Lymphangiogenic and angiogenic microvessel density in human primary sporadic colorectal carcinoma

Utility of CD34 in Assessing Microvessel Density and Its Correlation With Clinicopathological Parameters in Colorectal Carcinoma Patients

Currently, the most commonly practiced method of reporting cases of colorectal carcinoma is done according to guidelines provided by the College of American Pathologists (8th edition) and the Royal College of Pathologists (UK). These guidelines include various histopathological parameters like tumor site, extent, histologic type, grade, margins, tumor budding, lymphovascular invasion, and perineural invasion. However, in the present guidelines, the immunohistochemistry-based marker of mean vessel density (MVD) has not been addressed as an important parameter. The present study gives an overview of the importance of MVD. MVD was statistically significant when correlated with tumor size, lymph node metastasis, grade, and vascular invasion. However, no statistical significance was observed when compared with age, perineural invasion, and stage of the tumor.

Immunoexpression of GLUT-1 and angiogenic index in pleomorphic adenomas, adenoid cystic carcinomas, and mucoepidermoid carcinomas of the salivary glands

This study aimed to evaluate and compare the immunoexpression of glucose transporter-1 (GLUT-1) and angiogenic index between pleomorphic adenomas (PAs), adenoid cystic carcinomas (ACCs), and mucoepidermoid carcinomas (MECs) of the salivary glands, and establish associations with the respective subtype/histological grade. Twenty PAs, 20 ACCs, and 10 MECs were submitted to morphological and immunohistochemical analysis. GLUT-1 expression was semi-quantitatively evaluated and angiogenic index was assessed by microvessel counts using anti-CD34 antibody. Higher GLUT-1 immunoexpression was observed in the MECs compared to PAs and ACCs (p = 0.022). Mean number of microvessels was 66.5 in MECs, 40.4 in PAs, and 21.2 in ACCs (p < 0.001). GLUT-1 expression and angiogenic index showed no significant correlation in the tumors studied. Results suggest that differences in biological behavior of the studied tumors are related to GLUT-1. Benign and malignant salivary gland tumors differ in the angiogenic index; however, angiogenesis may be independent of the tumor cell's metabolic demand.

Lymphangiogenesis and colorectal cancer

Lymphatic metastasis is an important event in the progress of metastasis in colorectal cancer (CRC). The purpose of this article is to assess the role of lymphangiogenesis on CRC. In peritumoral areas of CRC, the lymphatic microvessel density (LMVD) is higher than those in normal colorectal tissues. Morever, the high LMVD is correlated with DFS and local recurrence in CRC. The VEGF-C/VEGF-D/VEGFR-3 pathway, sonic hedgehog (Shh) signaling pathway and extracellular matrix (ECM) are involved in the regulation of lymphangiogenesis in CRC. Inhibition of the VEGF-C/VEGF-D/VEGFR-3 pathway by specific antibodies has been reported to efficiently inhibit experimental tumor lymphangiogenesis and metastasis in animal experiments. Although lymphangiogenesis has been reported to play an important role in the occurrence of colon cancer and to be associated with prognosis, it remains unclear whether it is a valid therapeutic target molecule. Further study of the potential of targeting this process for anti-lymphatic therapies is worthwhile.

Development and Validation of a Histological Method to Measure Microvessel Density in Whole-Slide Images of Cancer Tissue

Despite all efforts made to develop predictive biomarkers for antiangiogenic therapies, no unambiguous markers have been identified so far. This is due to among others the lack of standardized tests. This study presents an improved microvessel density quantification method in tumor tissue based on stereological principles and using whole-slide images. Vessels in tissue sections of different cancer types were stained for CD31 by an automated and validated immunohistochemical staining method. The stained slides were digitized with a digital slide scanner. Systematic, uniform, random sampling of the regions of interest on the whole-slide images was performed semi-automatically with the previously published applications AutoTag and AutoSnap. Subsequently, an unbiased counting grid was combined with the images generated with these scripts. Up to six independent observers counted microvessels in up to four cancer types: colorectal carcinoma, glioblastoma multiforme, ovarian carcinoma and renal cell carcinoma. At first, inter-observer variability was found to be unacceptable. However, after a series of consensus training sessions and interim statistical analysis, counting rules were modified and inter-observer concordance improved considerably. Every CD31-positive object was counted, with exclusion of suspected CD31-positive monocytes, macrophages and tumor cells. Furthermore, if interconnected, stained objects were considered a single vessel. Ten regions of interest were sufficient for accurate microvessel density measurements. Intra-observer and inter-observer variability were low (intraclass correlation coefficient > 0.7) if the observers were adequately trained.

