The tumour stroma of oral squamous cell carcinomas show increased vascularity compared with adjacent host tissue

Vascular patterns in basal cell carcinoma: Dermoscopic, confocal and histopathological perspectives

Basal cell carcinoma (BCC) is the most prevalent skin cancer in the Caucasian population. A variety of different phenotypic presentations of BCC are possible. Although BCCs rarely metastasize, these tumors commonly destroy underlying tissues and should therefore be treated promptly. As vascular formation and angiogenesis are indicators of tumor development and progression, the presence of blood vessels, their morphology and architecture are important markers in skin lesions, providing critical information towards pathogenesis and diagnosis. BCC commonly lacks pigmentation, therefore it is important to emphasize the usefulness of vascular feature detection, recognition, quantification and interpretation. To answer the question of whether vascular patterns observed on dermoscopy, reflectance confocal microscopy (RCM) and histopathology might reflect the biologic behavior of BCCs, we undertook this review article. Several studies have sought, by various means, to identify vascular features associated with the more aggressive BCC phenotypes. Dermoscopic vascular pattern assessment can facilitate diagnostic discrimination between BCC subtypes, more aggressive BCCs displaying less or no pink coloration and a relative absence of central tumor vessels. RCM, a novel, non-invasive imaging technique, allows for the quantification of blood vessel size, density, and flow intensity in BCCs. BCCs are distinguished on RCM chiefly by vessels that branch and intertwine between neoplastic aggregates, a pattern strongly reflecting tumor neo-angiogenesis. The analysis of these vascular morphological and distribution patterns can provide further support in the diagnosis, assessment, or monitoring of BCCs. Histopathology shows significantly higher microvessel densities in the peritumoral stroma of BCCs, when compared to normal skin or benign tumors. This angiogenic response in the stroma is associated with local aggressiveness, therefore the quantification of peritumoralmicrovessels may further assist with tumor evaluation. How dermoscopy and RCM vascular patterns in BCC correlate with histopathological subtype and thus help in discriminating aggressive subtypes definitely deserves further investigation.

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 CD34 and maspin in ameloblastoma from a West African subpopulation

Ameloblastoma is a locally invasive odontogenic tumor with a high recurrence rate. Its local invasiveness is aided by angiogenesis, which can be correctly estimated by CD34. On the other hand, maspin decreases the local invasive and metastatic capability of cancer cells and functions as an angiogenesis inhibitor. We aim to assess the association between maspin expression and microvessel density in ameloblastoma. Twenty-five formalin-fixed paraffin-embedded (FFPE) blocks of ameloblastoma cases were prepared for antibody processing to CD34 and maspin. Positive immunohistochemical staining was marked by brown cytoplasmic/membrane coloration for CD34 and by nuclear/cytoplasmic coloration for maspin. At the ×40 magnification, we counted blood vessels in two areas of dimension; 300 × 400 μm (area A) and 150 × 200 μm (area B) adjacent to the tumor region to assess relative dispersion of the vessels bordering the tumor. The overall approximate microvessel density (MVD) for area A = 11 (minimum 2, maximum 21) and that for area B = 5 (minimum 1, maximum 10). The MVD in the area A of plexiform ameloblastoma was similar to that of the unicystic, while the hemangiomatous variant had the highest MVD for area A. Maspin positivity was present only in the cytoplasm of ameloblast, stellate reticulum, and the fibrous connective tissue in varying proportions. There was no evidence of the anti-angiogenesis effect of maspin in ameloblastoma from this study. The significance of cytoplasmic localization of maspin in the ameloblasts and stellate reticulum cells needs further investigation.

Microvessel Density Is Associated with VEGF and α-SMA Expression in Different Regions of Human Gastrointestinal Carcinomas

