Meier estimation was performed to confirm prognostic impact of MLVD in patients with ICC. Univariate and multivariate analyses were performed using the Cox proportional hazard model.

Results

The MLVD between 4 to 12 counts showed inverse proportion to the overall survival (Spearman’s r = − 0.66; 95% confidence interval [CI], − 0.82 to − 0.39; p <  0.0001), which was set as a cut-off for the high MLVD group, whereas the MLVD between 13 to 25 showed no correlation to the overall survival (r = − 0.11; 95% CI, − 0.38 to 0.19; p = 0.4791). The high MLVD group showed more frequent lymph node metastasis (p <  0.001) and were more likely to suffer from recurrence of the tumor compared to the low MLVD group (p <  0.001). The high MLVD was found to be independently associated with reduced overall and recurrence-free survival. The 5-year overall survival of the patients with high MLVD was significantly lower compared to those with low MLVD (0% vs 48%).

Conclusions

Our study reveals that tumor-associated lymphangiogenesis is significantly associated with increased lymphatic metastasis, recurrence of the tumor, and reduced overall survival in patients with ICC, thus providing guidance when estimating postresection prognosis.

The deleterious interplay between tumor epithelia and stroma in cholangiocarcinoma

Prognosis of cholangiocarcinoma, a devastating liver epithelial malignancy characterized by early invasiveness, remains very dismal, though its incidence has been steadily increasing. Evidence is mounting that in cholangiocarcinoma, tumor epithelial cells establish an intricate web of mutual interactions with multiple stromal components, largely determining the pervasive behavior of the tumor. The main cellular components of the tumor microenvironment (i.e. myofibroblasts, macrophages, lymphatic endothelial cells), which has been recently termed as 'tumor reactive stroma', are recruited and activated by neoplastic cells, and in turn, deleteriously mold tumor behavior by releasing a huge variety of paracrine signals, including cyto/chemokines, growth factors, morphogens and proteinases. An abnormally remodeled and stiff extracellular matrix favors and supports these cell interactions. Although the mechanisms responsible for the generation of tumor reactive stroma are largely uncertain, hypoxia presumably plays a central role. In this review, we will dissect the intimate relationship among the different cell elements cooperating within this complex 'ecosystem', with the ultimate goal to pave the way for a deeper understanding of the mechanisms underlying cholangiocarcinoma aggressiveness, and possibly, to foster the development of innovative, combinatorial therapies aimed at halting tumor progression. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

Tumor reactive stroma in cholangiocarcinoma: The fuel behind cancer aggressiveness

Cholangiocarcinoma (CCA) is a highly aggressive epithelial malignancy still carrying a dismal prognosis, owing to early lymph node metastatic dissemination and striking resistance to conventional chemotherapy. Although mechanisms underpinning CCA progression are still a conundrum, it is now increasingly recognized that the desmoplastic microenvironment developing in conjunction with biliary carcinogenesis, recently renamed tumor reactive stroma (TRS), behaves as a paramount tumor-promoting driver. Indeed, once being recruited, activated and dangerously co-opted by neoplastic cells, the cellular components of the TRS (myofibroblasts, macrophages, endothelial cells and mesenchymal stem cells) continuously rekindle malignancy by secreting a huge variety of soluble factors (cyto/chemokines, growth factors, morphogens and proteinases). Furthermore, these factors are long-term stored within an abnormally remodeled extracellular matrix (ECM), which in turn can deleteriously mold cancer cell behavior. In this review, we will highlight evidence for the active role played by reactive stromal cells (as well as by the TRS-associated ECM) in CCA progression, including an overview of the most relevant TRS-derived signals possibly fueling CCA cell aggressiveness. Hopefully, a deeper knowledge of the paracrine communications reciprocally exchanged between cancer and stromal cells will steer the development of innovative, combinatorial therapies, which can finally hinder the progression of CCA, as well as of other cancer types with abundant TRS, such as pancreatic and breast carcinomas.

Inhibition of the apelin/apelin receptor axis decreases cholangiocarcinoma growth

PURPOSE

Cholangiocarcinoma (CCA) is a malignancy of the biliary epithelium that is associated with low five-year survival. The apelin receptor (APLNR), which is activated by the apelin peptide, has not been studied in CCA. The purpose of this study is to determine if inhibition of the apelin/APLNR axis can inhibit CCA growth.

