Endoglin (CD105) expression in squamous cell carcinoma of the oral cavity

Endoglin in head and neck neoplasms

Tumors of the head and neck region form a heterogeneous group of pathologies, including various benign lesions and malignant neoplasms. Endoglin, also known as CD105, is an accessory receptor for transforming growth factor beta (TGF-β), that regulates angiogenesis, both under physiological and pathological conditions. It is highly expressed in proliferating endothelial cells. Therefore, it is considered as a marker of tumor-related angiogenesis. In this review we discuss the role of endoglin as a possible marker of carcinogenesis, as well as a potential target for antibody-based therapies in the neoplasms of the head and neck region.

Characterization of the Expression of Angiogenic Factors in Cutaneous Squamous Cell Carcinoma of Domestic Cats

Cutaneous squamous cell carcinoma (CSCC) is a common malignant skin cancer with a significant impact on health, and it is important to determine the degree of reliance of CSCC on angiogenesis for growth and metastasis. Major regulators of angiogenesis are the vascular endothelial growth factor (VEGF) family and their associated receptors. Alternative pre-mRNA splicing produces multiple isoforms of VEGF-A and PLGF with distinct biological properties. Several studies highlight the function of VEGF-A in CSCC, but there are no studies of the different isoforms of VEGF-A and PLGF for this neoplasm. We characterized the expression of three isoforms of VEGF-A, two isoforms of PLGF, and their receptors in cat CSCC biopsies compared to normal haired skin (NHS). Although our results revealed no significant changes in transcript levels of panVEGF-A or their isoforms, the mRNA levels of PLGF I and the receptors Flt-1 and KDR were downregulated in CSCC compared to NHS. Differences were observed in ligand:receptor mRNA expression ratio, with the expression of VEGF-A relative to its receptor KDR higher in CSCC, which is consistent with our hypothesis and prior human SCC studies. Immunolocalization in tissue showed increased expression of all measured factors and receptors in tumor cells compared to NHS and surrounding vasculature. We conclude that the factors measured may play a pivotal role in CSCC growth, although further studies are needed to clarify the role of angiogenic factors in feline CSCC.

Intratumoral lymphatic vascular density is an independent factor for disease-free and overall survival in advanced stage oral squamous cell carcinoma

OBJECTIVE

The presence of lymphatic and blood vessels in oral squamous cell carcinoma (OSCC) should play a key role in progression and dissemination. This study aimed to evaluate the correlation between the lymphatic and blood vessel densities with prognostic outcomes in advanced stage OSCC.

STUDY DESIGN

Immunohistochemical reactions for D-240, CD34, and CD105 were performed in 88 advanced stage OSCC cases located at the oral tongue and the floor of the mouth. The lymphatic vascular density (LVD), blood vascular density (BVD), and neoformed vascular density (NVD) were assessed by counting positive reactions in 4 hotspot areas, both intratumoral (IT) and peritumoral (PT), at high magnification (× 40).

RESULTS

High IT LVD was associated with extracapsular spread of lymph node metastasis (P = .03). Recurrence rates were correlated with IT LVD (P < .0001), IT BVD (P = .036), and IT NVD (P = .047), and overall survival was associated with high IT LVD (P = .0016) and IT NVD (P = .009). Yet, IT LVD was an independent factor for disease-free survival and for overall survival based on the Cox proportional hazards model.

CONCLUSIONS

Our results suggest that high IT LVD has a strong impact on survival outcomes in advanced stage OSCC.

Development and validation of a multivariable prediction model for the identification of occult lymph node metastasis in oral squamous cell carcinoma

BACKGROUND

There have been few recent advances in the identification of occult lymph node metastases (OLNM) in oral squamous cell carcinoma (OSCC). This study aimed to develop, compare, and validate several machine learning models to predict OLNM in clinically N0 (cN0) OSCC.

METHODS

The biomarkers CD31 and PROX1 were combined with relevant histological parameters and evaluated on a training cohort (n = 56) using four different state-of-the-art machine learning models. Next, the optimized models were tested on an external validation cohort (n = 112) of early-stage (T1-2 N0) OSCC.

RESULTS

The random forest (RF) model gave the best overall performance (area under the curve = 0.89 [95% CI = 0.8, 0.98]) and accuracy (0.88 [95% CI = 0.8, 0.93]) while maintaining a negative predictive value >95%.

CONCLUSIONS

We provide a new clinical decision algorithm incorporating risk stratification by an RF model that could significantly improve the management of patients with early-stage OSCC.

Prognostic value of blood and lymphatic vessel markers in tongue cancer: A systematic review

Tongue squamous cell carcinoma (TSCC) has a poor prognosis due to its early metastasis through blood and lymphatic vessels. We undertook a systematic review to investigate the prognostic significance of blood microvessel density (MVD) and lymphatic vessel density (LVD) in TSCC patients. We carried out a systematic search in Ovid Medline, Scopus, and Cochrane libraries. All studies that evaluated the prognostic significance of MVD/LVD markers in TSCC were systematically retrieved. Our results showed that MVD/LVD markers, CD31, CD34, CD105, factor VIII, lymphatic vessel endothelial hyaluronan receptor‐1, and D2‐40 were evaluated in TSCC patients until 28 June 2018. Six out of 13 studies reported markers that were associated with poor prognosis in TSCC. Two out of three studies suggested that a high number of D2‐40⁺ vessels predicated low overall survival (OS); the third study reported that the ratio of D2‐40⁺ over factor VIII⁺ vessels is associated with low OS. Most of the other markers had controversial results for prognostication. We found higher expression of MVD/LVD markers were commonly, but not always, associated with shorter survival in TSCC patients. It is therefore not currently possible to recommend implementation of these markers as reliable prognosticators in clinical practice. More studies (especially for D2‐40) with larger patient cohorts are needed.

18F-FDG-PET Can Predict Microvessel Density in Head and Neck Squamous Cell Carcinoma

Aim: Positron emission tomography (PET) with ¹⁸F-fluordeoxyglucose (¹⁸F-FDG) plays an essential role in the staging and tumor monitoring of head and neck squamous cell carcinoma (HNSCC). Microvessel density (MVD) is one of the clinically important histopathological features in HNSCC. The purpose of this study was to analyze possible associations between ¹⁸F-FDG-PET findings and MVD parameters in HNSCC. Materials and Methods: Overall, 22 patients with a mean age of 55.2 ± 11.0 and with different HNSCC were acquired. In all cases, whole-body ¹⁸F-FDG-PET was performed. For each tumor, the maximum and mean standardized uptake values (SUV_max; SUV_mean) were determined. The MVD, including stained vessel area and total number of vessels, was estimated on CD105 stained specimens. All specimens were digitalized and analyzed by using ImageJ software 1.48v. Spearman's correlation coefficient (r) was used to analyze associations between investigated parameters. p-values of <0.05 were taken to indicate statistical significance. Results: SUV_max correlated with vessel area (r = 0.532, p = 0.011) and vessel count (r = 0.434, p = 0.043). Receiver operating characteristic analysis identified a threshold SUV_max of 15 to predict tumors with high MVD with a sensitivity of 72.7% and specificity of 81.8%, with an area under the curve of 82.6%. Conclusion: ⁸F-FDG-PET parameters correlate statistically significantly with MVD in HNSCC. SUV_max may be used for discrimination of tumors with high tumor-related MVD.

