VEGF-C expression in squamous cell carcinoma and adenocarcinoma of the esophagus

BACKGROUND

Vascular endothelial growth factor C (VEGF-C) is the only factor known to cause lymphangiogenesis. In esophageal cancer the histologic tumor type and lymph node metastasis are independent predictors of recurrence and poor outcome. To evaluate the rule of VEGF-C expression in esophageal cancer, we investigated 113 specimens, 59 squamous cell and 54 adenocarcinomas of the esophagus.

METHODS

The expression of VEGF-C was evaluated using immunohistochemistry (IHC) on 59 paraffin-embedded archival specimens from patients with squamous cell esophageal carcinomas and 54 paraffin-embedded archival specimens of patients with esophageal adenocarcinomas arising in Barrett's mucosa. All patients had a complete tumor resection. A complete and updated follow-up was available for all patients.

RESULTS

The expression of VEGF-C was significantly different between the two histological types of esophageal tumors. Patients with squamous cell carcinoma and lymph node metastases had a significantly higher VEGF-C expression (P < 0.01). In patients with adenocarcinoma of the esophagus there was no correlation between VEGF-C expression and clinicopathological parameters. High VEGF-C expression tended to be correlated with poor survival in squamous cell cancer but not in adenocarcinoma of the esophagus.

CONCLUSIONS

The present study indicates that VEGF-C may play a role in tumor progression via lymphangiogenesis in squamous cell carcinoma of the esophagus. This seems not to be true for the adenocarcinoma of the esophagus. These data could help with the understanding of the different onset and characteristics of lymph node metastasis in squamous cell carcinoma and adenocarcinoma of the esophagus.

Lymphangiogenesis in myocardial remodelling after infarction

Ishikawa Y, Akishima-Fukasawa Y, Ito K, Akasaka Y, Tanaka M, Shimokawa R, Kimura-Matsumoto M, Morita H, Sato S, Kamata I & Ishii T (2007) Histopathology51, 345–353

Lymphangiogenesis in myocardial remodelling after infarction

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.

Correlations between cyclooxygenase-2 expression and angiogenic factors in primary tumors and liver metastases in colorectal cancer

BACKGROUND

Angiogenesis is required for growth and metastasis of colorectal cancer (CRC), and several positive regulators of tumor angiogenesis have been identified. Cyclooxygenase-2 (COX-2), known to be elevated in several human cancers, regulates angiogenesis by inducing angiogenic factors. The aim of this study was to clarify the levels and evaluate the relationships of COX-2, vascular endothelial growth factor A and C, thymidine phosphorylase (TP) and microvascular density (MVD) in paired tissue specimens between primary CRC and corresponding metastatic liver cancer.

METHODS

Tissue samples from pairs of primary tumors and corresponding metastatic liver tumors from 44 patients with CRC were immunohistochemically evaluated for COX-2, VEGF-A, VEGF-C, TP and MVD.

RESULTS

The primary and corresponding metastatic liver tumors tended to show concordant immunoreactivity for COX-2 (P = 0.005, rs = 0.428), VEGF-A (P = 0.039, rs = 0.314), TP (P = 0.005, rs = 0.422) and MVD (P = 0.046, rs = 0.304) by Spearman rank test. The rate of COX-2 immunoreactivity was higher in liver metastases than in primary tumors (P = 0.002), while the rate of VEGF-A was higher in primary tumors than in liver metastases (P = 0.0004). The incidence of TP immunoreactivity and the level of MVD did not differ between primary and metastatic liver tumors (P = 0.247; P = 0.229). Significant correlations were found between COX-2 immunoreactivity and VEGF-A immunoreactivity in metastatic liver tumors (P = 0.033) as well as in primary tumors (P = 0.008).

CONCLUSION

The positive correlations between COX-2, VEGF-A, TP and MVD in primary CRC and liver metastasis as demonstrated here will help to predict the angiogenic activity of liver metastasis by analyzing primary tumors, allowing for individualized cancer treatment options.

