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

Establishment and characterization of patient tumor-derived head and neck squamous cell carcinoma xenografts

The overall purpose of this study was to establish human head and neck squamous cell carcinoma (HNSCC) xenografts in mice by transplantation of surgical tumor tissue and to characterize the growth, histologic and vascular properties of these xenografts. Primary surgical specimens of HNSCC were xenografted into eight-to-twelve week old severe combined immunodeficiency (SCID) mice. Histologic features of primary HNSCC specimens, initial and established xenografts were compared for tumors established from three different head and neck subsites, namely, oral cavity, larynx and base of tongue (one tumor per site). Growth rates of xenografts were compared along with magnetic resonance imaging (MRI) measures of tumor vascularity and correlative CD31-immunostaining. Initial and established xenografts from all three sites demonstrated a squamous phenotype similar to the original patient tumor histology. Established xenografts of oral cavity and larynx exhibited increased keratinization (H&E) compared to initial xenografts and the primary tumor. No differences in tumor growth rates were observed between established xenografts from the different subsites. Xenografts established from SCC of the larynx exhibited increased microvessel density and lumen area (CD31 staining) along with enhanced permeability to the MR contrast agent compared to oral cavity and base of tongue tumors. Our results show that the combination of non-invasive imaging along with histologic evaluation of patient tumor xenografts offers a valuable platform for preclinical investigations in head and neck cancer. However, it is important to recognize the influence of tumor-host interactions on the histologic phenotype of transplanted tumors.

Clinical significance of vascular endothelial growth factor expression in patients with carcinoma of the mouth floor and tongue

BACKGROUND/AIM

Although there are several types of malignant oral cancers, more than 90% of all diagnosed oral cancers are squamous cell carcinoma (OSCC). Angiogenesis is a cascade-like mechanism which is essential for tumor growth and metastasis. Therefore, vascular endothelial growth factor (VEGF) expression in OSCC and its effect on clinicopathological characteristics and prognosis is of major interest. So far researches have shown that increased expression of this gene, in other words enhanced sinthesis of this protein (VEGF), independently on other factors, increases a chance for local relapse, and distant metastasis. Consequently, patients with OSCC have poor disease-free survival, as well as poor overall survival. The aim of the study was to determine clinical significance of VEGF expression in patients with stage II and III OSCC.

METHODS

This retrospective study analysed 40 patients who had been operated for OSCC of their tongue and the mouth floor. Of these patients, some had stage II and III OSCC with histological grade, G1-G3 and nuclear grade Ng1-Ng3. Two high quality tissue samples were obtained and immunohistochemical expression of VEGF was quantitatively determined by using high microscope amplification. The value of VEGF expression of 20% was rated as significant expression, whereas tumor cells reactivation less than 20% was considered very low or no expression at all. The patients were followed up for a 3-year period.

RESULTS

The obtained results showed that 11 (17.5%) patients had VEGF expression less than 20% and 29 (82.5%) above 20%. A statistical significance was immanent with positive nodal status (p < 0.05) and disease stage (p < 0.05). No statistical correlation was found between the level of VEGF expression and histological and nuclear grade, tumor size, disease relapse or patients overall survival.

CONCLUSION

Inspite the controversy about the prognostic relevance of VEGF our results as well as the results of previous studies, suggest that the expression of VEGF is not reliable as a clinical parameter for the prognosis and disease outcome but it is one of the important factors for the disease progression.

Immunotherapy of head and neck cancer: current and future considerations

Patients with head and neck squamous cell carcinoma (HNSCC) are at considerable risk for death, with 5-year relative survival rates of approximately 60%. The profound multifaceted deficiencies in cell-mediated immunity that persist in most patients after treatment may be related to the high rates of treatment failure and second primary malignancies. Radiotherapy and chemoradiotherapy commonly have severe acute and long-term side effects on immune responses. The development of immunotherapies reflects growing awareness that certain immune system deficiencies specific to HNSCC and some other cancers may contribute to the poor long-term outcomes. Systemic cell-mediated immunotherapy is intended to activate the entire immune system and mount a systemic and/or locoregional antitumor response. The delivery of cytokines, either by single cytokines, for example, interleukin-2, interleukin-12, interferon-γ, interferon-α, or by a biologic mix of multiple cytokines, such as IRX-2, may result in tumor rejection and durable immune responses. Targeted immunotherapy makes use of monoclonal antibodies or vaccines. All immunotherapies for HNSCC except cetuximab remain investigational, but a number of agents whose efficacy and tolerability are promising have entered phase 2 or phase 3 development.