METHODS

Immunohistochemistry, rtPCR, immunofluorescence, flow cytometry, and ELISA was used to measure APLNR expression in human CCA cells and tissues. Mz-ChA-1 cells were treated with increasing concentrations of apelin and ML221, an APLNR antagonist. Expression of proliferative and angiogenic genes were measured via rtPCR. In vivo, Mz-ChA-1 cells were injected into the flanks of nu/nu mice, which were treated with ML221 (150 μg/kg) via tail vein injection.

RESULTS

Expression of the apelin/APLNR axis was increased in CCA. In vitro, CCA proliferation and angiogenesis was inhibited by ML221 treatment. ML221 treatment significantly decreased tumor growth in nu/nu mice.

CONCLUSION

The apelin/APLNR axis regulates CCA proliferation and angiogenesis. Inhibition of the apelin/APLNR axis decreases tumor growth in our xenograft model. Targeting APLNR signaling has the potential to serve as a novel, tumor directed therapy for CCA.

Regulation of migration and invasion by Toll-like receptor-9 signaling network in prostate cancer

Toll-like receptors (TLRs) play an important role in tumorigenesis and progress of prostate cancer. However, the function and mechanism of Toll-like receptor-9 (TLR9) in prostate cancer is not totally understood. Here, we found that high expression of TLR9 was associated with a higher probability of lymph node metastasis and poor prognosis. Further in vitro functional study verified that silence of TLR9 inhibited migration and invasion of PC-3 cells, indicating expression of TLR9 involving in the migration and invasion of cancer cells. The data of microarray exhibited silence of TLR9 induced 205 genes with larger than 2-fold changes in expression levels, including 164 genes down-regulated and 41 genes up-regulated. Functional Gene Ontology (GO) processes annotation demonstrated that the top three scores of molecular and cellular functions were regulation of programmed cell death, regulation of locomotion and response to calcium ion. TLR9 signaling network analysis of the migration and invasion related genes identified several genes, like matrix metallopeptidase 2 (MMP2), matrix metallopeptidase 9 (MMP9), chemokine receptor 4 (CXCR4) and interleukin 8 (IL8), formed the core interaction network based on their known biological relationships. A few genes, such as odontogenic ameloblast-associated protein (ODAM), claudin 2 (CLDN2), gap junction protein beta 1 (GJB1) and Rho-associated coiled-coil containing protein kinase 1 pseudogene 1 (ROCK1P1), so far have not been found to interact with the other genes. This study provided the foundation to discover the new molecular mechanism in signaling networks of invasion and metastasis in prostate cancer.

SPARCL1 is a novel predictor of tumor recurrence and survival in hilar cholangiocarcinoma

Secreted protein acidic and rich in cysteines-like protein 1 (SPARCL1) has been implicated in tumor initiation, formation, and progression of various cancers, yet its role in hilar cholangiocarcinoma remains largely uncharacterized. In the present study, tissue microarrays containing resected hilar cholangiocarcinoma specimens from 92 patients were used to evaluate the expression of SPARCL1 protein by immunohistochemistry (IHC). In vitro assays were used to determine the effect of SPARCL1 overexpression on cell growth and migration. Loss of SPARCL1 expression was observed in 46 (50.0 %) of the 92 primary tumors. SPARCL1 expression is inversely associated with poorly or undifferentiation specimens (P = 0.030) in addition to lymph node metastasis (P = 0.047). Survival analysis demonstrated that SPARCL1 is an independent factor in predicting the outcome of patients with hilar cholangiocarcinoma. SPARCL1 overexpression suppressed tumor cell migration in vitro by inhibiting MMP-9, MMP-2, Vimentin, and Fibronectin expression, whereas did not inhibit cell proliferation in vitro. Our results suggest that loss of SPARCL1 is involved in the tumorigenesis of hilar cholangiocarcinoma and may serve as a novel molecular biomarker for patients' outcome.

The DNA index as a prognostic tool in hilar cholangiocarcinoma

BACKGROUND AND OBJECTIVES

Due to the devastating prognosis of patients suffering from hilar cholangiocarcinoma (HCCA) valid prognostic factors are urgently needed to guide treatment decisions in a personalized concept. The aim of this study was to analyze the predictive value of the DNA index in a large single-center cohort of patients undergoing resection of HCCA.