The importance of angiogenesis markers in the outcome of patients with diffuse large B cell lymphoma: a retrospective study of 97 patients

PURPOSE

The role of angiogenesis has been extensively evaluated in solid tumors and more recently in hematologic malignancies. Several surrogate markers of angiogenesis including tumor VEGF, VEGF receptors, and microvessel density have correlated with outcome in some lymphoma studies. This is a single institution retrospective study evaluating the role of angiogenesis markers in the clinical outcome of patients with diffuse large B cell lymphoma (DLBCL).

PATIENTS AND METHODS

A total of 97 patients with DLBCL diagnosed and managed at Indiana University between 1993 and 2001 were included. Archived tumor samples were stained for VEGF-A, VEGF-C, VEGF-R1, and CD31 and graded as negative or positive (1+, 2+, 3+). The relationship between the expression of these markers and the international prognostic variables as well as the progression free survival (PFS) and the overall survival (OS) was evaluated.

RESULTS

VEGF-A, VEGF-C, VEGF-R1 were expressed in 77, 98, and 18% of tumors, respectively. VEGF-A negative patients had an improved OS compared to VEGF-A (1+) (P = 0.0502). VEGF-C correlated with both LDH (r = 0.28, P = 0.0502) and IPI score (r = 0.25, P = 0.013). VEGF-R1 negative patients had a superior survival compared to those with VEGF-R1 (2+) (P = 0.0154).

CONCLUSIONS

The presence of tumor associated angiogenesis may alter the outcome of patients with DLBCL and could be a prognostic factor. Further clinical studies are needed to correlate the degree of angiogenesis with response to anti-angiogenesis agents.

Significance of lymphatic invasion and proliferation on regional lymph node metastasis in renal cell carcinoma

We studied the associations of lymphatic invasion and lymphatic vessel density around tumors with lymph node (LN) status in renal cell carcinoma (RCC) by immunohistochemical analysis using D2-40 antibody as a lymphatic marker. Surgically removed specimens from 76 cases with RCC, including 16 cases with LN metastasis, were used. Lymphatic vessel density around the tumor increased compared with normal kidneys but was not significant by LN status. Tumor size, tumor cell types, patterns of tumor growth, nuclear grade of tumor cells, venous invasion, lymphatic invasion, and primary tumor stage were predictive factors for LN metastasis. Based on multivariate regression analysis, only lymphatic invasion was an independent risk factor for LN metastasis. The immunohistochemical detection of lymphatics was useful for identifying the lymphatic invasion of RCC, and the presence of lymphatic invasion around RCC was an independent predictive factor for LN metastasis.

[Angiogenic factors and their relation to stage, lymph-node micrometastases and prognosis in patients operated on for gastric cancer]

The aim of the present study was to investigate the expression of a number of angiogenic factors such as VEGF, VEGF-C, TGF-alpha and apoptosis in an attempt to relate these biological markers to TNM staging, lymph-node status and prognosis. Angiogenic factors and apoptosis were studied immunohistochemically in 72 gastric cancer cases. The search for micrometastases was performed with an immunohistochemical technique in 20 NO cases. Apoptosis determination was assessed with the TUNEL assay. The chi2 test according to Pearson was used for statistical analysis. The apoptotic index was related to both stage and prognosis: high expression cases showed an earlier stage (p < 0.02) and a better prognosis (p < 0.05). The determination of high neovessel density was related to poorer 5-year survival (p < 0.05). Only the expression of VEGF-C correlated inversely with prognosis (p < 0.05). The presence of micrometastases was unrelated to any of the biological markers studied. Our results partly confirm those reported in the literature. The present study revealed a number of biological markers that may be helpful for identifying particular subgroups of patients. More investigation with similar techniques in large prospective series is needed as a support to clinical practice.

Regional difference in intratumoral lymphangiogenesis of oral squamous cell carcinomas evaluated by immunohistochemistry using D2-40 and podoplanin antibody: an analysis in comparison with angiogenesis

BACKGROUND

Whether tumor cells induce lymphangiogenesis intratumorally or permeate pre-existing lymphatic vessels in the peritumoral area still remains unclear. In this study, we investigated in detail the intratumoral lymphangiogenesis of oral squamous cell carcinomas (SCC) in comparison with tumor angiogenesis.