[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.

PET monitoring of therapy response in head and neck squamous cell carcinoma

In the Western world, more than 90% of head and neck cancers are head and neck squamous cell carcinomas (HNSCCs). The most appropriate treatment approach for HNSCC varies with the disease stage and disease site in the head and neck. Concurrent chemoradiotherapy has become a widely used means for the definitive treatment of locoregionally advanced HNSCC. Although this multimodality treatment provides higher response rates than radiotherapy alone, the detection of residual viable tumor after the end of therapy remains an important issue and is one of the major applications of (18)F-FDG PET. Studies have shown that negative (18)F-FDG PET or PET/CT results after concurrent chemoradiotherapy have a high negative predictive value (>95%), whereas the positive predictive value is only about 50%. However, when applied properly, FDG PET/CT can exclude residual disease in most patients, particularly patients with residual enlarged lymph nodes who would otherwise undergo neck dissection. In contrast to other malignancies, data are limited on the utility of (18)F-FDG PET for monitoring the response to induction chemotherapy in HNSCC or for assessing treatment response early during the course of definitive chemoradiotherapy. The proliferation marker (18)F-3'-deoxy-3'fluorothymidine is currently under study for this purpose. Beyond standard chemotherapy, newer treatment regimens in HNSCC take advantage of our improved understanding of tumor biology. Two molecules important in the progression of HNSCC are the epidermal growth factor receptor and the vascular endothelial growth factor (VEGF) and its receptor VEGF-R. Drugs attacking these molecules are now under study for HNSCC. PET probes have been developed for imaging the presence of these molecules in HNSCC and their inhibition by specific drug interaction; the relevance of these probes for response assessment in HNSCC will be discussed. Hypoxia is a common phenomenon in HNSCC and renders cancers resistant to chemo- and radiotherapy. Imaging and quantification of hypoxia with PET probes is under study and may become a prerequisite for overcoming chemo- and radioresistance using radiosensitizing drugs or hypoxia-directed irradiation techniques and for monitoring the response to these techniques in selected groups of patients. Although (18)F-FDG PET/CT will remain the major clinical tool for monitoring treatment in HNSCC, other PET probes may have a role in identifying patients who are likely to benefit from treatment strategies that include biologic agents such as epidermal growth factor receptor inhibitors or VEGF inhibitors.

Low-level expression of microRNAs let-7d and miR-205 are prognostic markers of head and neck squamous cell carcinoma

Small noncoding microRNAs (miRNAs) have been shown to be abnormally expressed in every tumor type examined. The importance of miRNAs as potential cancer prognostic indicators is underscored by their involvement in the regulation of basic cellular processes such as cell proliferation, differentiation, and apoptosis. In this study, miRNA expression profiles of head and neck squamous cell carcinoma (HNSCC) tumor and adjacent normal tissue were examined by microarray analysis and validated by quantitative TaqMan real-time polymerase chain reaction. Using TaqMan real-time polymerase chain reaction we measured the quantitative associations between a subset of miRNAs identified on microarrays in primary tumors at diagnosis and cancer survival in a cohort of 104 HNSCC patients undergoing treatment with curative intent. The majority of miRNAs exhibiting altered expression in primary human HNSCC tumors (including miR-1, miR-133a, miR-205, and let-7d) show lower expression levels relative to normal adjacent tissue. In contrast, hsa-miR-21 is frequently overexpressed in human HNSCC tumors. Using univariate and multivariable statistical models we show that low levels of hsa-miR205 are significantly associated with loco-regional recurrence independent of disease severity at diagnosis and treatment. In addition, combined low levels of hsa-miR-205 and hsa-let-7d expression in HNSCC tumors are significantly associated with poor head and neck cancer survival Our results show that miRNA expression levels can be used as prognostic markers of head and neck cancer.

