Expression of transforming growth factor-alpha, epidermal growth factor receptor and platelet-derived growth factors A and B in oropharyngeal cancers treated by curative radiation therapy

LRG1 and SDR16C5 protein expressions differ according to HPV status in oropharyngeal squamous cell carcinoma

The increasing incidence of oropharyngeal squamous cell carcinoma (OPSCC) is primarily due to human papillomavirus, and understanding the tumor biology caused by the virus is crucial. Our goal was to investigate the proteins present in the serum of patients with OPSCC, which were not previously studied in OPSCC tissue. We examined the difference in expression of these proteins between HPV-positive and -negative tumors and their correlation with clinicopathological parameters and patient survival. The study included 157 formalin-fixed, paraffin-embedded tissue samples and clinicopathological data. Based on the protein levels in the sera of OPSCC patients, we selected 12 proteins and studied their expression in HPV-negative and HPV-positive OPSCC cell lines. LRG1, SDR16C5, PIP4K2C and MVD proteins were selected for immunohistochemical analysis in HPV-positive and -negative OPSCC tissue samples. These protein´s expression levels were compared with clinicopathological parameters and patient survival to investigate their clinical relevance. LRG1 expression was strong in HPV-negative whereas SDR16C5 expression was strong in HPV-positive tumors. Correlation was observed between LRG1, SDR16C5, and PIP4K2C expression and patient survival. High expression of PIP4K2C was found to be an independent prognostic factor for overall survival and expression correlated with HPV-positive tumor status. The data suggest the possible role of LRG1, SDR16C5 and PIP4K2C in OPSCC biology.

Prognostic Value of Microvessel Density in Head and Neck Squamous Cell Carcinoma: A Meta-Analysis

The prognostic value of microvessel density (MVD) in head and neck squamous cell carcinoma (HNSCC) remains disputable. The purpose of this study was to comprehensively determine the prognostic value of MVD in HNSCC. Relevant literatures were identified using PubMed, Embase, and Cochrane Library. A meta-analysis was performed to clarify the prognostic role of MVD in HNSCC patients and different subgroups. A total of 14 eligible articles were included in this meta-analysis. The combined hazard ratio (HR) and 95% confidence interval (95% CI) for overall survival (OS) of 11 studies was 1.663 (1.236-2.237, P = 0.001), and the pooled HR and 95% CI for progression-free survival (PFS) of 7 studies was 2.069 (1.281-3.343, P = 0.003). Subgroup analyses were also performed on different issues, such as regional distribution of patients, age, tumor location, antibody, and treatment strategy. To conclude, high MVD is associated with worse OS and PFS in patients with HNSCC.

Overexpression of Platelet-Derived Growth Factor and Its Receptor Are Correlated with Oral Tumorigenesis and Poor Prognosis in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a cancerous disease with poor prognosis. According to the statistics, the 5-year survival rate has not improved significantly over the past 20 years. The platelet-derived growth factor (PDGF) and its signaling pathway is a key regulator of angiogenesis and tumorigenesis. High level of PDGF and its receptor (PDGFR) have been reported in several types of malignancies. In this study, we investigated the relationship of the molecular expression levels of PDGF and PDGFR with clinicopathological parameters in OSCC. To this end, we measured the mRNA and protein levels of PDGF and PDGFR by real-time quantitative PCR (qRT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA), respectively. We found positive correlations of the mRNA levels of PDGFA, PDGFB, and PDGFRB with lymph node metastasis and poor overall survival (OS). High expression of PDGF, PDGFRA, and PDGFRB were remarkably associated with lymph node metastasis and poor OS, as determined by immunohistochemistry. Preoperative serum levels of PDGF-AA and PDGF-BB had a positive correlation with preoperative platelet count. Elevated serum levels of PDGF-AA. PDGF-BB, and platelet count correlated with lymph node metastasis and an unfavorable outcome. In multivariate Cox regression analysis, PDGFA mRNA, PDGFB mRNA, PDGFRB mRNA, PDGF immunoexpression, PDGFRB immunoexpression, serum PDGF-AA, serum PDGF-BB, and platelet count emerged as significant independent prognostic factors for OS. In vitro, we found that elevated PDGF promotes colony formation, migration, and invasiveness of SAS and OECM-1 cancer cell lines. Our results suggest that the expression level of serum PDGF has the potential to become a useful diagnostic marker for the prognosis of OSCC. In addition, PDGFR should be considered as a potential therapeutic target for OSCC. Furthermore, research should be undertaken to elucidate the role of PDGF and PDGFR regarding the behavior of tumor cells in OSCC.