Clinicopathological significance of vascular endothelial growth factor, thymidine phosphorylase and microvessel density in colorectal cancer

Colorectal cancer is a common malignant disease, the incidence of which is increasing worldwide, therefore, identifying novel prognostic factors to improve adjuvant therapeutic strategies or postoperative monitoring is required. Angiogenesis, which is assessed by microvessel density (MVD), is significant in tumor growth and metastasis. However, the association between angiogenesis and clinical outcome remains controversial. In the present study, 84 surgically resected cases of colorectal cancer were examined to clarify the clinicopathological significance of vascular endothelial growth factor (VEGF), thymidine phosphorylase (TP) and cluster of differentiation (CD)34 expression levels. VEGF expression was identified to be significantly correlated with TP expression (r=0.45; P<0.0001) and MVD in the high VEGF expression group was observed to be significantly greater than that in the low VEGF expression group (P=0.0194). In the Dukes' stage D group, the MVD in the high TP expression group was significantly greater than that in the low TP expression group (P=0.0149). High VEGF expression was subsequently correlated with a short overall survival rate for patients exhibiting lymph node metastasis (P=0.0128); however, there was no significant difference in overall survival rate regarding the expression levels of TP and CD34. The results of the present study indicate that VEGF expression may serve as a prognostic factor for colorectal cancer patients exhibiting lymph node metastasis. Furthermore, angiogenesis, as assessed by MVD, is an important prognostic factor for tumor growth at the primary site.

Impact of KITENIN on tumor angiogenesis and lymphangiogenesis in colorectal cancer

Angiogenesis and lymphangiogenesis are involved in the dissemination of tumor cells from solid tumors to regional lymph nodes and various distant sites. KAI1 COOH-terminal interacting tetraspanin (KITENIN) contributes to tumor progression and poor clinical outcomes in various cancers including colorectal cancer. The aim of the present study was to evaluate whether KITENIN affects tumor angiogenesis and lymphangiogenesis in colorectal cancer. A KITENIN small interfering RNA vector was used to silence KITENIN expression in colorectal cancer cell lines including DLD1 and SW480 cells. To evaluate the ability of KITENIN to induce angiogenesis and lymphangiogenesis in human umbilical vein endothelial cells (HUVECs) and lymphatic endothelial cells (HLECs), we performed Matrigel invasion and tube formation assays. Immunohistochemistry was used to determine the expression of KITENIN in colorectal cancer tissues. Angiogenesis and lymphangiogenesis were evaluated by immunostaining with CD34 and D2-40 antibodies. KITENIN silencing inhibited both HUVEC invasion and tube formation in the DLD1 and SW480 cells. KITENIN silencing led to decreased expression of the angiogenic inducers vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor-1α and increased expression of the angiogenic inhibitor angiostatin. KITENIN silencing did not inhibit either HLEC invasion or tube formation in all tested cells, but it resulted in decreased expression of the lymphangiogenic inducer VEGF-C. KITENIN expression was significantly associated with tumor stage, depth of invasion, lymph node and distant metastases and poor survival. The mean microvessel density was significantly higher in the KITENIN-positive tumors than that in the KITENIN-negative tumors. However, the mean lymphatic vessel density of KITENIN-positive tumors was not significantly higher than that of the KITENIN-negative tumors. These results suggest that KITENIN promotes tumor progression by enhancing angiogenesis in colorectal cancer.