Mast cells and angiogenesis in oral malignant and premalignant lesions

Mast cell contribution to neoangiogenesis during tumorigenesis in oral squamous cell carcinoma is not determined yet. Objectives: To associate numerical mast cell density (MCD) to numerical microvessel density (MVD) during the progression of oral leukoplakia without dysplasia and leukoplakia with dysplasia to squamous cell carcinoma (OSCC). Materials and methods: MVD was analysed immunohistochemically (mouse monoclonal anti-human CD34) in 49 paraffin-embedded specimens, 35 OSCCs, 9 leukoplakias and 5 normal oral tissues. Toluidine blue counterstaining revealed mast cells. MCD and MVD were assessed at the same optical field. Results: MVD increased between: normal oral mucosa, dysplasia (p=0.004), OSCC (p=0.001), leukoplakia and OSCC (p=0.041). MCD increased between: normal oral mucosa, dysplasia (p=0.003), OSCC (p=0.000), leukoplakia and OSCC (p=0.007). MVD was found to depend on MCD (p=0.000) in a percent 28.3% (power curve fit model). Conclusions: Mast cells are attracted at the lesion site and may turn on an angiogenic switch during tumorigenesis in OSCC.

The expression of vascular endothelial growth factor and its receptors in port-wine stains

OBJECTIVE

To investigate the expression of vascular endothelial growth factor (VEGF) and its receptor (VEGF-R2) in port-wine stains (PWSs).

DESIGN

An immunohistochemistry (IHC) study on formalin-fixed, paraffin-embedded specimens.

METHODS

Representative sections from surgical resection specimens of 12 PWS patients and 12 control specimens stained with routine IHC by using polyclonal anti-VEGF and anti-VEGF-R2 antibodies. Slides were evaluated semiquantitatively for the intensity of staining for VEGF and VEGF-R2 by using a scoring system varying from 0 to 3+.

RESULTS

PWS specimens showed statistically significant overexpression of both VEGF and VEGF-R2 molecules when compared with control specimens (P < 0.005).

CONCLUSIONS

VEGF and its receptor may play an important role in the pathogenesis of PWS. It is possible that PWS may progress by hyperplasia in addition to hypertrophy. VEGF-R blockade may have a potential role as a targeted approach in the treatment of this disfiguring condition in the future.

Targeting angiogenesis in head and neck cancer

Tumor angiogenesis is a hallmark of advanced cancers and an attractive treatment target in multiple solid tumors. In the past 5 years anti-angiogenic therapies have seen a rapid ascent into mainstream clinical practice. For head and neck cancer (HNC), definitive evidence in the form of a pivotal trial is still pending. Nevertheless, preclinical and early clinical data support a central role of angiogenesis for HNC: up to 90% of HNCs express angiogenic factors such as vascular endothelial growth factor (VEGF) and the respective receptors (VEGFR1-3), and multiple studies support the prognostic implications of angiogenic markers for this tumor. Contrary to concerns that anti-angiogenic therapies could increase hypoxia and thereby treatment resistance, anti-angiogenic therapies in preclinical models appear to overcome resistance and preclinically synergize with traditional therapies, eg, radiation. Clinical use of anti-angiogenic agents for HNC, including bevacizumab, sorafenib, sunitinib, and others, is currently limited to clinical trials, and several larger trials are still ongoing. Single-agent anti-angiogenic drugs so far have not shown activity in unselected HNC patients, with a response rate of less than 4% for the small molecule anti-angiogenics sorafenib and the investigational agent SU5416. On the other hand, combinations of anti-angiogenic drugs with other treatments (analogous to other solid tumors) appear promising; for example, the combination of bevacizumab with the EGFR inhibitor erlotinib showed a response rate of 14.6%. Studies of bevacizumab with chemotherapy (phase III Eastern Cooperative Oncology Group [ECOG] trial) and in combination with chemoradiation are currently ongoing. The side effect profile is comparable to what has been observed in other tumor types and include hypertension, proteinuria, and thrombotic and hemorrhagic events. With the intense research effort preclinically and clinically, and some encouraging early results, anti-angiogenic therapies and biomarkers appear to be poised to play an important role in the treatment of HNC in the near future.