Prognostic and predictive value of EGFR in head and neck squamous cell carcinoma

EGFR is an extensively studied biomarker in head and neck squamous cell carcinoma (HNSCC). In this review, we discuss the prognostic and predictive role of EGFR in HNSCC, focusing on the different molecular alterations in specific treatment modalities such as radiotherapy alone (RT), combination of surgery, RT and chemotherapy (CT), EGFR inhibitors. We considered EGFR at different molecular levels: protein expression, protein activation, gene copy number, polymorphisms, mutation, EGFRvIII expression and EGFR ligand expression.

Considering RT alone, evidence supports the predictive and prognostic role of high EGFR expression only when evaluated by quantitative assays: this may help select the patients who can mostly benefit from accelerated treatment. Conversely, no predictive biomarkers are available when treatment is a combination of surgery, CT and RT. For this combined treatment, several studies indicate that EGFR expression represents a good prognostic parameter only when measured by a “quantitative” or at least semi-quantitative method. With respect to EGFR inhibitors, neither EGFR expression nor increased gene copy number represent prognostic/predictive factors.

If validated, nuclear EGFR, TGFα levels, EGFR phopshorylation and polymorphisms could represent additional prognostic factors in relation to combination of surgery, CT and RT, while EGFR polymorphisms and high amphiregulin levels could have prognostic value in patients treated with EGFR inhibitors.

The Use of Tyrosine Kinase Inhibitors in Modifying the Response of Tumor Microvasculature to Radiotherapy

The response of the tumor microvasculature to ionizing radiation can be modified to improve tumor control in preclinical mouse models of cancer. Recent studies have shown that a variety of cancer drugs can improve the response of cancers to radiotherapy. Protein tyrosine kinase inhibitors (TKIs) have been shown to enhance radiation-induced destruction of tumor blood vessels. Among these compounds are inhibitors of a broad spectrum of receptor tyrosine kinases (RTKs). Inhibition of RTKs attenuates downstream signaling from various angiogenic growth factors, including vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and fibroblast growth factor (FGF). RTK inhibitors with various specificities against the receptors for VEGF, PDGF, and FGF manifest significant antiangiogenic activities as well. We have shown using tumor vascular window model and tumor growth delay assays that these compounds can enhance tumor radiation response by attacking tumor microvasculature. Furthermore, we have shown that radiation and RTK inhibitors exert their antiangiogenic effect through inhibition of the PI3K/Akt signaling pathway, which results in induction of apoptosis. Our studies have provided a basis for future clinical investigations of combining radiotherapy and RTK inhibitors.

Initial evidence for Sec62 as a prognostic marker in advanced head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a malignancy with an increasing incidence. To aid with the selection of the most appropriate therapy, biomarkers have become a specific research focus. Sec62 is involved in endoplasmic reticulum stress tolerance and cell migration, and has been identified as a novel prognostic marker for non-small cell lung cancer. In addition, Sec62 may be a promising candidate in HNSCC. Pretreatment biopsies of 35 patients with locally advanced HNSCC, who were treated with definitive chemoradiation therapy without prior surgery, were examined for the expression of Sec62 protein, as well as the expression of epidermal growth factor receptor (EGFR), p16 and survivin proteins. Immunohistological results were correlated with patient overall survival (OS) and progression-free survival (PFS) times. In the present patient cohort, 12/35 cases (34%) demonstrated strong and 8/35 cases (23%) moderate Sec62 staining intensity. Additionally, in 11/35 cases (31%), weak staining was observed, and only 4/35 cases (11%) were Sec62-negative. Notably, a high Sec62 protein level was associated with a significantly poorer OS and PFS (P=0.020 and P=0.028, respectively). Furthermore, higher nuclear survivin expression showed a weak trend for poorer OS rate (P=0.079), whilst neither cytoplasmic survivin, EGFR nor p16 influenced OS or PFS significantly. The present study indicated that Sec62 is a promising prognostic marker for HNSCC. Increased Sec62 protein expression may indicate a poorer prognosis in advanced HNSCC. As the present study was focused on patients treated by chemoradiation therapy, further studies with larger patient cohorts and alternative treatment approaches are required in order to define the prognostic value of Sec62 in HNSCC.