METHODS

A total of 154 patients who underwent resection of HCCA were included in this prospective study. The DNA index was assessed by image cytometry of fresh tumor samples and correlated, as well as standard histopathological parameters, with patient survival.

RESULTS

The median DNA index was 1.61 ± 0.32. Univariate survival analysis identified eight parameters including DNA index, but not DNA ploidy as prognostic markers. In the Cox proportional hazard model DNA index (P = 0.021), tumor size (P = 0.029) and lymph nodes status (P = 0.039) could be shown to be independent predictors of patient survival.

CONCLUSION

The DNA index represents an independent prognostic marker in HCCA which is superior to most standard histopathological factors. Since the DNA index can be assessed not only post- but also preoperatively, it might be a potential tool in the preoperative decision-making process.

Role of surgery in cholangiocarcinoma: From resection to transplantation

The treatment of cholangiocarcinoma (CCA) represents a major challenge to modern medicine. Diagnostics and treatment modalities are complex and require close interdisciplinary work-up. However, surgical resection currently offers the only potentially curative treatment option. Improved peri-operative strategies as well as optimized surgical techniques have generated significantly increased survival chances for patients in recent years. Complete tumor resection is the key parameter to long-term survival. In spite of expanded surgical limits R0 resection cannot be achieved in some cases as parenchymal disease may limit the extent of resection. Although liver transplantation (LT) is not a standard therapy for CCA today, it may be an option in such selected cases. Protocols including neo-adjuvant radio-chemotherapy and staging-lymphadenectomy before LT have generated impressive results in the recent past. Since palliative options generate only short-term survival extension LT for CCA has lately been discussed more extensively after the procedure had been abandoned due to dismal survival data in the 1990-years. This review offers a comprehensive picture of the current surgical treatment option for cholangiocarcinoma.

A review on the use of confocal laser endomicroscopy in the bile duct

Background. Current methods to diagnose malignant biliary strictures are of low sensitivity. Probe-based confocal laser endomicroscopy (pCLE) is a new approach that can be used to evaluate in vivo histopathology of the GI tract. This paper is of studies evidencing pCLE's application in the diagnosis of indeterminate biliary strictures. Methods. This paper examined peer-reviewed studies conducted between January 2000 and November 2011. A PubMed search for relevant articles was performed using the following keywords:“pCLE”, “confocal”, “endomicroscopy”, “probe-based confocal laser endomicroscopy”, “and “bile duct”. Further individual review was done to assess the screened articles' relevance to the topic. Results. After individual review, 6 studies were included; with a cumulative sample size of 165, with 75 subjects identified as having a malignancy. These studies included tertiary care centers in Germany, France, and USA, including one multicenter trial. 3 studies assessed pCLE's specificity (range 67%–88%) ,sensitivity (range 83%–98), and accuracy (range 81%–86%). Conclusion. Confocal endomicroscopy is a novel and promising modality for the biliary tree. Further studies need to be conducted both to establish its usefulness for the diagnosis of indeterminate biliary strictures and to understand the histological meaning of the imaging patterns that are observed.

Identification of CD146 expression, angiogenesis, and lymphangiogenesis as progression, metastasis, and poor-prognosis related markers for gallbladder adenocarcinoma

Gallbladder cancers (GBC) are associated with high disease-specific mortality rates because of no means of early detection and effective therapies. In this study, we investigated CD146 expression, microvessel densities, and lymph vessel densities in 108 adenocarcinomas, 15 gallbladder polyps, 35 chronic cholecystitis tissues, and 46 peritumoral tissues using immunohistochemistry. We demonstrated that positive CD146 expression, and average microvessel and lymph vessel counts in gallbladder adenocarcinomas were significantly higher than those in peritumoral tissues, polyps, and chronic cholecystitis (ps < 0.01). Positive CD146 expression, and average microvessel and lymph vessel counts were also significantly lower in cases with well-differentiated adenocarcinoma, maximal tumor diameter <2 cm, no metastasis of lymph node, and no invasion of regional tissues than in cases with poorly differentiated adenocarcinoma, maximal tumor diameter ≥ 2 cm, metastasis in lymph nodes, and invasion of regional tissues (p < 0.05 or p < 0.01). Univariate Kaplan-Meier analysis showed that increased expression of CD146 (p = 0.056), higher average microvessel counts (p < 0.05), and lymph vessel counts (p < 0.05) were associated with decreased overall survival. Multivariate Cox regression analysis showed that average microvessel and lymph vessel counts (ps < 0.05) were independent prognostic predictors in gallbladder adenocarcinoma. Our study suggested that the elevated expression of CD146, angiogenesis, and lymphangiogenesis might be closely related to progression, invasion, metastasis, and prognosis of gallbladder adenocarcinoma.