Prediction of Occult Lymph Node Metastasis in Head and Neck Cancer with CD31 Vessel Quantification

Objective

The management of occult lymph node metastasis (LNM) in head and neck squamous cell carcinoma has been a matter of controversy for decades. The vascular density within the tumor microenvironment, as an indicator of ongoing angiogenesis, could constitute an attractive predictor of LNM. The use of the panvascular endothelial antibody CD31 as a marker of occult LNM has never been reported. The aim of this study was to assess the predictive value of CD31 microvascular density for the detection of occult LNM in squamous cell carcinoma of the oral cavity and oropharynx.

Study Design

Case series with chart review.

Setting

Tertiary university hospital.

Subjects and Methods

Intra- and peritumoral microvascular density values were determined in 56 cases of squamous cell carcinoma of the oral cavity (n = 50) and oropharynx (n = 6) with clinically negative necks using the CD31 marker. Statistical associations of CD31 microvascular densities with clinicopathologic data were then established.

Results

Peritumoral CD31 microvascular density was significantly associated with occult LNM in multivariate analysis ( P < .01). Recursive partitioning analysis for this parameter found a cutoff of 19.33, which identified occult LNM with a sensitivity of 91%, a specificity of 65%, a positive predictive value of 40%, a negative predictive value of 97%, and an overall diagnostic accuracy of 71%.

Conclusion

Peritumoral CD31 microvascular density in primary squamous cell carcinoma of the oral cavity and oropharynx allows accurate prediction of occult LNM.

Microvessel density in head and neck squamous cell carcinoma

Purpose

Microvessel density (MVD) corresponds to the intensity of neo-angiogenesis. MVD assessments are based on the expression levels of the vascular endothelium markers such as, e.g., CD34 or CD105. The goal of this study was to assess MVD among patients with head and neck squamous cell carcinoma (HNSCC), and to evaluate the predictive value of MVD in head and neck cancers.

Methods

The study included 49 patients treated for HNSCC and 11 patients with dysplasia of the upper respiratory tract epithelium. Control tissues consisted of 12 normal mucous membranes of the throat. Expression levels of MVD markers were assessed by immunohistochemistry (IHC) using tissue microarrays (TMA). Clinicopathological factors and patients’ survival over the 5-year follow-up period were analyzed.

Results

The MVD/CD34 values were found to be significantly elevated in the HNSCCs compared to the non-malignant control tissues (p = 0.001) and to dysplastic tissues. (p = 0.02). Significantly higher MVD/CD105 values were also seen in the tumor compared to the control tissues (p = 0.001) or the dysplastic tissues (p = 0.001). Unexpectedly, significantly lower MVD/CD34 values were seen in the tumor tissues of patients with the T3–T4 tumors compared to those with T1–T2 tumors (p = 0.01).

Conclusions

HNSCCs have statistically higher MVD values compared to dysplasia of the upper respiratory tract epithelium. However, the MVD/CD34 values did not correlate with local invasiveness (the T feature) of HNSCCs. This counterintuitive observation suggests that assessments of MVD as performed on TMA by IHC using anti-CD34 or anti-CD105 antibodies considered to be specific for endothelial cell markers might underestimate the extent of the tumor vascularity in HNSCC.

Biomarkers and Immunotherapeutic Targets in Glioblastoma

Glioblastoma (GBM) is an aggressive central nervous system cancer with poor prognosis despite maximal therapy. The recent advent of immunotherapy holds great promise for improving GBM survival and has already made great strides toward changing management strategies. A diverse set of biomarkers have been implicated as immunotherapeutic targets and prognostic indicators in other cancers. Some of the more extensively studied examples include cytokines (IL-4, IL-13, and TGF-β), checkpoint molecules (PD-1, CTLA-4, TIM-3, LAG-3, CD137, GITR, OX40), and growth/angiogenesis proteins (endoglin and EGFR). Emerging theories involving the tumor mutational landscape and microbiome have also been explored in relation to cancer treatment. Although identification of novel biomarkers may improve and help direct treatment of patients with GBM, the next step is to explore the role of biomarkers in precision medicine and selection of specific immunotherapeutic drugs in an individualized manner.

Immunohistochemical Expression of CD105 and TGF-β1 in Oral Squamous Cell Carcinoma and Adjacent Apparently Normal Oral Mucosa and its Correlation With Clinicopathologic Features

Angiogenesis in oral squamous cell carcinomas (OSCC) is essential for its growth, invasion, and metastasis. This entails a shift in the balance between proangiogenic and antiangiogenic factors. CD105 and TGF-β1 are 2 such proangiogenic factors wherein CD105 exerts its angiogenic effect by binding to and modulating the TGF-β1 pathway. A total of 50 resected specimens of OSCC were considered. One tissue specimen was taken from tumor proper and another specimen from adjacent apparently normal mucosa (AANM). Both tissues were immunohistochemically stained using CD105 and TGF-β1 antibodies. The expression of each antibody was individually assessed and then compared. Pearson χ test was used for statistical comparison of expression. CD105 was significantly expressed in OSCC as compared with AANM and also correlated with increasing TNM stage. The mean microvessel density was higher in OSCC. TGF-β1 was significantly expressed in epithelium of OSCC as compared with AANM. On comparing expression of TGF-β1 and CD105, 79.54% of endothelial cells expressed positivity for both molecules. Both CD105 and TGF-β1 were increased in OSCC, although based on our results CD105 alone can be used as a prognostic marker. On the basis of immunohistochemical expression of CD105 and TGF-β1 in endothelial cells, our results demonstrate that CD105 acts as one of the receptors of TGF-β1 on endothelial cells and induces the angiogenic pathway in OSCC.

Expression of Endoglin (CD-105) and Microvessel Density in Oral Dysplasia and Squamous Cell Carcinoma

OBJECTIVE

To assess the expression of Endoglin (CD-105) and Microvessel Density in clinically normal oral mucosa of non-tobacco and tobacco habituated patients & also histopathologically confirmed cases of oral squamous cell carcinoma (OSCC) patients.

MATERIALS AND METHODS

Twenty cases of clinically normal oral mucosa with tobacco habituation in the form of chewing or smoking, 20 histopathologically confirmed cases of OSCC and twelve normal healthy oral mucosal cases without tobacco habituation in any form, served as control group, were immunohistochemically analysed for expression of Endoglin (CD-105). Chi-square test is used to determine statistical analysis and significance.