Predicting Hub Genes Associated with Cervical Cancer through Gene Co-Expression Networks

Cervical cancer is the third most common malignancy in women worldwide. It remains a leading cause of cancer-related death for women in developing countries. In order to contribute to the treatment of the cervical cancer, in our work, we try to find a few key genes resulting in the cervical cancer. Employing functions of several bioinformatics tools, we selected 143 differentially expressed genes (DEGs) associated with the cervical cancer. The results of bioinformatics analysis show that these DEGs play important roles in the development of cervical cancer. Through comparing two differential co-expression networks (DCNs) at two different states, we found a common sub-network and two differential sub-networks as well as some hub genes in three sub-networks. Moreover, some of the hub genes have been reported to be related to the cervical cancer. Those hub genes were analyzed from Gene Ontology function enrichment, pathway enrichment and protein binding three aspects. The results can help us understand the development of the cervical cancer and guide further experiments about the cervical cancer.

Role of EGFR as a prognostic factor for survival in head and neck cancer: a meta-analysis

The prognostic role of epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinoma (HNSCC) remains controversial. The goal of this study was to summarize existing evidence regarding whether EGFR overexpression is a prognostic factor in HNSCC. Relevant studies were identified using Pubmed, Ovid, and Web of Science databases. A meta-analysis was conducted on the prognostic value of EGFR expression for overall survival (OS) and disease-free survival (DFS). Thirty-seven studies were included. Primary analysis indicated that EGFR overexpression was associated with reduced OS (hazard ratio [HR]: 1.694, 95% confidence interval [CI]: 1.432–2.004). DFS, on the other hand, was not associated with EGFR expression after adjusting for publication bias (HR: 1.084, 95% CI: 0.910–1.290). Subgroup analysis gave a statistically significant pooled HR for OS in laryngeal carcinoma (HR: 2.519, 95% CI: 1.615–3.928) and in oropharyngeal carcinoma (HR: 2.078, 95% CI: 1.605–2.690). The pooled HR was statistically significant for DFS with respect to oropharyngeal carcinoma (HR: 1.055, 95% CI: 1.020–1.092), but not laryngeal carcinoma (HR: 1.750, 95% CI: 0.911–3.360). When dividing studies based on the immunohistochemistry (IHC) scoring system, only the group that evaluated EGFR expression according to the intensity and extent of staining showed no between-study heterogeneity for both OS and DFS. Overall, EGFR overexpression was associated with shortened OS, but not DFS. Future studies are needed that stratify patients by specific tumor sites. Furthermore, when estimating protein level by the IHC method, it is advisable to consider both intensity and extent of staining.

Serum prognostic biomarkers in head and neck cancer patients

OBJECTIVES/HYPOTHESIS

A reliable estimate of survival is important as it may impact treatment choice. The objective of this study is to identify serum autoantibody biomarkers that can be used to improve prognostication for patients affected with head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

Prospective cohort study.

METHODS

A panel of 130 serum biomarkers, previously selected for cancer detection using microarray-based serological profiling and specialized bioinformatics, were evaluated for their potential as prognostic biomarkers in a cohort of 119 HNSCC patients followed for up to 12.7 years. A biomarker was considered positive if its reactivity to the particular patient's serum was greater than one standard deviation above the mean reactivity to sera from the other 118 patients, using a leave-one-out cross-validation model. Survival curves were estimated according to the Kaplan-Meier method, and statistically significant differences in survival were examined using the log rank test. Independent prognostic biomarkers were identified following analysis using multivariate Cox proportional hazards models.

RESULTS

Poor overall survival was associated with African Americans (hazard ratio [HR] for death = 2.61; 95% confidence interval [CI]: 1.58-4.33; P = .000), advanced stage (HR = 2.79; 95% CI: 1.40-5.57; P = .004), and recurrent disease (HR = 6.66; 95% CI: 2.54-17.44; P = .000). On multivariable Cox analysis adjusted for covariates (race and stage), six of the 130 markers evaluated were found to be independent prognosticators of overall survival.

CONCLUSIONS

The results shown here are promising and demonstrate the potential use of serum biomarkers for prognostication in HNSCC patients. Further clinical trials to include larger samples of patients across multiple centers may be warranted.