Lymphangiogenesis is a predictor of nodal metastasis in extramammary Paget's disease

AIMS

The depth of dermal invasion, lymphatic invasion and tumour formation are thought to be predictors of nodal metastasis in extramammary Paget's disease (EPD). This study investigated the relationship between lymphangiogenesis and nodal metastasis in EPD.

METHODS AND RESULTS

Fifty cases (12 females and 38 males) with primary EPD of the external genitalia whounderwent surgical resection were studied. In 23 cases, inguinal lymph node dissection was performed, and nodal metastasis was found in eight cases. Lymphatic invasion and lymphangiogenesis were evaluated by D2-40 immunostain. Lymphangiogenesis was observed in 25 cases (50%). There were significant differences in the presence or absence of dermal invasion, depth of invasion, lymphatic invasion and nodal metastasis between the lymphangiogenesis group and non-lymphangiogenesis group.

CONCLUSION

Dermal invasion and depth of dermal invasion are predictors for nodal metastasis in EPD. However, in the current study, we demonstrate that lymphangiogenesis is also a predictor of nodal metastasis in EPD.

Long-term survival of a patient with common bile duct cancer after Virchow's node recurrence: Report of a case

A 62-year-old male patient with common bile duct (CBD) cancer underwent pancreaticoduodenectomy with lymphadenectomy in 2002. Histological examinations revealed moderately differentiated tubular adenocarcinoma with lymph node metastasis around the pancreas head and hepatoduodenal ligament. No adjuvant chemotherapy was performed, due to the risk of side effects. Two years after the first operation, new lesions developed at the left supraclavicular area. These lesions were considered to be Virchow's node metastasis of the original CBD cancer. However, we could not detect any other metastatic lesions in the intraabdominal lymph nodes around the aorta. We resected the lesion. Histological examinations showed a similar histological appearance of this lesion to that of the CBD cancer resected in 2002. At present, the patient has survived for more than 80 months after receiving the second surgery. In selected cases, surgery might be considered even for a Virchow's node metastasis of CBD cancers if there are no other recurrent lesions.

Nerve growth factor-beta expression is associated with lymph node metastasis and nerve infiltration in human hilar cholangiocarcinoma

BACKGROUND

Angiogenesis and lymphangiogenesis are important processes in the progression of malignant tumors. Previous studies have shown that nerve growth factor-beta (NGF-beta) can promote the initiation and progression of many tumors. In addition, vascular endothelial growth factor-C (VEGF-C) has become recognized as the most important lymphangiogenic factor. In the present study, the expression of NGF-beta in human hilar cholangiocarcinoma and its relationship with lymphangiogenesis, lymph node metastasis, nerve infiltration, and VEGF-C expression was investigated.

METHODS

Nerve growth factor-beta and VEGF-C expression were investigated by immunohistochemistry in samples from 28 cases of hilar cholangiocarcinoma. The lymphatic vessel density (LVD) in the tumor tissue that indicated lymphangiogenesis were calculated by immunostaining with the lymphendothelial-specific antibody D2-40. The relationship between NGF-beta expression and VEGF-C expression, lymphangiogenesis, lymph node metastasis, and nerve infiltration was evaluated.

RESULTS

The overexpression of NGF-beta and VEGF-C occurred in 57.1% (16/28) and 46.4% (13/28) of tumor samples, respectively. Nerve growth factor-beta overexpression was highly correlated with VEGF-C overexpression (P = 0.005), LVD (P < 0.001), lymph node metastasis (P = 0.021), nerve infiltration (P = 0.019), and tumor stage (P = 0.040). Furthermore, VEGF-C overexpression was highly correlated with LVD (P < 0.001) and lymph node metastasis (P < 0.001). However, there was no statistic significance in the relation between NGF-beta expression and sex (P = 0.185), age (P = 0.387), maximal tumor size (P = 0.736), Bismuth classification (P = 0.627) as well as histological grade (P = 0.203).