Assessment of bevacizumab conjugated to Cy5.5 for detection of head and neck cancer xenografts

Optical fluorescent technology has the potential to deliver real time imaging of cancer into the operating room and the clinic. To determine the efficacy of fluorescently labeled anti-vascular endothelial growth factor (VEGF) antibody to be used as a cancer specific optical contrast agent to guide surgical resections, we evaluated the sensitivity and specificity of this agent to detect microscopic residual disease in a preclinical model of head and neck squamous cell carcinoma (HNSCC). Using a flank murine model, mice were xenografted with SCC-1 tumor cells and injected with anti-VEGF antibody (bevacizumab) conjugated to an optically active fluorophore (Cy5.5). Tumors underwent sub-total resections and were assessed for the presence of residual disease by fluorescent stereomicroscopy. Expected positive and negative biopsies were taken according to the presence or absence of fluorescence, respectively. Histology was used to confirm the presence or absence of disease. Biopsies taken from areas of fluorescence within the wound bed (n=18) were found to be histologically malignant in all but one biopsy. Samples taken from a non-fluorescing tumor bed (n=15) were found to be histologically benign in 11 of 15. These findings correlated with a sensitivity and specificity of 80.9% and 91.7%, respectively. This data supports previous data presented by this group and supports further investigation of fluorescently labeled anti-tumor antibodies to detect disease in the surgical setting.

Tumor lymphangiogenesis correlates with lymph node metastasis and clinicopathologic parameters in oral squamous cell carcinoma

BACKGROUND

Lymphatic vessel density (LVD) and microvessel density (MVD) are important parameters for assessing the malignant potential of tumors and patient survival. In this report, the authors defined LVD as the density of D2-40-positive lymphatic vessels and MVD as the density of CD105-positive microvessels per unit area of tissue. It was reported previously that vascular endothelial growth factor C (VEGF-C) is a major modulator of LVD and MVD. The objectives of this study were to clarify the clinical and prognostic significance of both LVD and MVD in oral squamous cell carcinoma (OSCC) and to elucidate the lymphangiogenic and angiogenic activities of VEGF-C in cancer tissues.

METHODS

In total, 110 OSCC tissue samples were evaluated for LVD, MVD, and expression of VEGF-C using immunohistochemistry. Correlations among these parameters and clinicopathologic factors were examined.

RESULTS

LVD was significantly higher in tumors that had very high expression of VEGF-C compared with tumors that had no/weak expression of VEGF-C. LVD correlated well with lymph node metastasis (P < .001). MVD was correlated significantly with positive lymph node metastasis (P < .001) but not with VEGF-C expression. In contrast, high expression of VEGF-C was correlated significantly with advanced tumor status (P = .041). Survival rates were lower in patients who had higher LVD (P < .001), higher MVD (P = .0028), and strong VEGF-C expression (P = .048).

CONCLUSIONS

Lymphangiogenesis predominantly influenced metastasis-free survival. The current results suggested that LVD is a more useful tool than MVD and VEGF-C for deciding on therapeutic strategies in patients with OSCC.

The potential role of intrinsic hypoxia markers as prognostic variables in cancer

Tumor hypoxia is related to tumor progression and therapy resistance, which leads to poor patient outcome. It has been suggested that measuring the hypoxic status of a tumor helps to predict patient outcome and to select more targeted treatment. However, current methods using needle electrodes or exogenous markers have limitations due to their invasiveness or necessity for preinjection. Recent studies showed that hypoxia-regulated genes could be alternatively used as endogenous hypoxia markers. This is a review of 15 hypoxia-regulated genes, including hypoxia-inducible factor-1 and its targets, and their correlation with tumor hypoxia and patient outcome from 213 studies. Though most of the studies showed significance of these genes in predicting prognosis, there was no definitive prognostic and hypoxia marker. In conclusion, this review suggests the need for further studies with standardized methods to examine gene expression, as well as the use of multiple gene expressions.

Vascular Endothelial Growth Factor Expression Predicts Outcome after Primary Radiotherapy for Head and Neck Squamous Cell Cancer

AIMS

To establish whether the expression of vascular endothelial growth factors (VEGFs) predicts prognosis in patients treated with primary radiotherapy for cancers of the upper aerodigestive tract.

MATERIALS AND METHODS

A retrospective analysis was undertaken of VEGF and VEGF-D expression in tumour tissue in pre-treatment biopsies from 27 patients who had been treated with primary radiotherapy for stage II-IV squamous head and neck carcinomas. Serial sections (4 microm) were cut from formalin-fixed, paraffin-embedded specimens and stained with monoclonal antibodies using standard immunoperoxidase methods. Two independent investigators assessed the staining intensity in a randomised, blind manner. Both negative and positive controls (placenta and/or tonsil) were included in the staining procedure. All patients were followed for a minimum of 5 years, or until death. Local control and overall survival were taken as end points for the comparative analysis between patients whose tumours expressed low levels and those that expressed high levels of the two growth factors. Comparisons were made using the Log-rank test with Kaplan-Meier actuarial survival analysis.