RESULT & CONCLUSION

The finding of 65% of Endoglin CD - 105 positivity and microvessel density (MVD) in the mucosal specimens of tobacco users may be attributed as neoangiogenesis or angiogenic squamous dysplasia like phenomenon occurring as important pathological biomarker preceding oral cancer development, and may therefore be useful as a predictive marker of malignancy.

Preparation, antiangiogenic and antitumoral activities of the chemically sulfated glucan from Phellinus ribis

Two sulfated derivatives (PRP-S1 and PRP-S2) of a β-glucan from Phellinus ribis with different degrees of substitution were obtained by chlorosulfonic acid method. The derivatives could block formation of new vessels in zebrafish and inhibit the proliferation of human umbilical vein endothelial cells (HUVECs). The two sulfated derivatives had remarkably high antitumor activities in vivo (in BALB/c mice inoculated with H22 hepatocellular carcinoma) as well as in vitro (against human ovary cancer SKOV-3 cells), without producing any overt signs of general toxicity. The results of immunohistochemistry assay indicated that the derivatives significantly reduced the average number of microvessel density (MVD) and inhibited the expression of vascular endothelial growth factor (VEGF) in tumor. Thus, these derivatives exhibit pronounced antiangiogenic and antitumoral properties. Except for cytotoxic effects on tumor cells, it is reasonable to expect that the antitumoral effects of PRP-S1 and PRP-S2 are mediated via their antiangiogenic properties.

Lymphangiogenesis and podoplanin expression in oral squamous cell carcinoma and the associated lymph nodes

The objective of this study was to evaluate lymphangiogenesis in oral squamous cell carcinoma and in the associated lymph nodes and podoplanin expression in neoplastic cells at the invasive front. In addition, the association of the above parameters with lymph node metastasis was also investigated. We used immunohistochemistry to examine primary tumors and lymph nodes, regardless of metastasis. Lymphatic vessel density (LVD) and microvessel density (MVD) were assessed by antibodies D2-40 and CD105, respectively, in intratumoral and peritumoral areas and in lymph node regions. Vascular endothelial growth factor-C and vascular endothelial growth factor receptor-3 expression was evaluated in tumor cells and D2-40 (podoplanin) expression in parenchymal cells found at the invasive front. The majority of cases with nodal involvement presented a high peritumoral LVD. In addition, a strong association of LVD with size and site of primary tumors could also be identified. MVD was statistically associated with metastasis, and a significant association between the lymphangiogenic factors and the density of vessels in the intratumoral region was also seen. The well-differentiated tumors did not express podoplanin. LVD and MVD were higher in metastatic lymph nodes than in nonmetastatic lymph nodes. The enhanced vascular network in metastatic lymph nodes reinforces the previous reports of lymphangiogenesis occurrence in lymph nodes. Moreover, the expression of podoplanin by more undifferentiated tumor cells suggests that this protein could be an indicator of tumor aggressiveness.

The role of angiogenin in pT1-T2 tongue carcinoma neo-angiogenesis and cell proliferation: an exploratory study

BACKGROUND

Angiogenin (ANG) is a member of the ribonuclease superfamily and of medical interest largely because it supports the growth of primary and metastatic malignancies. This study is the first to investigate the potential role of ANG in tongue carcinoma neo-angiogenesis and cancer cell proliferation.

METHODS

Angiogenin expression (in carcinoma cells and endothelial intratumor vessel cells), CD105-assessed micro-vessel density (MVD), and MIB-1 expression were correlated with prognostic parameters in 28 primarily consecutively operated pT1-T2 tongue carcinomas (squamous cell carcinoma [SCC]). Whenever feasible, a computer-based image analysis system was used for the immunohistochemical reaction analysis.

RESULTS

No significant correlations emerged between ANG expression in the tongue carcinoma cells or endothelial intratumor vessel cells and tongue SCC recurrence rate or disease-free survival (DFS). ANG expression was also unrelated to CD105-assessed MVD or MIB-1 expression. Conversely, CD105-assessed MVD correlated directly with recurrence rate (P = 0.02) and DFS was significantly shorter in cases with CD105-assessed MVD >167 micro-vessels/mm(2) than in those with CD105-assessed MVD ≤167 micro-vessels/mm(2) (P = 0.042).

CONCLUSIONS

Our results support the hypothesis that CD105-assessed MVD would be a valuable parameter for predicting which patients with tongue SCC are at greatest risk of disease recurrence. Despite our study results, the role of ANG in tongue carcinoma warrants further investigation in larger series.

Recurrent copy number gains of ACVR1 and corresponding transcript overexpression are associated with survival in head and neck squamous cell carcinomas

AIMS

This study aimed to evaluate the copy number alteration on 2q24, its association with ACVR1 transcript expression and the prognostic value of these data in head and neck squamous cell carcinomas.

METHODS AND RESULTS

Twenty-eight samples of squamous cell carcinoma were evaluated by fluorescence in situ hybridization (FISH) using the probes RP11-546J1 (2q24) and RP11-21P18 (internal control). Significant gains at 2q24 were detected in most cases at frequencies varying from 3 to 35%. ACVR1 gains and amplifications were associated with longer overall survival (P = 0.022). ACVR1 mRNA expression analysis in 78 cases revealed overexpression in 44% (34 of 78) of these tumours, suggesting that gene copy number alterations could be involved in gene overexpression. In laryngeal carcinomas, overexpression of ACVR1 mRNA levels was associated with longer overall survival (P = 0.013). Multivariate analysis revealed that ACVR1 is an independent prognostic marker in laryngeal carcinomas (P = 0.012, hazard ratio = 0.165, 95% confidence interval =0.041-0.668).

CONCLUSIONS

These findings suggest that copy number alterations at 2q24 can be involved in ACVR1 overexpression, which is associated with longer overall survival in laryngeal carcinomas. To our knowledge, this is the first report indicating the relevance of ACVR1 expression in head and neck cancers.

CD105 is a marker of tumour vasculature and a potential target for the treatment of head and neck squamous cell carcinoma

BACKGROUND

The importance of angiogenesis in solid tumour growth is well recognised. Tumour angiogenesis is considered the result of an imbalance between pro- and anti-angiogenic factors produced by both the malignancy and normal cells. Endoglin (CD105) is a proliferation-associated, hypoxia-inducible glycoprotein that seems to be clinically superior to other pan-endothelial markers in the selective evaluation of tumour angiogenesis. Several studies have revealed CD105 up-regulation in a wide range of tumour endothelia. Since 2002, endothelial CD105 expression has also been retrospectively investigated in patients with head and neck squamous cell carcinoma (HNSCC).

METHODS

An exhaustive literature review was performed to investigate available evidence on CD105 expression and its biological role and therapeutic potential in HNSCC.

RESULTS

The available evidence supports the hypothesis that CD105 expression in HNSCC may be a valuable parameter for pinpointing patients at greater risk of recurrent malignancy and with a worse prognosis. A high CD105 expression in HNSCC was associated with metastatic lymph nodes in most of the studies.