Molecular predictors of locoregional and distant metastases in oropharyngeal squamous cell carcinoma

Background

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing due to fundamental changes in oncogenesis related to effects of the human papilomavirus (HPV). Virally-mediated tumours behave and respond to treatment differently than their classic, carcinogenically-mediated counterparts despite similar stage and grade of disease. This difference in behaviour has lead to investigation of etiologies of OPSCC at the molecular level.

Molecular biomarkers offer potential insight into the behaviour of OPSCC. Identifying a subset of patients that are more likely to have recurrence and distant metastasis is valuable for prognostication and treatment planning. There is limited information regarding the profiles of these biomarkers in locoregional and distant metastases in OPSCC.

Objective

This study was designed to identify biomarker profiles predictive of locoregional and distant metastases and recurrence in OPSCC.

Methods

Cross-sectional study of a prospectively-collected oropharyngeal tumour database was undertaken. All patients with OPSCC presenting to the University of Alberta Hospital from 2002-2009 were included in the study. Data collection from the Alberta Cancer Registry, including demographics, nodal status, distant metastases, treatment, recurrence, and survival, was undertaken. Tissue micro-arrays (TMAs) were constructed for each tumour specimen using triplicate cores (0.6mm) of formalin-fixed, paraffin-embedded (FFPE) pre-treatment tumour tissue. TMAs were processed using immunohistochemistry for p16, EGFR, Ki67, p53, and Bcl-XL. Positivity for each biomarker was determined using quantified AQUAnalysis ® scores on histoplots. Multivariate statistics were utilized to assess the relationship between each biomarker and locoregional and distant metastases, as well as recurrence-free survival (RFS).

Results

High expression of p16 (p=0.000) and Bcl-XL (p=0.039) independently demonstrated a significant association with nodal disease at presentation. Kaplan-Meier analysis demonstrated improved RFS in patients with high p16 and decreased RFS in patients with high p53 expression. Cox regression analysis supported p16 as an independent prognosticator for improved RFS. p53 demonstrated an association with recurrence, but when compared to p16 status, nodal status, and staging, was not an independent predictor of recurrence.

Conclusions

Biomarker profiling using p16, Bcl-xL, and p53 may be useful in prognostication and treatment planning in patients with OPSCC.

Prognostic biomarkers of survival in oropharyngeal squamous cell carcinoma: systematic review and meta-analysis

BACKGROUND

Human papillomavirus (HPV) positivity improves prognosis in patients with oropharyngeal squamous cell carcinoma (OPSCC). Combining HPV status with other biomarkers may improve its prognostic power.

METHODS

The approach was a literature search for longitudinal studies of biomarkers in OPSCC, with systematic review and meta-analysis.

RESULTS

In all, 3130 articles were identified; 32 satisfied the inclusion and exclusion criteria. On meta-analysis, there was a significant overall survival (OS) benefit for patients with HPV positive and p16 positive tumors. There was some evidence of improved OS of OPSCC patients with raised bcl2; amplification of 11q3 and loss of 16q genes; and low c-met, ki67, IMD, PLK, FHIT, nuclear surviving, or nuclear cyclin D1. However, none of these was suitable for meta-analysis.

CONCLUSION

Survival from OPSCC is associated with several biomarkers, which constitute potential targets for research into improving the prognostic power of HPV in OPSCC. Larger trials are needed, with standardization of cut-points and adherence to consensus reporting guidelines.

A bone-seeking clone exhibits different biological properties from the ACHN parental human renal cell carcinoma in vivo and in vitro