METHODS

Immunohistochemistry with D2-40, podoplanin antibody, and CD34 antibody were used to evaluate the lymphatic vessel density (LVD) and blood microvessel density (MVD). Vascular endothelial growth factor (VEGF) and VEGF-C expressions of oral SCC were also assessed by immunohistochemistry.

RESULTS

LVD significantly increased in the superficial area of tumor tissue compared with normal mucosa, whereas it decreased in the deep area of intratumoral tissue near the invasion front, in sharp contrast to MVD, which significantly increased throughout tumor tissue. Consistent with the decreased intratumoral LVD and increased intratumoral MVD, VEGF-C expression of tumor cells was down-regulated in the deep area of tumor tissue, while VEGF expression of tumor cells was up-regulated throughout the tumor tissue.

CONCLUSIONS

Lymphangiogenesis in oral SCC varies depending on the region within the tumor tissue. It is not induced in the genuine tumor stroma near the invasion front, probably due to the down-regulation of VEGF-C expression of tumor cells, which is different from VEGF-mediated induction of intratumoral angiogenesis.

Predictive value of vascular endothelial growth factor-C expression for local recurrence of rectal carcinoma

Vascular endothelial growth factor-C (VEGF-C) is considered to be a specific factor promoting lymphangiogenesis. There have been reports of a positive correlation between local recurrence of rectal carcinoma and lymphatic invasion by the tumor. The aim of this study was to determine the clinical significance of VEGF-C expression for identifying lymphangiogenesis as a predictor of the local recurrence of rectal carcinoma. One hundred surgical specimens of rectal carcinoma from patients with (n=26) or without (n=74) local recurrence were studied. VEGF-C protein expression was assessed immunohistochemically. The correlations between VEGF-C expression, various clinicopathologic factors, the microscopic lymphatic vessel density (MLVD), and lymphatic invasion were studied. The MLVD (determined by immunohistostaining for D2-40) was significantly higher in VEGF-C positive tumors than VEGF-C negative tumors. VEGF-C positivity was only correlated with lymphatic involvement. Moreover, multivariate analysis showed that VEGF-C protein expression was an independent risk factor for the local recurrence of rectal carcinoma, and patients with VEGF-C positive tumors had a significantly worse prognosis than those with VEGF-C negative tumors. Expression of VEGF-C may be a good predictor of the local recurrence of rectal carcinoma and may also be a useful prognostic indicator.

Lymphatic and blood vessel morphometry in invasive breast carcinomas: relation with proliferation and VEGF-C and -D proteins expression

INTRODUCTION

The aim of the present study was to investigate the distribution of both lymphatics and blood microvessels in invasive breast carcinomas and the clinicopathological and prognostic significance of their density and size related parameters as well as their correlation with the proliferative potential of the tumor and VEGF-C and -D expression.

METHODS

Both single and double immunohistochemistry were applied on a series of 146 paraffin-embedded breast tissue specimens to detect VEGF-C and -D as well as lymphatics and blood microvessels, respectively. Computer-assisted morphometry was performed to evaluate the blood and lymphatic vessel density (BVD and LVD respectively) as well as various vascular size related parameters.

RESULTS

Lymphatics were detected within the stroma at the tumor border, while blood vessels were located in both the interior of the tumor mass and peritumor stroma. BV major axis, minor axis and perimeter inversely correlated with ER (p=0.011, p=0.023 and p=0.008 respectively), while LV major axis, minor axis and the perimeter inversely correlated with tumor nuclear grade (p=0.045, p=0.037 and p=0.032 respectively) and topoisomerase IIalpha (p=0.015, p=0.024 and p=0.045 respectively). The same LV parameters were found to positively correlate with cancerous VEGF-C (p<0.0001, p=0.092 and p=0.012 respectively) and VEGF-D in the stromal fibroblasts surrounding neoplastic cells (p=0.011, p=0.041 and p=0.026 respectively). High BVD exerted an unfavorable impact on both disease-free (p=0.021) and overall survival (p=0.031) of the patients. High LVD correlated with poor disease-free and overall survival only in the subgroup of patients with ER-negative tumors (p=0.056 and p=0.0312 respectively).

CONCLUSION

These findings, for the first time, correlate lymphatic size with tumors of limited proliferative potential and higher nuclear differentiation. Moreover, they suggest that VEGF-C and -D expression influence lymphatic size rather than being involved in the increase of lymphatic vessel number.