CONCLUSIONS

Prospective studies are mandatory to confirm that CD105 expression is a significant prognostic hallmark in HNSCC. The results of prospective studies could be relevant for the adoption of stricter follow-up protocols and/or alternative therapeutic regimens for patients with a high CD105 expression in HNSCC. Great interest is currently being focused on vascular targeting for therapeutic purposes. Preclinical studies on appropriate animal models resembling HNSCC to investigate the effects of inhibiting CD105 may show the efficacy of combined treatment strategies associating angiogenic-targeted with conventional therapies for HNSCC.

Poor prognostic clinicopathologic features correlate with VEGF expression but not with PTEN expression in squamous cell carcinoma of the larynx

Background

The aim of this study was to assess the relationship between expression of vascular endothelial growth factor (VEGF) and phosphatase and tensin homolog deleted in chromosome ten (PTEN), angiogenesis and clinicopathological parameters of squamous cell carcinoma of the larynx.

Methods

We examined immunohistochemical expression of VEGF and PTEN and CD34 for microvessel density (MVD) in sections of formalin-fixed, paraffin embedded tissue blocks of 140 patients with squamous cell carcinoma of the larynx. The intensity of VEGF and PTEN staining and the proportion of cells staining were scored.

Results

The tumor grade was not significantly related to PTEN expression, but it was to VEGF expression (p = 0.400; p = 0.015, respectively). While there was no significant relationship between PTEN expression and tumor size and cartilage invasion (p = 0.311, p = 0.128), there was a significant relationship between the severity of VEGF expression and tumor size (p = 0.006) and lymph node metastasis (p = 0.048) but not cartilage invasion (p = 0.129). MVD was significantly higher in high-grade tumors (p = 0.003) but had no significant relationship between MVD, lymph node metastasis, and cartilage invasion (p = 0.815, p = 0.204). There was also no significant relationship between PTEN and VEGF expression (p = 0.161) and between PTEN and VEGF expression and the MVD (p = 0.120 and p = 0.175, respectively).

Conclusions

Increased VEGF expression may play an important role in the outcome of squamous cell carcinoma of the larynx. PTEN expression was not related to VEGF expression and clinicopathological features of squamous cell carcinoma of the larynx.

Targeting cancer vasculature via endoglin/CD105: a novel antibody-based diagnostic and therapeutic strategy in solid tumours

Endoglin/CD105 is well acknowledged as being the most reliable marker of proliferation of endothelial cells, and it is overexpressed on tumour neovasculature. Our current knowledge of its structure, physiological role, and tissue distribution suggests that targeting of endoglin/CD105 is a novel and powerful diagnostic and therapeutic strategy in human malignancies, through the imaging of tumour-associated angiogenesis and the inhibition of endothelial cell functions related to tumour angiogenesis. Among biotherapeutic agents, monoclonal antibodies have shown a major impact on the clinical course of human malignancies of different histotypes. Along this line, the potential efficacy of anti-endoglin/CD105 antibodies and their derivatives for clinical purposes in cancer is supported by a large body of available pre-clinical in vitro and in vivo data. In this review, the main findings supporting the translation of antibody-based endoglin/CD105 targeting from pre-clinical studies to clinical applications in human cancer are summarized and discussed.

Prognostic Relevance of CD105-Assessed Microvessel Density in Laryngeal Carcinoma

OBJECTIVE: To examine immunohistochemical expression of CD105 among patients with laryngeal cancer and investigate the prognostic significance of CD105-assessed microvessel density (MVD).

STUDY DESIGN: Cross-sectional study.

SETTING: University hospital.

SUBJECTS AND METHODS: The study comprised 80 patients with laryngeal squamous cell carcinoma who underwent complete excision. Clinicopathological data were collected retrospectively. Immunohistochemical analysis was performed with CD105 (endoglin) antibody. Positive-stained microvessels for CD105 were counted on hot spots of tumors at ×200 magnification.

RESULTS: Average CD105-assessed MVD in considered laryngeal squamous cell carcinomas (SCCs) was 12.9 (SD 3.84). High expression of CD105 correlated significantly with advanced T (tumor) classification ( P = 0.008), advanced TNM (tumor, node, metastasis) stage ( P = 0.001), tumor recurrence ( P = 0.001), and age ≥65 years ( P = 0.026). The multivariate logistic regression showed that a high CD105+ MVD (odds ratio [OR] 4.27; P = 0.019) and advanced TNM stage (OR 3.72; P = 0.047) were independent markers of tumor recurrence. High MVD, advanced clinical stage, the presence of lymph node metastasis at the time of diagnosis, and age <66 years were associated with worse disease-free survival. Cox regression analysis revealed that expression of CD105 ( P = 0.016) and advanced clinical stage ( P = 0.05) were the independent factors for disease-free survival.

CONCLUSION: The present results suggest that MVD evaluation with CD105 is a promising prognostic factor for the outcome of patients with laryngeal SCC. CD105-assessed MVD could help to identify patients with more aggressive disease and increased risk of developing malignancy recurrence after treatment.

[Prognostic significance of angiogenesis in surgically treated supraglottic squamous cell carcinomas of the larynx]

INTRODUCTION AND OBJECTIVES

It is now generally accepted that angiogenesis is crucial in tumour growth. However, controversy still exists regarding the prognostic significance of angiogenesis in head and neck carcinomas. The aim of this paper is to determine the prognostic significance of angiogenesis in a homogeneously treated group of supraglottic squamous cell carcinomas.

MATERIAL AND METHODS

108 patients surgically treated for squamous cell carcinoma of the supraglottic larynx were studied. Angiogenesis was estimated in the primary tumour and in the nodal metastases by determining microvessel density using the "hot spot" method. Anti-CD34 antibody was used to stain blood vessels.

RESULTS

The mean microvessel density in primary tumours was 72+/-34 vessels/mm(2) and 58.5+/-31.5 vessels/mm(2) in nodal metastases. No correlation was found between microvessel density in the primary tumours and the corresponding nodal metastasis (P=0.195). No significant differences in microvessel density were observed in relation to clinico-pathological parameters or survival (P=0.19).

CONCLUSIONS

Our results suggest that microvessel density is not a useful prognostic marker in surgically treated supraglottic squamous cell carcinomas.

Assessment of vascularity as an index of angiogenesis in periradicular granulomas. Comparison with oral carcinomas and normal tissue counterparts

AIM

To quantify vascularity in periradicular granulomas using different endothelial markers, and assess its value as an index of angiogenesis by comparing granulomas with healthy periodontal ligament (PDL). To use oral tumours, compared with adjacent normal mucosa, as positive controls.

METHODOLOGY

Paraffin-embedded sections were stained with antibodies to von Willebrand factor (vWF), a pan-endothelial marker, and CD105, a putative marker for angiogenic vessels. Vascularity was quantified by different methods reflecting vessel volume and density.