Metastatic bone disease caused by renal cell carcinoma (RCC) occurs frequently. Very little is currently known about the mechanism of preferential metastasis of RCC to bone. We hypothesize that RCCs that develop bone metastases have the capacity to facilitate their colonization in bone. To examine this hypothesis, we established bone-seeking (ACHN-BO) clones of the human RCC cell line ACHN by repeated four passages in nude mice and in vitro of metastatic cells obtained from bone. These clones were examined for distinguishing biological characteristics and compared with the ACHN parental cells (ACHN-P) in vivo and in vitro. Our results showed that the ACHN-BO cell line could be successfully obtained by in vivo selection through the lateral tail vein. This approach results in the development of multiple osteolytic lesions in the distal femora and proximal tibiae within four weeks after inoculation, with a success rate of 85-100% and no additional comorbidity. ACHN-P cells developed metastases in lung, bone, brain, ovary and adrenal glands. Conversely, ACHN-BO cells exclusively metastasized to bones with larger osteolytic lesions. Compared with the ACHN-P cell line, the proliferation ability in ACHN-BO6 was increased by 9.68 and 6.42%, respectively (P<0.05), while the apoptotic ratio decreased significantly (P<0.05) and cells were blocked in the S phase with suppressed migration and invasion capacities. The ACHN-BO₆ cell line produced greater amounts of the pro-angiogenic factors VEGF and TGF-β than ACHN-P. Our data suggest that these phenotypic changes allow RCC cells to promote osteoclastic bone resorption, survive and proliferate in bone, which consequently leads to the establishment of bone metastases. This model provides a reliable reproduction of the clinical situation and, therefore, is suitable for designing and evaluating more effective treatments for RCC bone metastasis.

EGFR, p16, HPV Titer, Bcl-xL and p53, sex, and smoking as indicators of response to therapy and survival in oropharyngeal cancer

PURPOSE

To prospectively identify markers of response to therapy and outcome in an organ-sparing trial for advanced oropharyngeal cancer.

PATIENTS AND METHODS

Pretreatment biopsies were examined for expression of epidermal growth factor receptor (EGFR), p16, Bcl-xL, and p53 as well as for p53 mutation. These markers were assessed for association with high-risk human papillomavirus (HPV), response to therapy, and survival. Patient variables included smoking history, sex, age, primary site, tumor stage, and nodal status.

RESULTS

EGFR expression was inversely associated with response to induction chemotherapy (IC) (P = .01), chemotherapy/radiotherapy (CRT; P = .055), overall survival (OS; P = .001), and disease-specific survival (DSS; P = .002) and was directly associated with current smoking (P = .04), female sex (P = .053), and lower HPV titer (P = .03). HPV titer was significantly associated with p16 expression (P < .0001); p16 was significantly associated with response to IC (P = .008), CRT (P = .009), OS (P = .001), and DSS (P = .003). As combined markers, lower HPV titer and high EGFR expression were associated with worse OS (rho(EGFR) = 0.008; rho(HPV) = 0.03) and DSS (rho(EGFR) = 0.01; rho(HPV) = 0.016). In 36 of 42 biopsies, p53 was wild-type, and only one HPV-positive tumor had mutant p53. The combination of low p53 and high Bcl-xL expression was associated with poor OS (P = .005) and DSS (P = .002).

CONCLUSION

Low EGFR and high p16 (or higher HPV titer) expression are markers of good response to organ-sparing therapy and outcome, whereas high EGFR expression, combined low p53/high Bcl-xL expression, female sex, and smoking are associated with a poor outcome. Smoking cessation and strategies to target EGFR and Bcl-xL are important adjuncts to the treatment of oropharyngeal cancer.

Epidermal Growth Factor Receptor Status Predicts Local Response to Radical Radiotherapy in Muscle-invasive Bladder Cancer

AIMS

Epidermal growth factor receptor (EGFR) is expressed by over 70% of muscle-invasive bladder tumours and is associated with diminished overall survival. In model tumour systems, ionising radiation has been shown to activate EGFR, leading to cellular proliferation and is therefore a possible mechanism of underlying radioresistance. We carried out an immunohistochemical study relating the clinical outcome of patients receiving radical radiotherapy for muscle-invasive bladder cancer to tumour EGFR status.

MATERIALS AND METHODS

Archived paraffin-embedded tumours from 110 consecutive patients receiving radical radiotherapy for muscle-invasive bladder cancer between 1991 and 1997 were immunohistochemically stained for EGFR. Data were collected concerning the tumour stage and grade, the presence of ureteric obstruction, the response to radiotherapy at 3 months, local recurrence rates, metastatic spread and survival. Multivariate analysis of potential independent prognostic factors of impaired bladder cancer-specific survival was carried out using Cox's regression.