Increased apoptosis and angiogenesis in gastric low-grade mucosa-associated lymphoid tissue-type lymphoma by Helicobacter heilmannii infection in C57/BL6 mice

Helicobacter heilmannii has been reported to cause gastric low-grade mucosa-associated lymphoid tissue-type (MALT) lymphoma, but its precise pathophysiological mechanism remains to be clarified. We recently established a model of gastric B-cell MALT lymphoma in C57BL/6 mice by means of peroral infection of H. heilmannii primarily obtained from cynomolgus monkeys. Using this model, macroscopic, immunohistochemical, and electron microscopic observations of MALT lymphomas were carried out in order to examine the development of apoptosis and angiogenesis. Enhancement of the microvascular network and an increase in vascular endothelial growth factor-A were detected in the central region of the MALT lymphoma tissue in the infected mouse stomach, while vascular endothelial growth factor-C was detected at the margins of the MALT lymphomas. In addition, many H. heilmannii-invaded parietal cells showed caspase-3 immunoreactivity in the fundic mucosal tissue surrounding the MALT lymphoma. In conclusion, in H. heilmannii-induced MALT lymphoma, enhanced immunoreactivity of vascular endothelial growth factor-A and factor-C was observed in areas encircled by increased parietal cell apoptosis, which indicates the pathophysiological relevance of both angiogenesis and apoptosis in MALT lymphoma formation.

Absence of lymphangiogenesis in ductal breast cancer at the primary tumor site

Solid evidence for a relationship between lymphangiogenesis and prognosis in human breast cancer is still lacking. Evidence for ongoing lymphangiogenesis in breast cancer is only provided by animal studies. In the present study we investigated lymphatic vessel density as well as the expression level of the lymphangiogenic factors VEGF-C and -D in a series of 121 ductal breast cancer tissues using immunohistochemical stainings. We found that in the primary tumors the lymphatic vessel density, as well as the expression of both VEGF-C and -D, did not relate to grade, tumor stage, progression or patient survival. Furthermore, in tumors in which lymphatic vessels were present, a Ki-67/podoplanin double staining indicated the absence of proliferating lymphatic endothelial cells. In contrast, we did find a correlation between intratumoral lymphatic vessel density inside the lymph node metastases and patient survival. Another parameter that revealed prognostic value was the presence of tumor cells within the lymphatic vessels. This parameter did predict survival in patients with an age below 63 only. Interestingly, expression of VEGF-D was found to be related to the presence of intralymphatic tumor cells.

Histopathological and lymphangiogenic parameters in relation to lymph node metastasis in early stage oral squamous cell carcinoma

PURPOSE

Lymph node metastasis from oral squamous cell carcinoma (SCC) correlates with a poor prognosis. Therefore, accurate assessment of lymph node status is crucial in treatment planning. Furthermore, prediction of delayed neck metastasis (DNM), especially in early stage tumors with a clinically negative (N0) neck, will determine the need for neck dissection or irradiation. In this study, we assess various clinical, histopathological and lymphangiogenic parameters in early stage oral SCC and their association with DNM.

MATERIALS AND METHODS

Clinical, histological, and immunohistochemical analyses were undertaken for 29 patients with T1N0M0 or T2N0M0 oral SCC affecting the tongue or floor of mouth and correlated with the development of DNM.

RESULTS

Tumor thickness, nuclear pleomorphism, pattern of invasion, and immunohistochemical expression of the lymphangiogenesis-associated molecules VEGFR-3 and VEGF-C were associated with DNM.

CONCLUSIONS

Analysis of these parameters may help to identify patients who would benefit from a neck dissection or irradiation by predicting the likelihood of lymph node metastasis.

Lymphangiogenesis of normal endometrium and endometrial adenocarcinoma

BACKGROUND

Information about lymphatics and lymphangiogenesis in the human endometrium is limited. We investigated the distribution of endometrial lymphatic vessels during the normal menstrual cycle and in association with endometrial adenocarcinoma and investigated the expression of lymphangiogenic growth factors, vascular endothelial growth factor (VEGF)-C, VEGF-D and VEGF receptor-3 (VEGF-R3).