Podoplanin‑positive cancer cells at the edge of esophageal squamous cell carcinomas are involved in invasion

Podoplanin (PDPN) is a well established lymphatic endothelial marker and has frequently been observed in cancer cells at the edge of cancer masses. Previous studies investigating the association between PDPN expression and patient prognosis have had contradictory results. In the present study, it was hypothesized that the different locations of PDPN‑positive cells may explain these varying results. The present study aimed to focus on PDPN expression at the edge of esophageal cancer cell nests. In order to analyze the clinical significance of this PDPN expression, immunohistochemistry was performed using esophageal cancer tissue microarrays. PDPN expression at the edge of the cancer cell nest was found to be significantly associated with invasion (P<0.05) and poor prognosis (P<0.001) in patients with cancer. To further investigate the role of PDPN expression in cancer cells, the PDPN gene was cloned and transfected into esophageal squamous cell carcinoma (ESCC) cell lines. PDPN expression was also knocked down using small interfering RNA. PDPN‑positive cancer cells were found to exhibit invasion characteristics. Thus, PDPN expression at the edge of a cancer cell nest may indicate invasion and represent a poor prognostic factor for ESCCs.

Can vascular endothelial growth factor and microvessel density be used as prognostic biomarkers for colorectal cancer? A systematic review and meta-analysis

Background. Vascular endothelial growth factor (VEGF) and microvessel density (MVD) are associated with greater incidence of metastases and decreased survival. Whether they can be used as prognostic indicators of colorectal cancer (CRC) is still controversial. Methods. The authors performed a meta-analysis using the results of a literature search of databases of PubMed and EMBASE, and the references of articles included in the analysis. Meta-analysis was performed using random effects model and hazard ratios (HRs) and 95% confidence intervals (CIs) as effect measures. Results. Twenty studies contributed to the analysis of VEGF, of which 16 were used for overall survival (OS) and 9 for disease-free survival (DFS). High VEGF levels has a relationship with unfavorable survival (OS: HR = 1.98, 95% CI: 1.30–3.02; DFS: HR = 2.10, 95% CI: 1.26–3.49) and a 4.22-fold increase in the rate of distant metastases. Analysis was performed on 18 studies for MVD; the results showed that patients with high MVD expression in tumors appeared to have poorer overall survival (HR = 1.39, 95% CI: 1.22–1.58) and were at a greater risk of having unfavorable clinical characteristics related to prognosis. Corresponding results were obtained from quantitative and/or qualitative analysis of clinicopathological. Conclusions. The meta-analysis demonstrates that VEGF and MVD can be used as prognostic biomarkers for CRC patients.

Insulin-like growth factor-1 induces lymphangiogenesis and facilitates lymphatic metastasis in colorectal cancer

AIM: To investigate the expression of insulin-like growth factor-1 (IGF-1)/insulin-like growth factor-1 receptor (IGF-1R) in colorectal cancer (CRC) tissues and to analyze their correlation with lymphangiogenesis and lymphatic metastasis.

METHODS: Immunohistochemistry was used to evaluate IGF-1 and IGF-1R expression and lymphatic vessel density (LVD) in 40 CRC specimens. The correlation between IGF-1/IGF-1R and LVD was investigated. Effects of IGF-1 on migration and invasion of CRC cells were examined using transwell chamber assays. A LoVo cell xenograft model was established to further detect the role of IGF-1 in CRC lymphangiogenesis in vivo.

RESULTS: Elevated IGF-1 and IGF-1R expression in CRC tissues was correlated with lymph node metastasis (r = 0.715 and 0.569, respectively, P < 0.05) and tumor TNM stage (r = 0.731 and 0.609, P < 0.05). A higher LVD was also found in CRC tissues and was correlated with lymphatic metastasis (r = 0.405, P < 0.05). A positive correlation was found between LVD and IGF-1R expression (r = 0.437, P < 0.05). Transwell assays revealed that IGF-1 increased the migration and invasion of CRC cells. In vivo mouse studies showed that IGF-1 also increased LVD in LoVo cell xenografts.

CONCLUSION: IGF-1/IGF-1R signaling induces tumor-associated lymphangiogenesis and contributes to lymphatic metastasis of CRC.

Prognostic and survival analysis of 837 Chinese colorectal cancer patients

AIM: To develop a prognostic model to predict survival of patients with colorectal cancer (CRC).

METHODS: Survival data of 837 CRC patients undergoing surgery between 1996 and 2006 were collected and analyzed by univariate analysis and Cox proportional hazard regression model to reveal the prognostic factors for CRC. All data were recorded using a standard data form and analyzed using SPSS version 18.0 (SPSS, Chicago, IL, United States). Survival curves were calculated by the Kaplan-Meier method. The log rank test was used to assess differences in survival. Univariate hazard ratios and significant and independent predictors of disease-specific survival and were identified by Cox proportional hazard analysis. The stepwise procedure was set to a threshold of 0.05. Statistical significance was defined as P < 0.05.