RESULTS

In patients with tumours expressing low levels of VEGF, 5-year local control was seen in 75% compared with 18% for those with high levels; overall survival was 75 and 23%, respectively. For those with low levels of VEGF-D, 5-year local control was 64% compared with 17% for those with high levels; overall survival was 58 and 20%, respectively.

CONCLUSION

Our results suggest that the expression of endothelial growth factors in squamous head and neck cancers may predict outcome after radiotherapy.

Prognostic significance of vascular endothelial growth factor protein levels in T1-2 N0 laryngeal cancer treated with primary radiation therapy

BACKGROUND

The purpose of this study was to assess the prognostic value of vascular endothelial growth factor protein levels in a large cohort of patients with T1-T2 N0 laryngeal cancer treated with primary radiation therapy (XRT).

METHODS

Primary tumor specimens from a cohort of 123 patients with T1-T2 N0 laryngeal cancer treated with XRT between 1975 and 2000 were constructed into a tissue microarray. Clinical prognostic factors included age, sex, T classification, and tumor subsite. Molecular prognostic factors included vascular endothelial growth factor, epidermal growth factor receptor, and p53 expression, determined by using immunohistochemistry on tissue microarrays. The association between vascular endothelial growth factor status, covariables, and outcome was assessed.

RESULTS

With a median follow-up of 9.9 years, 32 (26%) were diagnosed with local relapse (5-year local relapse-free rate, 70.4%). T2 tumor stage (31.7%) was a significant predictor of local relapse (relative risk [RR], 1.71; 95% confidence interval [CI], 1.21-2.43; P<.05). Positive expression of vascular endothelial growth factor, epidermal growth factor receptor, and p53 were: 8.5%, 58.7%, and 36.4%, respectively. In univariate analysis, vascular endothelial growth factor positivity was a significant predictor of overall survival (RR = 1.62; 95% CI, 0.99-2.42; P = .05). In multivariate analysis, positive vascular endothelial growth factor status maintained significant correlation with overall survival (RR, 2.79; 95% CI, 1.49-4.95; P = .002).

CONCLUSIONS

Vascular endothelial growth factor positivity appeared to be a significant predictor of overall survival in a multivariate model. Further evaluation of vascular endothelial growth factor-positive laryngeal cancers treated with primary XRT is warranted.

Vascular endothelial growth factor pharmacogenetics: a new perspective for anti-angiogenic therapy

The pharmacogenetic approach to anti-angiogenic therapy should be considered a possible strategy for many pathological conditions with high incidence in Western countries, including solid tumors, age-related macular degeneration or endometriosis. While pharmacogenetic studies are building stronger foundations for the systematic investigations of phenotype–genotype relationships in many research and clinical fields of medicine, pharmacogenetic data regarding anti-angiogenic drugs are still lacking. Here we review preclinical and clinical genetic studies on angiogenic determinants such as vascular endothelial growth factor and vascular endothelial growth factor receptor-2. We suggest that pharmacogenetic profiling of patients who are candidates for the currently available anti-angiogenic agents targeting vascular endothelial growth factor and vascular endothelial growth factor receptor-2 may aid the selection of patients on the basis of their likelihood of responding to the drugs or suffering from toxicity.

Over-expression of p53 mutants in LNCaP cells alters tumor growth and angiogenesis in vivo

This study has investigated the impact of three specific dominant-negative p53 mutants (F134L, M237L, and R273H) on tumorigenesis by LNCaP prostate cancer cells. Mutant p53 proteins were associated with an increased subcutaneous "take rate" in NOD-SCID mice, and increased production of PSA. Tumors expressing F134L and R273H grew slower than controls, and were associated with decreased necrosis and apoptosis, but not hypoxia. Interestingly, hypoxia levels were increased in tumors expressing M237L. There was less proliferation in F134L-bearing tumors compared to control, but this was not statistically significant. Angiogenesis was decreased in tumors expressing F134L and R273H compared with M237L, or controls. Conditioned medium from F134L tumors inhibited growth of normal human umbilical-vein endothelial cells but not telomerase-immortalized bone marrow endothelial cells. F134L tumor supernatants showed lower levels of VEGF and endostatin compared with supernatants from tumors expressing other mutants. Our results support the possibility that decreased angiogenesis might account for reduced growth rate of tumor cells expressing the F134L p53 mutation.

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.