METHODS AND RESULTS

Full thickness uterine samples (n = 23 proliferative; n = 23 secretory) and endometrial adenocarcinoma samples (n = 7 grade I; n = 10 grade III) were collected for the study and analysed by immunohistochemistry and western blotting. Lymphatic vessels of the functionalis were significantly reduced compared with basalis (P = 0.001) across the menstrual cycle with lymphatics of the basalis sometimes intimately associated with spiral arterioles. Lymphatic vessels of endometrial adenocarcinomas were located intra-tumoural and peri-tumoural with significant increases in the peri-tumoural lymphatic vessels compared with normal basalis (P = 0.02). Interestingly, high-grade adenocarcinoma vessels containing tumour emboli demonstrated a mixed blood/lymphatic endothelial cell phenotype. VEGF-C and VEGF-D were immunolocalized in glandular epithelium and some stromal cells with the staining intensity of this localization increasing in endometrial adenocarcinoma. Protein analysis identified VEGF-C (58, 41, 31 and 21 kD) and VEGF-D (56, 41, 31 and 21 kD) and VEGF-R3 (148 and 65 kD) peptides in normal endometrium, with significant increases in several of these peptides for VEGF-C and VEGF-D and no changes in protein expression for VEGF-R3 in endometrial adenocarcinoma.

CONCLUSION

Endometrial lymphatics are significantly reduced in the functionalis, and increases in endometrial adenocarcinoma peri-tumoural lymphatics are associated with increases in VEGF-C and VEGF-D peptides.

Quantitative analysis of lymphangiogenic markers in human gastroenteric tumor

BACKGROUND

Lymphatic spread of gastroenteric tumor cells to regional lymph nodes is one of the early events in metastatic cancers and is often associated with distant metastatic spread and poor prognosis. Expression levels of newly described lymphatic endothelial markers, LYVE-1, VEGF-C, VEGF-D and the VEGF receptors VEGFR-3 were assessed in our study.

METHODS

Paired (tumor and corresponding normal tissue) samples were obtained. The expression level of each factor was determined using RT-PCR and quantified by using a real-time quantitative PCR (RT-QPCR) technique, with respective cloned cDNA plasmids as internal standards.

RESULTS

The expression of VEGF-C and lymphatic endothelial marker VEGFR-3 was significantly greater in patients with lymph node metastasis than in those without metastasis, but no different expression level of VEGF-D and LYVE-1 was detected in both groups of patients. Lymphatic vessel density (LVD), which was assessed by immunohistochemistry for LYVE-1, was correlated with lymphangiogenesis factors and lymph node metastasis. Expression of VEGF-C and VEGFR-3 was significantly associated with higher peritumoral LVD than normal group, and LVD was found greater in the node-positive group than in the node-negative group.

CONCLUSIONS

These results indicate that quantitative analysis of lymphangiogenic marker VEGF-C and VEGFR-3 in gastroenteric specimens may be useful in predicting metastasis of gastroenteric cancer to regional lymph nodes, but the role of LYVE-1 in predicting metastasis of gastroenteric cancer requires further analysis.

Invasive micropapillary carcinoma of the breast: association of pathologic features with lymph node metastasis

Invasive micropapillary carcinoma (IMPC) of the breast is characterized by a high incidence of axillary lymph node metastasis. To investigate the relationship between pathologic features and lymph node metastasis, 51 cases of breast carcinoma with IMPC components were studied. Immunohistochemical analysis for vascular endothelial growth factor (VEGF)-C and VEGF receptor (VEGFR)-3 was performed, and lymphatic vessel density was measured. The main findings included a significantly increased number of positive lymph nodes and/or an increased rate of lymph node metastasis in IMPC with a higher histologic grade, prominent stromal infiltration of lymphocytes, and higher VEGF-C expression and lymphatic vessel density. The percentage of IMPC component in the tumor was not associated with the incidence of lymph node metastasis. The results suggest that the histologic grade, lymphatic vessel density, and lymphocyte infiltration of IMPC are the key factors that influence lymph node metastasis. Further studies are required to elucidate the mechanisms underlying the lymphotropism of this distinct variant of breast carcinoma.