RESULTS

Irrespective of the marker or method used, vascularity values were similar in periradicular granuloma and PDL. Both tissues were highly vascularized, with levels similar to those found in oral squamous cell carcinoma. Vascularity was significantly higher in the latter than in normal mucosa. Fewer vessels were positive for CD105 than for vWF in the normal mucosa, whereas similar numbers were found in the other tissues examined.

CONCLUSIONS

A comparison of vascularity in oral tumours and normal oral mucosa provided evidence of angiogenesis in the former. Staining with CD105 added limited value to staining with vWF in these tissues. In contrast, a comparison of periradicular granuloma and PDL failed to demonstrate evidence of angiogenesis in the granuloma. As all vessels were similarly stained with vWF and CD105 in granuloma and PDL, a possible hypothesis is that all vessels are newly formed in these tissues. A more plausible alternative is that CD105 expression may reflect the metabolic activity or intrinsic characteristics of the tissues, rather than the presence of angiogenic vessels.

Transforming growth factor-beta binding receptor endoglin (CD105) expression in esophageal cancer and in adjacent nontumorous esophagus as prognostic predictor of recurrence

BACKGROUND

We hypothesized that the potent neovascularization marker endoglin (CD105), by differentially highlighting a subset of microvessels (MV) in esophageal cancer (EC), could provide better prognostic/therapeutic information than the panendothelial marker CD34, which also highlights MV.

METHODS

Endoglin messenger ribonucleic acid (mRNA) expression in normal, malignant, and adjacent nontumorous esophagus tissue was quantified by real-time reverse-transcription polymerase chain reaction (RT-PCR). Sections of formalin-fixed, paraffin-embedded tissues were analyzed immunohistochemically for CD105 and CD34. MV density was counted following a standard protocol. Circulating soluble endoglin levels were determined in patient and control sera, and compared with clinical outcome.

RESULTS

CD105 mRNA was upregulated by a median factor of 2.89 in ECs versus controls. In 28% of patients, CD105 mRNA was upregulated by a median factor of 2.65 in adjacent non-tumorous versus normal tissue. In tumor tissues, CD105 was stained negatively or positively only in a subset of MV. CD34 always showed positive extensive MV staining. In adjacent nontumorous esophagus, CD105 rarely showed diffuse MV staining, while CD34 stained blood-vessel endothelial cells in all non-neoplastic tissue. CD105 expression was high in residual highly dysplastic Barrett's-type mucosa associated with some adenocarcinomas. No statistically significant difference in endoglin serum levels appeared between patients and normal subjects. Correlation with clinicopathological data showed higher intra-tumor MV-CD105+ scores at more-advanced clinical stages. High-scoring MV-CD105+ patients had significantly shorter disease-free and overall survival; MV-CD34+ density was not survival related. Diffuse CD105 expression in adjacent nontumorous esophagus predicted poorer disease-free and overall survival.

CONCLUSIONS

Our findings could help identify EC patients who may benefit from targeted anti-angiogenic therapies.

Significance of neo-angiogenesis and immuno-surveillance cells in squamous cell carcinoma of the tongue

Background

Neo-angiogenesis is an essential process in physiological and pathological conditions. However, it is a complex process. Several studies demonstrated that intra-tumoural microvessel number is a significant predictor of metastasis and clinical outcome in many tumours, including oral malignancies. The immuno-surveillance cells, mast cells and eosinophils are implicated in the biological behaviour of tumours. Nevertheless, their function in tissues is uncertain. Mast cells are involved in homeostatic regulation of blood vessels as well as host defence. In some malignancies, high mast cell density has been found to correlate with favourable prognosis. However, others reported unfavourable associations. Tumour associated tissue eosinophilia is a well-known phenomena. It has been associated with good and poor prognosis. However, the role of eosinophils in tumours remains controversial. Therefore, this study was designed to investigate the prognostic value of microvessel, mast cell and eosinophil densities in the context of clinico-pathological parameters and survival in squamous cell carcinoma of the tongue.

Materials and Methods

Anti-CD105 and anti-tryptase monoclonal antibodies were utilized to highlight and count microvessels and mast cells respectively in 81 cases of tongue squamous cell carcinoma. Eosinophils were demonstrated using carbol chromotrope histochemical stain. The densities were counted per mm2 and correlated with patients’ outcome and other clinico-pathological parameters using non-parametric tests and student's t-test. Clinically, the cases were divided into 4 main groups depending on survival time, lymph-node or distant metastasis.

Results

The 5 year survival was significantly lower in patients with a low mast cell density than those with a high density (p=0.006, Kruskal-Wallis test). The survival group-A demonstrated significantly higher mast cell and microvessel numbers than group-D (p=0.007, student's t-test) respectively. Patients with well- differentiated squamous cell carcinoma had significantly higher numbers of mast cells when compared to patients with poorly differentiated squamous cell carcinoma (p<0.05, student's t-test). The lymph node involvement correlation between the survival group-A and survival group-D was also significant (p=0.001, Mann-Whitney U test).

Conclusion

Data from this study indicates that accumulating mast cells in tumours play a part in inhibiting tumour progression and is potentially angiogenic in tumours.

CD105-assessed micro-vessel density is associated with malignancy recurrence in laryngeal squamous cell carcinoma

AIMS

Angiogenesis is essential for malignancies growth. CD105 is a proliferation-associated protein abundantly expressed in angiogenic endothelial cells. The aim of this study has been to determine the expression of CD105 in laryngeal squamous cell carcinoma (SCC) and to investigate the role of CD105-assessed mean vascular density (MVD) in predicting patients' prognosis.

METHODS

The sections of 43 consecutive cases of laryngeal SCC were stained with mouse monoclonal antibody CD105. All the measures were performed by a computer-based image analysis system. The percentage of the fields occupied by CD105-assessed micro-vessels was determined.

RESULTS

The mean CD105-assessed MVD were 11% and 6% in laryngeal SCC with and without malignancy recurrence, respectively. Multivariate logistic regression stated that CD105-assessed MVD was significantly related to disease recurrence (p=0.030).

CONCLUSIONS

Our preliminary results suggest that CD105-assessed MVD may be a valuable parameter for predicting patients having an increased risk of developing laryngeal carcinoma loco-regional recurrence.

High expressions of CD105 and VEGF in early oral cancer predict potential cervical metastasis

BACKGROUND AND OBJECTIVES

Although elective neck dissection has become a popular treatment modality for early oral cancer among most head and neck surgeons, a large portion of patients revealed pathological N0 postoperatively. Our study is aimed to evaluate the expressions of the angiogenic factors, vascular endothelial growth factor (VEGF), and CD105 (endoglin) on the prediction of neck metastasis for clinical N0 patients in early oral cancer.

PATIENTS AND METHODS

Between July 1996 and July 2005, the preoperative biopsy specimens among 176 patients who underwent surgical treatment for early oral cancer were retrieved for the immunohistochemical study for VEGF and CD105.