CONCLUSIONS

Nerve growth factor-beta might promote lymph node metastasis and nerve infiltration in human hilar cholangiocarcinoma.

Tumor-associated angiogenesis and lymphangiogenesis correlate with progression of intrahepatic cholangiocarcinoma

OBJECTIVES

Little is known about the function of tumor-associated neovascularization in the progression of intrahepatic cholangiocarcinoma (IHC). This study was conducted to evaluate the influence of tumor-associated angiogenesis and lymphangiogenesis on progression of IHC.

METHODS

We analyzed tissue specimens of IHC (N=114) by immunohistochemistry using the endothelial-specific antibody CD31 and the lymphendothelial-specific antibody D2-40 and subsequently quantified microvessel density (MVD) and lymphatic microvessel density (LVD). To analyze the influence of tumor-associated angiogenesis and lymphangiogenesis on tumor progression, tumors were allocated according to mean MVD and LVD, respectively, into groups of "high" and "low" MVD and LVD, respectively, and various clinicopathological characteristics as well as recurrence and survival data were analyzed.

RESULTS

IHC revealed an induction of tumor-associated angiogenesis and lymphangiogenesis. Tumors of "high" MVD displayed more frequently advanced primary tumor stages and multiple tumor nodes. Furthermore, patients with tumors of "high" MVD had an inferior curative resection rate and suffered more frequently from recurrence. A "high" LVD was correlated with increased nodal spread, and patients with "high" LVD tumors more frequently developed recurrence. In the univariate analysis, MVD and LVD revealed significant influence on survival, and MVD was identified as an independent prognostic factor for survival in the multivariate analysis. The 5-year survival of patients with "low" MVD tumors was 42.1%, compared with 2.2% in patients with "high" MVD tumors (P<0.001).

CONCLUSIONS

This study suggests a critical function of tumor-associated angiogenesis and lymphangiogenesis for progression of IHC. Therefore, antiangiogenic and antilymphangiogenic approaches may have therapeutic potency in this tumor entity.

Tumor-associated lymphangiogenesis correlates with prognosis after resection of human hepatocellular carcinoma

BACKGROUND

Experimental results from animal models as well as studies of human cancers indicate a critical role for tumor-associated lymphangiogenesis in tumor progression. However, its significance in hepatocellular carcinoma (HCC) is not well established.

METHODS

We analyzed tissue specimens from healthy liver (n = 36), cirrhotic liver (n = 24), and HCC (n = 60) by immunohistochemistry, using antibody D2-40 specific for lymphendothelia. We subsequently quantified lymphatic microvessel density (LVD). The LVD was correlated with clinicopathological characteristics of the tumors as well as survival and disease-free survival of the patients.

RESULTS

In contrast to healthy as well as cirrhotic liver, lymphangiogenesis was induced in HCC. Lymphatic vessels were detected in the intratumoral septa as well as within the bulk of tumor cells. Tumors with high LVD (24 of 60) had developed significantly more frequently in cirrhotic livers (P = 0.001) and were more frequently restricted to one liver lobe (P = 0.04). Univariate analysis revealed high LVD as a marker for reduced survival and disease-free survival disadvantage (median >60 vs. 21 months, P = 0.018, and 19 vs. 8 months, P = 0.047, respectively). In multivariate analysis, LVD showed a trend toward association with reduced survival (P = 0.059) and represented an independent prognostic factor for disease-free survival (P = 0.017).

CONCLUSIONS

Tumor-associated lymphangiogenesis is involved in neovascularization of hepatocellular carcinoma. Quantitative analysis of LVD demonstrated a significant influence of lymphangiogenesis on survival and established LVD as an independent predictor of disease-free survival. Quantification of LVD may be helpful in identifying patients with a high risk of tumor recurrence.