Mediastinal lymphangiomatosis coexisting with occult thymic carcinoma

Mediastinal lymphangiomatosis in a 70-year-old woman was diagnosed on a medical checkup. The tumor was resistant to sclerotherapy with OK432 or bleomycin. The patient continued on a downhill course and died approximately 3 years after the initial diagnosis. Autopsy revealed a large tumor mass occupying the anterior mediastinum and firmly adhered to the pericardium and the pleura. The tumor consisted of two intermingled lesions: dilated vessels lined with D2-40-positive lymphatic endothelium and CD5-positive atypical cell nests with focal keratinization. The former was diagnosed as lymphangiomatosis and the latter as thymic squamous cell carcinoma. Vascular endothelial growth factor (VEGF)-C, a growth factor for lymphatic endothelial cells, was expressed by the carcinoma, and VEGF-C receptor was expressed by the endothelium of lymphangiomatosis. These findings suggested that VEGF-C derived from the thymic carcinoma induced the lymphangiomatosis lesion in a paracrine manner.

The regulation of vascular endothelial growth factors (VEGF-A, -C, and -D) expression in the retinal pigment epithelium

The vascular endothelial growth factor (VEGF) family plays an essential role in vascular development, angiogenesis and lymphangiogenesis. VEGF-A is a key regulator of endothelial cell functions and VEGF-C and VEGF-D are known to stimulate both angiogenesis and lymphangiogenesis. In a surgically removed subretinal vascular membrane of an age-related macular degeneration (AMD) patient, both VEGF-C and VEGF-D were confirmed, in addition to VEGF-A, to be markedly positive in the retinal pigment epithelium (RPE). There is no lymph vessel in ocular tissue, so it is possible that VEGF-C and VEGF-D expression in the RPE play some role in ocular angiogenesis, as well as VEGF-A. Next, we assessed the transition of VEGF-A, -C, and -D expression on several conditions, in human RPE. Hypoxia proverbially induced VEGF-A mRNA expression, meanwhile VEGF-C and VEGF-D mRNA expression was down-regulated. The Ca(2+) deprivation from culture medium strongly up-regulated VEGF-A and VEGF-D mRNA expression. Culture on plastic flasks precoated with poly-2-hydroxyethyl methacrylate up-regulated VEGF-D expression. Meanwhile, no significant change of VEGF-C mRNA expression was found in the blockade of cell-cell and/or cell-matrix adhesion. These findings suggest the possibility that VEGF-C and VEGF-D expression in RPE modify the ocular angiogenesis as angiogenic stimulators.

Intratumoral Lymphatic Vessels and VEGF-C Expression Are Predictive Factors of Lymph Node Relapse in T1-T4 N0 Laryngopharyngeal Squamous Cell Carcinoma

BACKGROUND

The presence of intratumoral lymphatic vessels (ILVs) and the expression of vascular endothelial growth factor-C (VEGF-C) in tumour cells have been studied as markers of lymphangiogenesis in order to evaluate their role in metastatic dissemination in laryngopharyngeal squamous cell carcinoma.

METHODS

A retrospective study was performed in 76 patients of N0 laryngopharyngeal carcinoma. with variable tumour size (T1-T4), histological grade, and location (supraglottic, glottic and hypopharyngeal). The presence of ILVs, as revealed by the expression of PA2.26 antigen and VEGF-C expression, were determined by immunohistochemistry (IHC). Low-grade and high-grade lymphangiogenesis were defined by qualitative and quantitative criteria.

RESULTS

Multivariate analysis revealed low-grade ILV and VEGF-C expression to be associated respectively with 30.3- and 16.2-fold higher probabilities of cervical lymph node relapse (P = 0.005 and P = 0.032) and with 16.2- and 8.44-fold shorter disease-free survival (P = 0.009 and P = 0.045).

CONCLUSIONS

Low-grade ILV and VEGF-C expression are independent predictive factors of cervical lymph node relapse and shortening of time to relapse in N0 laryngopharyngeal carcinoma.