RESULTS: The survival rate was 74% at 3 years and 68% at 5 years. The results of univariate analysis suggested age, preoperative obstruction, serum carcinoembryonic antigen level at diagnosis, status of resection, tumor size, histological grade, pathological type, lymphovascular invasion, invasion of adjacent organs, and tumor node metastasis (TNM) staging were positive prognostic factors (P < 0.05). Lymph node ratio (LNR) was also a strong prognostic factor in stage III CRC (P < 0.0001). We divided 341 stage III patients into three groups according to LNR values (LNR1, LNR ≤ 0.33, n = 211; LNR2, LNR 0.34-0.66, n = 76; and LNR3, LNR ≥ 0.67, n = 54). Univariate analysis showed a significant statistical difference in 3-year survival among these groups: LNR1, 73%; LNR2, 55%; and LNR3, 42% (P < 0.0001). The multivariate analysis results showed that histological grade, depth of bowel wall invasion, and number of metastatic lymph nodes were the most important prognostic factors for CRC if we did not consider the interaction of the TNM staging system (P < 0.05). When the TNM staging was taken into account, histological grade lost its statistical significance, while the specific TNM staging system showed a statistically significant difference (P < 0.0001).

CONCLUSION: The overall survival of CRC patients has improved between 1996 and 2006. LNR is a powerful factor for estimating the survival of stage III CRC patients.

Clinical significance of lymph vessel density in T3 colorectal carcinoma

PURPOSE

The purpose of the present study is to characterise the lymphatic vessel density (LVD) in the T3 colorectal carcinoma and to correlate it with N status, grading and presence of tumour budding.

METHODS

A total of 56 cases of T3 colorectal carcinoma were retrieved from the pathology's archive of Klinikum Augsburg. All slides were stained immunohistochemically with D2-40 (lymphatic endothelium) and with pancytokeratin to assess the tumour budding. Tumour budding and lymph vessel density were investigated independently by BM and CC. The highest density of lymphatic vessels was counted both in tumour centre (ILVD) and at the periphery of the tumour (PLVD) within an area of 0.24 mm(2).

RESULTS

Due to the strong intra-observer (BM and CC) difference in ILVD and PLVD, all cases were re-evaluated establishing a consensus that has been used for the further analyses. There was a significant difference between PLVD and ILVD (12 ± 4 versus 6 ± 3; P < 0.001). Moreover, we found a non-significant trend towards high PLVD in the cases with nodal metastasis versus the negative one, 13 ± 5/hpf versus 11 ± 4 (P = 0.072). There was no association between tumour budding and ILVD and PLVD (P = 0.249 and 0.38).

CONCLUSION

Colorectal carcinoma induces lymphangiogenesis. A higher PLVD could increase the capability of cancer cell to invade the lymphatic system. However, the obvious difficulties in immunohistochemical evaluation and the rather small differences between nodal positive and negative cases in T3 colorectal cancer seem to limit the clinical value of LVD evaluation.

Roles of VEGF-C and Smad4 in the lymphangiogenesis, lymphatic metastasis, and prognosis in colon cancer

BACKGROUND/AIMS

We combined two different signal pathways on transforming growth factor β1 (TGF-β1)-Smad and vascular endothelial growth factor C (VEGF-C)/VEGF receptors for exploring changes in pathway members and their influence on lymphangiogenesis and clinicopathological features.

MATERIALS AND METHODS

Expression of TGF-β1, TGF-βRII, Smad4, VEGF-C, and VEGFR-3 was immunohistochemically evaluated in 147 colon cancer patients who were followed up for 5 years.

RESULTS

Lymphatic vessel density in colon cancer tissues was significantly higher than in normal colonic tissues. Smad4 expression negatively correlated with lymphatic vessel count and VEGF-C expression. VEGF-C expression positively correlated with lymphatic vessel count. Analysis using the Kaplan-Meier method indicated that patients with VEGF-C-positive tumors had significantly shorter overall survival and tumor-free survival time than those with VEGF-C-negative tumors. Patients with Smad4-negative tumors had significantly shorter overall survival and tumor-free survival time than those with Smad4-positive tumors.