Microvessel density correlates with lymph node metastases and prognosis in hilar cholangiocarcinoma

BACKGROUND

Neovascularization was shown to be critically involved in the progression of multiple cancers, and treatment approaches targeting tumor-associated neovascularization provide convincing results in recent years in some tumor entities. However, little is known about the tumor-associated neovascularization in hilar cholangiocarcinoma. The present study was conducted to analyze tumor-associated neovascularization in hilar cholangiocarcinoma and to determine its influence on tumor growth, metastasis, recurrence, and prognosis.

METHODS

We analyzed tissue specimens of hilar cholangiocarcinoma (n = 60) by immunohistochemistry using the endothelial-specific antibody CD31 and subsequently quantified the microvessel density (MVD). The MVD was correlated with clinicopathological characteristics and recurrence pattern of the tumors as well as survival of patients.

RESULTS

Hilar cholangiocarcinoma revealed a high degree of vascularization, with a calculated mean MVD of 28.1 +/- 14.5 vessels. Tumors with a high MVD had a significant higher incidence of lymph node involvement (P = 0.009) and local recurrence (P < 0.001). Furthermore, a high MVD was identified to be a significant overall survival disadvantage (3-year, 28% vs. 93%; 5-year, 8% vs. 78%; P < 0.001) as well as disease-free survival disadvantage (3-year, 7% vs. 88%, 5-year, 7% vs. 72%; P < 0.001), with MVD representing an independent prognostic factor for survival.

CONCLUSIONS

Neovascularization is associated with nodal spread as well as local recurrence and serves as an independent prognostic factor for survival after curative resection of hilar cholangiocarcinoma. Therefore, tumor-associated neovascularization seems to be critically involved in the progression of this tumor entity. In addition, neovascularization may represent a potential target in he development of new therapeutic approaches in hilar cholangiocarcinoma.

Atu027, a liposomal small interfering RNA formulation targeting protein kinase N3, inhibits cancer progression

We have previously described a small interfering RNA (siRNA) delivery system (AtuPLEX) for RNA interference (RNAi) in the vasculature of mice. Here we report preclinical data for Atu027, a siRNA-lipoplex directed against protein kinase N3 (PKN3), currently under development for the treatment of advanced solid cancer. In vitro studies revealed that Atu027-mediated inhibition of PKN3 function in primary endothelial cells impaired tube formation on extracellular matrix and cell migration, but is not essential for proliferation. Systemic administration of Atu027 by repeated bolus injections or infusions in mice, rats, and nonhuman primates results in specific, RNAi-mediated silencing of PKN3 expression. We show the efficacy of Atu027 in orthotopic mouse models for prostate and pancreatic cancers with significant inhibition of tumor growth and lymph node metastasis formation. The tumor vasculature of Atu027-treated animals showed a specific reduction in lymph vessel density but no significant changes in microvascular density.

Assessment of hepatic VX2 tumors with combined percutaneous transhepatic lymphosonography and contrast-enhanced ultrasonographic imaging

AIM: To evaluate the feasibility and efficacy of percutaneous transhepatic lymphosonography (PTL) as a novel method for the detection of tumor lymphangiogenesis in hepatic VX₂ of rabbits and to evaluate combined PTL and routine contrast-enhanced ultrasonographic imaging for the diagnosis of liver cancer.

METHODS: Ten rabbits with VX₂ tumor were included in this study. SonoVue (0.1 mL/kg) was injected into each rabbit via an ear vein for contrast-enhanced ultrasonographic imaging, and 0.5 mL SonoVue was injected into the normal liver parenchyma near the VX₂ tumor for PTL. Images and/or movie clips were stored for further analysis.

RESULTS: Ultrasonographic imaging showed VX₂ tumors ranging 5-19 mm in the liver of rabbits. The VX₂ tumor was hyperechoic and hypoechoic to liver parenchyma at the early and later phase, respectively. The hepatic lymph vessels were visualized immediately after injection of contrast medium and continuously visualized with SonoVue^® during PTL. The boundaries of VX₂ tumors were hyperechoic to liver parenchyma and the tumors. There was a significant difference in the values for the boundaries of VX₂ tumors after injection compared with the liver normal parenchyma and the tumor parenchyma during PTL.

CONCLUSION: PTL is a novel method for the detection of tumor lymphangiogenesis in hepatic VX₂ of rabbits. Combined PTL and contrast-enhanced ultrasonographic imaging can improve the diagnosis of liver cancer.