Localisation of lymphatic vessels and vascular endothelial growth factors-C and -D in human and mouse skeletal muscle with immunohistochemistry

The present study was aimed to localise lymphatic vessels and their growth factors in human and mouse skeletal muscle with immunohistochemistry and specific antibodies (VEGFR-3, LYVE-1, VEGF-C and VEGF-D). The largest lymphatic vessels were found in perimysial connective tissue next to the arteries and veins, as has been shown earlier with electron microscopy. As a new finding, we also found small LYVE-1 positive vessels in the capillary bed between muscle fibres. These vessels were located next to CD31 positive blood capillaries and were of the same size, but fewer in number. In addition, we described the localisation of the two main lymphangiogenic growth factor proteins, vascular endothelial growth factor-C and -D. Both proteins were expressed in skeletal muscle at mRNA and protein levels. VEGF-D was located under the sarcolemma in some of the muscle fibres, in the endothelia of larger blood vessels and in fibroblasts. VEGF-C protein was localised to the nerves and muscle spindles, to fibroblasts and surrounding connective tissue, but was not found in muscle fibres or endothelial cells. Our results are the first to suggest the presence of lymphatic capillaries throughout the skeletal muscle, and to present the localisation of VEGF-C and -D in the muscles.

VEGF-C expressing tumor-associated macrophages in lymph node positive breast cancer: impact on lymphangiogenesis and survival

BACKGROUND

The ability of malignant tumors to metastasize presents a severe challenge in cancer treatment. Lymphatic vessels provide one of the main routes for tumor-metastasis on the way to regional lymph nodes. Increasing evidence suggests that inflammatory cells play an important role in tumor-associated angiogenesis and lymphangiogenesis. Recent data show that a specialized sub fraction of tumor-associated macrophages (TAMs) expressing the lymphoangiogenic growth factors vascular endothelial growth factor-C and -D (VEGF-C/D) at the tumor site, is related to lymphangiogenesis, lymphovascular invasion, and lymph node metastasis. Aim of this study was to clear the role of VEGF-C/D expressing TAMs in invasive breast cancer.

METHODS

One hundred-seven cases of lymph node positive invasive breast cancer were included into the study. Lymphatic microvessel density (LMVD), lymphovascular invasion (LVI), peritumoral inflammatory reaction (PI), and VEGF-C expression in tumors (VEGF-C(T)) and TAMs (VEGF-C(C)) were evaluated by immunohistochemistry and in situ hybridization.

RESULTS

Significant associations were seen between LMVD and LVI, LMVD and VEGF-C(T), and between VEGF-C(T) and VEGF-C(C). Further significant correlations were evaluated between VEGF-C(C)/VEGF-C(T) and PI as well as between PI and LVI. LVI remained an independent prognostic factor for disease-free survival and overall survival.

CONCLUSIONS

Our data provide evidence that the peritumoral inflammatory reaction and VEGF-C expressing TAMs may play an important role in tumor lymphangiogenesis and lymphovascular invasion in invasive breast cancer, implying new potential anti-tumor targets.

VEGF-C and COX-2 expression in papillary thyroid cancer

In papillary thyroid cancer (PTC), age appears to be the most important single prognostic factor. Another characteristic feature is the lack of association between survival and lymph node metastases. Earlier, we found that expression of cyclooxygenase-2 (COX-2) is higher in older PTC patients, in agreement with the finding that older patients have a worse prognosis. Recent findings suggest that COX-2 can up-regulate vascular endothelial growth factor-C (VEGF-C) expression. Here, we investigated whether expression of VEGF-C differs between young and older PTC patients and whether expression of VEGF-C and COX-2 are correlated. Our retrospective study comprised 106 PTC patients selected by age: those under 35 or over 55 at diagnosis. Paraffin-embedded tissue samples were analysed by immunohistochemistry for VEGF-C protein expression. Furthermore, we investigated by quantitative RT-PCR and enzyme immunoassay the relationship between VEGF-C and COX-2 expression in papillary thyroid cancer cells (NPA cells). VEGF-C expression was significantly increased with age. In the tumours from older lymph node-positive (N1) patients, VEGF-C expression was significantly higher than in the tumours from young N1 patients. Moreover, all patients who died of cancer or who developed distant metastases were old, and most tumours from these patients (4 of 5) expressed VEGF-C and had had nodal metastases at the time of primary operation. Immunohistochemically, expression of COX-2 and VEGF-C correlated strongly. In cell culture, this correlation was not so clear, because the COX-2 selective inhibitor, NS-398, did not reduce VEGF-C expression. However, as both COX-2 and VEGF-C were induced by the tumour promoter phorbol 12-myristate 13-acetate (PMA), the same factors may control them both.