RESULTS

High expressions of CD105 and VEGF significantly correlated with positive nodal metastasis, respectively (P<0.001). The expression of CD105 also significantly correlated with that of VEGF (P<0.001). Furthermore, the sensitivity and specificity for prediction of cervical metastasis by high expressions of CD105 versus VEGF were 81.8% and 97.7% versus 93.2% and 72%, respectively. Low expression of CD105 and VEGF also significantly correlated with higher survival rate, respectively (P<0.001).

CONCLUSIONS

Besides the image studies, the expressions of both CD105 and VEGF could be useful to guide the elective treatment for clinical N0 neck in early oral cancer.

Expression of NOS and HIF-1α in human colorectal carcinoma and implication in tumor angiogenesis

AIM: To study CD34, CD105, inducible nitric oxide synthase (iNOS), endogenous nitric oxide synthase (eNOS), and hypoxia-inducible factor 1 (HIF-1) α expression in human colorectal carcinomas.

METHODS: The tissue microarrays (TMAs) were made up of 80 cases of colorectal carcinoma and 80 cases of non-neoplasm colorectal mucosa. The expression of CD34, CD105, NOS and HIF-1α was detected by immunohistochemistry (S-P).

RESULTS: iNOS and HIF-1α expression in colorectal carcinoma was significantly higher than in non-neoplasm colorectal mucosa (χ² = 43.166, P < 0.01; χ² = 10.4278, P < 0.01); eNOS expression in colorectal carcinoma was significantly lower than in non-neoplasm colorectal mucosa (χ² = 11.354, P < 0.01). The expression of iNOS correlated with differentiation (χ² = 18.141, P < 0.01), invasive depth (χ² = 4.748, P < 0.01), and Micro vessel density (MVD) (t = 2.327, P < 0.05). The expression of HIF-1α was correlated with infiltrating depth (χ² = 4.397, P < 0.05), Duke’s staging (χ² = 4.255, P < 0.05), and MVD (t = 2.272, P < 0.05). No correlation was found in eNOS expression.

CONCLUSION: Over-expression of iNOS and HIF-1α in colorectal carcinoma is correlated with the biological character MVD.

High Expression of CD105 as a Prognostic Predictor of Early Tongue Cancer

OBJECTIVES

The purpose of this article is to investigate the expressions of vascular endothelial growth factor (VEGF) and endoglin (CD105) in the biopsy tissues of squamous cell carcinoma of the tongue in early tumor stages and their relationship with the clinicopathologic features.

STUDY DESIGN AND METHODS

The authors conducted retrospective clinical and biologic studies. Immunohistochemistry was used to study the expressions of VEGF and CD105 in the biopsy tissues taken from 94 patients with T1 and T2 tongue cancers. The expressions of VEGF and CD105 were analyzed and correlated to the clinicopathologic features of these patients.

RESULTS

High expressions of VEGF and CD105 significantly correlated with a relatively advanced tumor stage (P=.001 and P<.001), positive nodal status (P<.001 and P<.001), presence of tumor necrosis (P=.022 and P=.01), and greater tumor thickness (P<.001 and P<.001), respectively. In addition, high expression of CD105 correlated with the presence of perineural invasion (P=.003). However, the expression of VEGF and CD105 did not significantly correlate with age, gender, vascular invasion, or histologic grading. The cumulative 5-year disease-free survival rate significantly correlated with low expression of VEGF (P=.003), CD105 (P<.001), positive nodal status (P<.001), a relatively advanced tumor stage (P=.024), greater tumor thickness (P=.023), and presence of tumor necrosis (P=.003). Nonetheless, Cox's regression analysis revealed that only the expression of CD105 was an independent prognostic predictor for survival (P<.001).

CONCLUSIONS

Higher expression of either CD105 or VEGF in the tumor bed implicates a more aggressive potential for T1 and T2 tongue cancers, and the expression of CD105 is a useful predictive prognostic factor in early tongue cancer.

Endoglin expression is associated with poor oncologic outcome in oral and oropharyngeal carcinoma

CONCLUSIONS

The present preliminary results suggest that endoglin (CD105)-assessed micro-vessel density (MVD) in primary oral and oropharyngeal squamous cell carcinomas (SCCs) may identify patients at risk of disease recurrence or poor oncological outcome after treatment.

OBJECTIVES

MVD is an independent prognostic indicator in several human malignancies. Endoglin antibodies have shown a greater specificity for tumour vasculature in comparison with pan-endothelial markers. The present explorative study evaluated endoglin expression and its prognostic role in oral and oropharyngeal SCCs.

PATIENTS AND METHODS

The study considered 13 consecutive cases of oral and oropharyngeal SCC with lymph node metastases (pN+) and 13 consecutive pN0 cases. CD105-assessed MVD was calculated at 400x magnification.

RESULTS

The mean MVDs were 3.6 and 3.1 in pN+ and pN0 groups, respectively (p>0.05). The mean CD105-assessed MVDs were 4.7 in the group with locoregional recurrence and 2.9 in the group without locoregional recurrence or post-treatment diagnosis of distant metastasis (p=0.01). The mean CD105-assessed MVD in primary oral and oropharyngeal SCCs with poor oncological outcome (recurrence of disease or occurrence of distant metastasis) was 4.3. The mean MVD in primary oral and oropharyngeal SCCs with good outcome was 2.9. Statistical analysis showed a significant difference between CD105-assessed MVD in poor and good outcome groups (p=0.02).

The risk of developing metastatic disease in colorectal cancer is related to CD105-positive vessel count

BACKGROUND AND OBJECTIVES

Angiogenesis is a complex multistep process that involves extracellular matrix remodeling, migration and proliferation of endothelial cells, and morphogenesis of microvessels. CD105 (endoglin), a co-receptor of the TGF-beta superfamily, was proposed as a marker of neovascularization in solid malignancies. The aim of this study was to evaluate retrospectively the effect of CD105-assessed angiogenesis on the risk of developing metastatic disease in colorectal cancer (CRC).

METHODS

One hundred and twenty-five paraffin-embedded samples were analyzed by immunohistochemical methods using a CD105 monoclonal antibody. The median follow-up was 70.8 months. Survivals were calculated from actuarial estimates, and logistic regression predicted the risk of developing metastatic disease.

RESULTS

The CD105-vessel count was strongly correlated with the occurrence of metastatic disease. The median CD105-positive vessels in patients with and without metastatic disease were 24.7 and 13.2 vessels/mm(2), respectively (P < 0.001). For each one microvessel increase in the vessels count per 400x field, there was a 1.42-fold increase in the risk of metastatic disease (P < 0.001).

CONCLUSIONS

The assessment of tumor angiogenesis with anti-CD105 was not sufficient for its use as a surrogate end point for survival because of the amount of survival variability explained was only 8% in absence of metastatic disease. In contrast, multivariate logistic regression analysis revealed that CD105-vessels count can identify patients at high risk of metastatic disease.