Tumor angiogenesis is known to be regulated by growth factors secreted by host and tumor cells. Despite the importance of tumor vasculature and angiogenic heterogeneity in solid tumors, few studies have compared the vasculature in different regions of human cancer. Blood vessels from different regions of carcinomas might have morphofunctional implications in tumor angiogenesis. In the present study, therefore, we have examined the relationship between microvascular density (MVD) and vascular endothelial growth factor (VEGF) expression and alpha smooth muscle actin (α-SMA) expression in the center of the tumor (CT), periphery (P) and metastasis (M) regions from gastrointestinal carcinomas (GITC), as well as the association of MVD with clinicopathological factors. Surgically resected specimens corresponding to the CT, P and M from 27 patients were examined for FVIII, VEGF and α-SMA by immunohistochemistry. The MVD was not significantly different in the CT, P and M regions from GITC. The MVD in the VEGF positive group was significantly higher than in the VEGF negative group (CT, p = 0.034; P, p = 0.030; M, p = 0.032). The MVD as a function of α-SMA expression was also significantly higher in the CT and P region compared to the M region (p = 0.0008). In conclusion, the MVD association with VEGF and α-SMA expression, might indicate an increase of the number of neoformed and preexisting blood vessels uniformly or partially covered by pericytes in different regions of GITC, suggesting that not only MVD and VEGF are important parameters to the tumor vasculature, but also blood vessels maturation is a crucial factor for gastrointestinal tumor angiogenesis regulation and possible target of vascular therapy.

Differences in the vascular patterns of basal and squamous cell skin carcinomas explain their differences in clinical behaviour

Tumour angiogenesis is essential for tumour growth and appears to play an important role both at the transition from hyperplasia to invasive growth and at a late stage in the dissemination process. Basal cell carcinomas (BCCs) and trichoepitheliomas (TEs) are related tumours that share the properties of invasive growth but without the capacity to metastasize. Squamous cell carcinomas (SCCs) of the skin are derived from a similar cell type and they have both invasive and metastatic potential. The aim of this study was to investigate whether the behaviour of these tumours could be explained by differences in their microvasculature. The study looked both qualitatively and quantitatively at the microvasculature of BCCs (n=50) and TEs (n=33) and compared them with normal skin (n=6) and with SCCs of the skin (n=22). Vessel counts were performed using a standard graticule count method after immunohistochemical staining for CD31. Counts were made of blood vessels in the stroma surrounding the tumour and also for vessels in the body of the tumour. The stromal counts for all the tumour groups differed significantly from normal skin. The SCC counts differed significantly from the counts for the BCCs and TEs. There was no significant difference between the counts for different subtypes of BCC or TE groups. While vessels could be found in the body of the SCCs, none was seen in the nodular BCC or the TE groups. There was no correlation between the vascular density and the depth of invasion. Overall, invasive growth correlated with an angiogenic response in the stroma, while metastatic potential correlated with microvessels being present in the body of the tumour.

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

BACKGROUND

Increasing evidence suggests that endoglin (CD105) is a new powerful marker of neovascularization in solid malignancies. To explain the rating of CD105 expression in 51 squamous cell carcinoma of the oral cavity (SCCOC) we analyzed CD105 expression in tumor tissue and adjacent normal healthy mucosa.

METHODS

Mean CD105 density was quantitated by counting the number of CD105-immunostained blood vessels. The results were compared with clinical parameters like T and N stage, grading, tumor localization, and specific characteristics of patients by means of statistical analysis.

RESULTS

Endoglin expression in tumor tissue was significantly higher than in normal healthy mucosa (p <.001). With the exception of T3 (n = 2), a higher T stage was correlated with higher endoglin expression. No statistical correlation was found in the analysis of patient's age, gender, and tumor localization.

CONCLUSIONS

Endoglin expression is up-regulated in SCCOC compared with normal healthy oral mucosa. Endoglin may have a significant role in the development of SCCOC and might be relatively more specific than commonly used endothelial markers.

'Invading edge vs. inner' (edvin) patterns of vascularization: an interplay between angiogenic and vascular survival factors defines the clinical behaviour of non-small cell lung cancer