Impact of lymph node micrometastasis in hilar bile duct carcinoma patients

AIM: To immunohistochemically examine micrometastasis and VEGF-C expression in hilar bile duct carcinoma (HBDC) and to evaluate the clinical significance of the results.

METHODS: A total of 361 regional lymph nodes from 25 patients with node-negative HBDC were immunostained with an antibody against cytokeratins 8 and 18 (CAM 5.2), and immunohistochemical staining of VEGF-C was performed in 34 primary resected tumors.

RESULTS: Lymph node micrometastasis was detected in 6 (24%) of the 25 patients and 10 (2.8%) of the 361 lymph nodes. Patients with micrometastasis showed significantly poorer survival rates than those without (P = 0.025). VEGF-C expression was positive in 17 (50%) of 34 HBDC, and significantly correlated with lymph node metastasis (P = 0.042) and microscopic venous invasion (P = 0.035).

CONCLUSIONS: It is suggested that immunohistochemically detected lymph node micrometastasis has an impact on the outcome of HBDC. VEGF-C expression is highly correlated with lymph node metastasis in HBDC and might therefore be a useful predictor.

Role of lymphangiogenesis and lymphangiogenic factors during pancreatic cancer progression and lymphatic spread

Treatment options for ductal adenocarcinoma of the pancreas are limited by early lymphatic spread, but the lymphatic vessels in pancreatic carcinoma have not been studied to date. Here, we present a histomorphological analysis of lymphatic vessels in pancreatic cancer resection specimens. Both intratumoral and peritumoral tissue were devoid of active lymphangiogenesis. Intratumoral lymphatics were frequently collapsed and non-functional, whereas peritumoral lymphatic vessels were enlarged, and numerous lymphatic vessels were seen in metastases. In addition, we screened pancreatic cancer tissue and pancreatic carcinoma cell lines for mRNA expression of the lymphangiogenic growth factor, VEGF-C; its receptor, VEGFR-3/flt4; and Prox1, a transcription factor essential for embryonic development of both lymphatic vessels and the pancreatic bud. VEGF-C was abundantly expressed in pancreatic cancer tissue and -cell lines and VEGFR-3/flt4 was expressed in cancer stromal cells. Prox1 was strongly expressed in the normal exocrine pancreas but significantly reduced in pancreatic cancer specimens from patients with short survival rates. Well-differentiated cell lines displayed higher levels of Prox1 mRNA than poorly differentiated ones. These results suggest that active lymphangiogenesis is not required for lymphovascular spread of pancreatic cancer. VEGF-C may promote local tumor growth via paracrine signaling to stromal cells expressing VEGFR-3 and support the entry of cancer cells into peritumoral lymphatics. Furthermore, loss of Prox1 function may be a driving force behind pancreatic carcinoma progression.

Expression level of vascular endothelial growth factor-C and -A in cultured human oral squamous cell carcinoma correlates respectively with lymphatic metastasis and angiogenesis when transplanted into nude mouse oral cavity

Angiogenesis is induced by various angiogenic factors including vascular endothelial growth factors (VEGFs), such as VEGF-A, -B, -C and -D, and is involved in tumor progression and metastasis. In an effort to define the expression pattern of VEGFs in oral squamous cell carcinoma (OSCC) and its correlation with clinicopathological factors, we determined the expression levels of VEGFs in OSCC cell lines (HSC-2, HSC-3, HSC-4 and OSC-19) by quantitative RT-PCR and examined their relationship with regional lymph node (LN) and distant metastasis, intratumoral microvessel density (MVD) in tumor transplanted nude mice. We found that HSC-2 and OSC-19 expressed significantly higher levels of VEGF-A and VEGF-C, and caused frequent regional LN metastasis and higher MVD than did the other cell lines. Since VEGF-C is a lymphangiogenic factor, these results suggest that expression of VEGF-C is a useful predictor for LN metastasis.