RESULTS

Of 110 tumours, 79 (72%) stained positively for EGFR. Of 87 patients undergoing the 3-month check cystoscopy, 60 (69%) had a positive response to radiotherapy. A positive response to radiotherapy correlated significantly with a negative EGFR status (chi(2) test, P = 0.05). Kaplan-Meier survival analysis revealed a trend towards improved bladder cancer-specific survival in EGFR-negative patients (Log-rank, P = 0.10). A lack of response to radiotherapy at 3 months, local recurrence, metastatic spread and the presence of ureteric obstruction were all independent prognostic factors for diminished bladder cancer-specific survival (Cox's regression: P = 0.009, P = 0.001, P = 0.04 and P = 0.005, respectively).

CONCLUSIONS

EGFR status predicts the local response to radiotherapy but does not provide prognostic utility in relation to overall or bladder cancer-specific survival. As EGFR status seems to be linked to the initial response to radiotherapy, its inhibition may be a means of enhancing the radio-responsiveness of these poor prognosis tumours. Colquhoun, A. J.

Expression of structural proteins and angiogenic factors in normal arterial and unruptured and ruptured aneurysm walls

OBJECTIVE

To identify differences in the expression of certain structural proteins and angiogenic growth factors in vessel tissues that represent different phases of the process of intracranial aneurysm formation and rupture: normal vessel wall, intact (unruptured) aneurysm wall, and ruptured vessel wall.

METHODS

The novel study design involved 10 pairs of specimens (ruptured and unruptured aneurysm wall) obtained perioperatively during clipping operations in 10 patients with multiple aneurysms. All surgeries were performed within 5 days of subarachnoid hemorrhage. As controls, five circle of Willis specimens were obtained from five cadavers. Sections of each of the 25 specimens were separately immunostained for five structural proteins (collagen Types III and IV, alpha-smooth muscle actin, fibronectin, and laminin) and three angiogenic factors (vascular endothelial growth factor, basic fibroblast growth factor, and transforming growth factor-alpha). Levels of expression for each protein and factor were graded, and the average grades for each tissue group were recorded and compared.

RESULTS

Among the structural proteins studied, fibronectin specifically is densely expressed in ruptured aneurysms, which is graded as 2.0. However, its expression is less prominent both in nonaneurysmal vessel wall (Grade 1.0) and unruptured aneurysm vessel wall (Grade 1.1). Contrary to fibronectin, laminin is more intensely and regularly expressed in normal vessel wall (Grade 2.7) than in ruptured (Grade 1.1) and unruptured (Grade 1.0) aneurysmal specimens. Among the angiogenic growth factors studied, transforming growth factor-alpha shows a peculiar grading of staining, different from the other two angiogenic factors examined, so that it is more highly expressed in normal circle of Willis specimens (Grade 2.1) than in unruptured and ruptured aneurysm walls, graded as 0.5 and 0.6, respectively.

CONCLUSION

Normal vessel wall, unruptured aneurysm wall, and ruptured aneurysm wall exhibit different levels and patterns of expression for the structural proteins and regulator growth factors investigated. If one accepts the premise that immunohistochemical study has its inherent methodological problems, these results suggest that the biological mediators of aneurysm formation in a vessel wall differ from those of the biological mediators of aneurysm rupture. There was a novel finding related to fibronectin and laminin: the results indicated that a rise in the fibronectin-to-laminin ratio in an unruptured aneurysm wall may contribute to rupture. A drop in transforming growth factor-alpha expression in a vessel wall may also contribute to aneurysm formation.

Microvessel density and expression of vascular endothelial growth factor, basic fibroblast growth factor, and platelet-derived endothelial growth factor in oral squamous cell carcinomas

Angiogenesis, the growth of capillary vessels, plays an important role in the metabolic functions of malignant tissues. Tumor growth and malignant transformation are considered to be dominated by uncontrolled angiogenesis. To understand the mechanism of increased vascularity associated with malignant tissues, we immunohistochemically evaluated microvessel density (MVD) and the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and platelet-derived endothelial growth factor (PDGF) in oral cancers. Microvessel density did not differ significantly between normal oral mucosa and epithelial dysplasia, but was significantly increased in tumor tissues. Expression of angiogenic factors was not found in normal oral mucosa, but increased in association with increasing vascularity in OSCC tissue. In tumor tissue, angiogenic factor expression correlated with MVD. MVD in OSCC was related to T stage, tumor differentiation, and stage of invasion. VEGF expression also correlated with tumor differentiation and the stage of invasion. These findings suggest that VEGF might play an important role in tumor angiogenesis of OSCC.