Correlation between CD105 expression and postoperative recurrence and metastasis of hepatocellular carcinoma

Background

Angiogenesis is one of the mechanisms most critical to the postoperative recurrence and metastasis of hepatocellular carcinoma (HCC). Thus, finding the molecular markers associated with angiogenesis may help identify patients at increased risk for recurrence and metastasis of HCC. This study was designed to investigate whether CD105 or CD34 could serve as a valid prognostic marker in patients with HCC by determining if there is a correlation between CD105 or CD34 expression and postoperative recurrence or metastasis.

Methods

Immunohistochemical staining for the CD105, CD34 and vascular endothelial growth factor (VEGF) antibodies was performed in 113 HCC tissue specimens containing paracarcinomatous tissue and in 14 normal liver tissue specimens. The quantitation of microvessels identified by anti-CD105 and anti-CD34 monoclonal antibodies and the semiquantitation of VEGF expression identified by anti-VEGF monoclonal antibody were analyzed in conjunction with the clinicopathological characteristics of the HCC and any available follow-up information about the patients from whom the specimens were obtained.

Results

CD105 was not expressed in the vascular endothelial cells of any normal liver tissue or paracarcinomatous liver tissue but was expressed in the vascular endothelial cells of all HCC tissue. In contrast, CD34 was expressed in the vascular endothelial cells of normal liver tissue, paracarcinomatous tissue, and HCC tissue in the following proportions of specimens: 86.7%, 93.8%, and 100%, respectively. The microvascular densities (MVDs) of HCC determined by using an anti-CD105 mAb (CD105-MVD) and an anti-CD34 mAb (CD34-MVD), were 71.7 ± 8.3 (SD) and 106.3 ± 10.4 (SD), respectively. There was a significant correlation between CD105-MVD and CD34-MVD (r = 0.248, P = 0.021). Although CD34-MVD was significantly correlated with VEGF expression (r = 0.243, P = 0.024), CD105-MVD was more closely correlated (r = 0.300, P= 0.005). The correlation between microscopic venous invasion and CD105-MVD, but not CD34-MVD, was also statistically significant (r = 0.254, P = 0.018). Univariate analysis showed that CD105-MVD was significantly correlated with the 2-year overall survival rate (P = 0.014); CD34-MVD was not (P = 0.601). Multivariate analysis confirmed that CD105-MVD was an independent prognostic factor and that CD34-MVD was not.

Conclusion

The anti-CD105 mAb is an ideal instrument to quantify new microvessels in HCC as compared with anti-CD34 mAb. CD105-MVD as compared with CD34-MVD is relevant a significant and independent prognostic indicator for recurrence and metastasis in HCC patients.

Endoglin (CD105) as a prognostic factor in head and neck squamous cell carcinoma

Endoglin (CD105) is a proliferation-associated protein abundantly expressed in angiogenic endothelial cells. Recent studies revealed that CD105 is intensively expressed in tumor vasculature, whereas intratumoral microvessel density (MVD) determined with the use of antibodies to CD105 has been found to be an important prognostic indicator for the outcome in a number of malignancies. In the current study, we investigated endoglin expression and evaluated MVD in 108 patients with head and neck squamous cell carcinoma. Endoglin was intensively expressed in intratumoral blood vessels, whilst lymphatics were rarely positive for CD105. High microvessel density was associated with a more aggressive tumor phenotype, including advanced clinical stage (p = 0.008) and the presence of lymph node metastasis at the time of diagnosis (p = 0.02). When microvessel counts were assessed for their prognostic values (high vs low MVD), there was a statistically significant difference in the overall survival among patients with tumors of the oral cavity and larynx (p < 0.001) and in the disease-free survival among patients with tumors of the lower lip (p = 0.01). The prognostic impact of microvessel density was not dependent on clinical stage or lymph node status. The results of the current study suggest that CD105 is a promising target for tumor imaging and prognosis.

Clinicopathologic significance of CD105 expression in squamous cell carcinoma of the hypopharynx

BACKGROUND

Induction of angiogenesis is a key process in tumor growth and metastasis. We studied the CD105 (endoglin) and vascular endothelial growth factor (VEGF) in hypopharyngeal cancer to evaluate their clinicopathologic significance.

METHODS

Seventy-three patients who underwent complete excision of hypopharyngeal cancer were included in this study. Clinicopathologic data were collected retrospectively. Immunohistochemical analysis was performed with antibodies of CD105 and VEGF. Positive-stained microvessels for CD105 were counted on hot spots of tumors. The staining intensity for VEGF was also evaluated.

RESULTS

High expression of CD105 correlated significantly with positive nodal metastasis (p < .001) and TNM stage (p < .01). High expression of VEGF correlated significantly with advanced tumor (T) classification (p < .01). The overall 5-year survival rate was worse in patients with higher CD105 expression (p < .001), advanced TNM stage (p < .01), advanced T classification (p < .01), and positive nodal metastasis (p < .001). Furthermore, Cox regression analysis revealed that CD105 expression in microvessels of tumor tissue, advanced T classification, and nodal status were independent factors for survival.

CONCLUSION

Our results suggest that expression of CD105 is a useful predictive prognostic factor in hypopharyngeal cancer.

Prognostic significance of VEGF immunohistochemical expression and tumor angiogenesis in head and neck squamous cell carcinoma

PURPOSE

Tumor angiogenesis is crucial for both the growth of the primary tumor and the development of metastases. Among the factors causing tumor angiogenesis, vascular endothelial growth factor (VEGF) is considered as a leading candidate. We aimed to assess the prognostic significance of VEGF and tumor angiogenesis in head and neck squamous cell carcinoma (HNSCC).

METHODS

We performed a retrospective study of 69 patients with HNSCC, in order to investigate whether VEGF immunohistochemical expression and tumor angiogenesis correlate with clinicopathological parameters and outcome. Tumor angiogenesis was estimated by determining microvessel density (MVD), and VEGF expression was assessed quantitatively.

RESULTS

Vascular endothelial growth factor and MVD correlated statistically significant with the clinical stage, but not with the presence of lymph node metastasis at the time of diagnosis. Tumors located in the oral cavity and larynx more often expressed high VEGF immunostaining compared with tumors located in the lower lip. High VEGF expression was associated with higher clinical stage and worse overall survival in this cohort of patients.

CONCLUSIONS

Vascular endothelial growth factor expression may have prognostic significance for patients with HNSCC.

Endoglin (CD105) expression in head and neck basaloid squamous cell carcinoma

CONCLUSIONS

This comparison of neo-angiogenesis performed by analysing CD105 expression seems to suggest that the biological behaviour of head and neck BSCCs is similar to that of site- and stage-matched conventional SCCs.

OBJECTIVE

Basaloid squamous cell carcinoma (BSCC) is an uncommon, high-grade biomorphic variant of SCC with a predilection for the head and neck region. It is a matter of controversy whether the biological and clinical behaviour of BSCC is more aggressive than that of SCC. Angiogenesis is essential for tumour growth. It has been established that endothelial cells of tumour-associated neovasculature proliferate more rapidly than endothelial cells of normal tissue. Endoglin (CD105) has been shown to be a useful marker for identifying proliferating endothelium involved in tumour angiogenesis. The aim of this study was to investigate the expression of CD105 in head and neck BSCCs and to compare it with that in SCCs.