Neo-angiogenesis during neoplastic growth involves endothelial mitogenic and migration stimuli produced by cancer or tumour stromal cells. Although this active angiogenesis takes place in the tumour periphery, the process of vessel growth and survival in inner areas and its clinical role remain largely unexplored. The present study compared the microvessel score (MS) as well as the single endothelial cell score (ECS) in the invading edge and in inner areas of non-small cell lung carcinomas (NSCLCs). Three different patterns of vascular growth were distinguished: the edvin (edge vs. inner) type 1, where a low MS was observed in both peripheral and inner tumour areas; the edvin type 2, where a high MS was noted in the invading front but a low MS in inner areas; and the edvin type 3, where both peripheral and inner tumour areas had a high MS. The ECS was high in the invading edge in edvin type 2 and 3 cases and was sharply decreased in both types in inner areas, suggesting that endothelial cell migration is unlikely to contribute to the angiogenic process in areas away from the tumour front. Expression of the vascular endothelial growth factor (VEGF) and of thymidine phosphorylase (TP) was associated with a high MS in the invading edge. VEGF was associated with a high MS in inner areas (edvin 3), while TP expression was associated with edvin type 2, showing that VEGF (and not TP) contributes to the preservation of the inner vasculature. Both edvin type 2 and 3 cases showed an increased incidence of node metastasis, but edvin type 3 cases had a poorer prognosis, even in the N1-stage group. The present study suggests that tumour factors regulating angiogenesis and vascular survival are not identical. A possible method is reported to quantify these two parameters by comparing the MS in the invading edge and inner areas (edvin types). This observation may contribute to the evaluation of the effectiveness of different therapeutic approaches, namely vascular targeting vs. anti-angiogenesis.

Neo-angiogenesis in locally advanced squamous cell head and neck cancer correlates with thymidine phosphorylase expression and p53 nuclear oncoprotein accumulation

Thymidine phosphorylase (Th.P) is an angiogenic factor shown to induce endothelial cell migration and proliferation. On the other hand, loss of wild type p53 function leads to down-regulation of thrombospondin-1, an inhibitor of angiogenesis. In this immunohistochemical study we investigated the intratumoural angiogenesis and thymidine phosphorylase (Th.P) expression in paraffin-embedded bioptical material from 104 locally advanced squamous cell head and neck cancers. The nuclear accumulation of mutant p53 protein and the cytoplasmic expression of bcl-2 protein was also assessed. High vascular grade was observed in 56% and high Th.P tumour cell reactivity in 48% of cases. High microvessel score was associated with an increased percentage of cancer cells expressing thymidine phosphorylase (P = 0.001). Increased p53 nuclear accumulation also correlated with high vascular grade (P = 0.001). High histological grade and absence of bcl-2 overexpression were associated with lymph node involvement (P = 0.002 and P = 0.02 respectively). No correlation of clinically detected lymphadenopathy with angiogenesis and p53 was observed. We conclude that intense neo-angiogenesis in locally advanced squamous cell head neck cancer is a frequent event, which is associated with nuclear p53 accumulation and thymidine phosphorylase overexpression.

Role of nitric oxide in angiogenesis and tumor progression in head and neck cancer

BACKGROUND

Angiogenesis (formation of new blood vessels) is associated with tumor growth and metastasis in patients with solid tumors, including those of the head and neck. Nitric oxide (NO) production may contribute to these processes. We assessed the role of the NO pathway in angiogenesis and tumor progression in patients with head and neck cancer.

METHODS

Biochemical assays were used to measure NO synthase (NOS) activity and cyclic guanosine monophosphate (cGMP) levels in specimens of tumor and normal mucosa obtained from 27 patients. Microvessels in tumor specimens were identified by CD-31-specific immunohistochemical staining. Associations between microvessel densities, levels of NOS, and cGMP were examined by use of two-sided statistical tests. Tumor specimens and human squamous carcinoma A-431 cells were grown as explants on the corneas of rabbits, and the effect of the NOS inhibitor N(omega)-nitro-L-arginine-methyl ester (L-NAME) was tested.

RESULTS

Levels of total NOS, inducible NOS, and cGMP were higher in tumor specimens than in specimens of normal mucosa (all P<.0001). Tumor specimens from patients with lymph node metastases presented a higher total NOS activity (P = .005) and were markedly more vascularized than tumor specimens from patients with no lymph node involvement (P = .0002). Microvessel density at the tumor edge was an independent predictor of metastasis for this series of patients (odds ratio = 1.19; 95% confidence interval = 1.07-2.89; P = .04). A-431 cells and tumor specimens exhibiting high levels of NOS activity induced angiogenesis in the rabbit cornea assay; when NO production was blocked, tumor angiogenesis and growth were repressed.

CONCLUSIONS

The NO pathway appears to play a key role in tumor angiogenesis and spread in patients with head and neck cancer.