MATERIAL AND METHODS

Nine head and neck BSCCs (five cases in the larynx, three in the tongue and one in the tonsil) were considered. A group of nine site- and stage-matched SCCs was examined simultaneously. For each sample, CD105 reactivity was evaluated immunohistochemically. The mean area fraction (percentage of fields occupied by vessels), the percentage of vessel-presenting fields and the vessel density were considered.

RESULTS

The median values of the mean area fraction were 1.01% and 0.9% in BSCCs and SCCs, respectively. The median values of the percentage of vessel-presenting fields were 57.5% and 46.67% in BSCCs and SCCs, respectively. The median values of vessel density were 2.07% and 1.58% in BSCCs and SCCs, respectively. Statistical analysis did not disclose any significant differences between BSCCs and SCCs for any of the above-mentioned parameters.

Prognostic relevance of CD105+ microvessel density in HNSCC patient outcome

Angiogenesis is essential for the development and progression of malignant tumours, and there is increasing evidence that microvessel density (MVD) can be considered an indirect marker of neo-angiogenesis. However, there is still disagreement concerning the clinical relevance and prognostic significance of MVD in head and neck squamous cell carcinomas (HNSCCs). MVD was evaluated in 127 HNSCC patients by means of immunohistochemistry using monoclonal antibodies (mAbs) against CD34 and CD105 (endoglin), which has recently been described as a potent marker of neo-vascularisation in various malignancies. MVD was expressed as the mean number of vessels/mm2. The mean CD34+ and CD105+ MVD values were significantly higher in T3-T4 tumours and those in an advanced clinical stage; furthermore, CD105+ MVD was significantly higher in N+ tumours. The patients with a high CD105+ MVD had a significantly shorter disease-free and overall survival; CD34+ MVD was not associated with survival. Similarly, in the subset of lymph-node negative patients, higher CD105+ MVD values were significantly associated with either OS and DFS. Multivariate analysis showed that a high CD105+ MVD was the only independent marker of tumour recurrence or death. Our data suggest that CD105+ MVD may represent an additional prognostic factor in HNSCC patients providing more accurate data for the determination of prognosis and management in the subset of lymph node negative patients.

Clinicopathological and prognostic implications of endoglin (CD105) expression in hepatocellular carcinoma and its adjacent non-tumorous liver

AIM: The expression pattern of endoglin (CD105) in hepatocellular carcinoma (HCC) has not been reported so far. We hypothesized that CD105 could differentially highlight a subset of microvessels in HCC, and intratumoral microvessel density (IMVD) by CD105 immunostaining (IMVD-CD105) could provide better prognostic information than IMVD by CD34 immunostaining (IMVD-CD34).

METHODS: Paraffin blocks of tumor and adjacent non-tumorous liver tissues from 86 patients who underwent curative resection of HCC were used for this study. Serial sections were stained for CD105 and CD34, respectively, to highlight the microvessels. IMVD was counted according to a standard protocol.

RESULTS: In the HCC tissues, CD105 was either negatively or positively stained only in a subset of microvessels. In contrast, CD34 showed positive and more extensive microvessel staining in all cases examined. However, in the adjacent non-tumorous liver sections, CD105 showed a diffuse pattern of microvessel staining in 20 of 86 cases, while CD34 showed negative or only focal staining of the sinusoids around portal area. Correlation with clinicopathological data demonstrated that lower scores of IMVD-CD105 were found in larger sized tumors [mean 41.4/0.74 mm² (>5 cm tumor) vs 65.9/0.74 mm² (≤5 cm tumor), P = 0.043] and more aggressive tumors, as indicated by venous infiltration [36.8/0.74 mm² (present) vs 64.2/0.74 mm² (absent), P = 0.020], microsatellite nodules [35.1/0.74 mm² (present) vs 65.9/0.74 mm² (absent), P = 0.012], and advanced TNM tumor stage [38.8/0.74 mm² (stage 3 or 4) vs 68.3/0.74 mm² (stage 1 or 2), P = 0.014]. No prognostic significance was observed when median values were used as cut-off points using either IMVD-CD105 or IMVD-CD34. However, the presence of the diffuse pattern of CD105 expression in the adjacent non-tumorous liver tissues predicted a poorer disease-free survival (median 8.6 vs 21.5 mo, P = 0.026).

CONCLUSION: Our data demonstrate that a lower IMVD-CD105 is associated with larger and more aggressive tumors. In this study, IMVD-CD105 did not provide significant prognostic information. However, active angiogenesis as highlighted by diffuse CD105 staining of the microvessels in the adjacent non-tumorous liver tissues is predictive of early recurrence.

Highlights on endoglin (CD105): from basic findings towards clinical applications in human cancer

Antibody targeting of tumor-associated vasculature is a promising therapeutic approach in human cancer; however, a specific cell membrane marker for endothelial cells of tumor vasculature has not been discovered yet. Endoglin (CD105) is a cell-surface glycoprotein most recently identified as an optimal indicator of proliferation of human endothelial cells. The finding that CD105 is over-expressed on vascular endothelium in angiogenetic tissues has prompted several pre-clinical studies designed to get a deeper understanding on the role of CD105 in angiogenesis, and to evaluate the most appropriate clinical setting(s) to utilize CD105 as a therapeutic target. In this review, the foreseeable clinical applications of CD105 in human cancer are discussed.

The quantification of angiogenesis in relation to metastasis in oral cancer: a review

Tumours need vessels to grow into clinically significant dimensions, and to metastasize. Varying results have been reported for the relation between angiogenic activity in oral carcinomas, and the occurrence of metastasis. Quantification of microvessels in tissue sections is mostly used to assess angiogenesis, but appears subject to biases as reflected in contradicting reports. Especially the choice of immunohistochemical staining technique appears pivotal. Although microvessel density measurements (MVD) appear promising for other tumour types, in oral carcinomas no unambiguous relation could be established. Furthermore, MVD assessment appears more elaborate than expected. New, more time efficient techniques may replace MVD as we know it.

Endoglin (CD105): a powerful therapeutic target on tumor-associated angiogenetic blood vessels

Among surface molecules expressed on endothelial cells, endoglin (CD105) is emerging as a prime vascular target for antiangiogenetic cancer therapy. CD105 is a cell membrane glycoprotein mainly expressed on endothelial cells and overexpressed on tumor-associated vascular endothelium, which functions as an accessory component of the transforming growth factor -beta receptor complex and is involved in vascular development and remodelling. Quantification of intratumoral microvessel density by CD105 staining and of circulating soluble CD105 has been suggested to have prognostic significance in selected neoplasias. In addition, the potential usefulness of CD105 in tumor imaging and antiangiogenetic therapy has been well documented utilizing different animal models.