CONCLUSIONS

Both Smad4 and VEGF-C are involved in lymphangiogenesis and lymphatic metastasis. Smad4 and VEGF-C expression may be clinically useful indicators for prognostic evaluation in colon cancer patients.

The clinical value of von Willebrand factor in colorectal carcinomas

BACKGROUND

To identify the value of von Willebrand factor (vWF) as a clinical marker in colorectal carcinoma (CRC).

METHODS

Plasma levels of vWF were measured in 79 patients with UICC Stage I-IV CRC at time of operation and correlated with TNM categories, levels of the carcinoembryonic antigen (CEA), blood groups (BG) and 19 controls (CO). CO included cancer-free patients without bacterial or viral infections. For tissue analysis paraffin embedded tumour and mucosa sections of operation specimens were stained immunohistochemically for vWF and compared to vWF plasma levels as well as to TNM categories.

RESULTS

VWF plasma levels in CRC patients were significantly dependent on blood groups (p=0.012) and elevated compared to the normal ranges as well as to controls (BG 0: p=0.668, BG A/AB/B: p=0.020). CRC-Patients over 60 years of age presented with significantly higher vWF levels than patients below 60 years (BG 0: p=0.005; BG A/AB/B: p=0.035). There was no correlation of vWF plasma levels and UICC stages in CRC. Patients with elevated vWF plasma levels also presented with elevated CEA levels, but significance was missing (p=0.080). VWF concentration within the tumour tissue was independent of concentration within normal mucosa, blood groups, histopathological characteristics and did not correlate with plasma vWF levels.

CONCLUSION

VWF plasma levels are elevated in CRC patients, but not in a stage dependent manner. Besides the tumour at least blood groups and age mainly influence plasma vWF levels. In our opinion vWF as a routinely used clinical marker in CRC cannot be recommended.

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

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

Role of endoglin and VEGF family expression in colorectal cancer prognosis and anti-angiogenic therapies

Colorectal cancer (CRC) is one of the cancer models and most of the carcinogenic steps are presently well understood. Therefore, successful preventive measures are currently used in medical practice. However, CRC is still an important public health problem as it is the third most common cancer and the fourth most frequent cause of cancer death worldwide. Nowadays, pathologic stage is a unique and well-recognized prognostic indicator, however, more accurate indicators of the biologic behavior of CRC are expected to improve the specificity of medical treatment. Angiogenesis plays an important role in the growth and progression of cancer but its role as a prognostic factor is still controversial. Probably the most important clinical implication of tumor angiogenesis is the development of anti-angiogenic therapy. The goal of this review is to critically evaluate the role of angiogenic markers, assessed by either endoglin-related microvessel density or expression of vascular endothelial growth factor family members in the CRC setting and discuss the role of these angiogenic markers in anti-angiogenic therapies.

Immunohistochemical analysis of vascular density and area in colorectal carcinoma using different markers and comparison with clinicopathologic prognostic factors

Analysis of blood and lymphatic vessel in colorectal cancer is controversial in the literature, possibly due to variations in the methods of analysis. In this study, it was aimed to search for a reliable approach in the quantification of angio- and lymphangiovascular density and area as a prognostic factor and to compare such vessel counts in normal mucosa, adenomas and cancer. A retrospective study was performed on 60 sporadic colorectal cancer, 30 colorectal adenomas, and 10 colorectal non-neoplastic lesions. Archival tissues were submitted to immunohistochemical evaluation using antibodies to CD31, CD34, CD105, VEGF-A, VEGF-C, and D2-40. Microvessel density and total vascular area were determined by computer image analysis and values were compared in the three groups of lesions; the prognostic value of these parameters was evaluated in the group of colorectal cancer. Most markers showed progressive vessel counts from non-neoplastic tissue to carcinoma, both for microvessel density and total vascular area. Only microvessel density determined by CD34 in the central areas of the cancer correlated with recurrence/metastasis (p = 0.04) and survival (p = 0.02). Different methods of quantification (microvessel counting versus estimation of total vascular area), immunohistochemical markers (pan-endothelial marker versus neovessels and lymphatic markers), and areas of analysis (periphery versus inner portions of the lesion) were assessed using image analysis. The results corroborate the increase in vascularization of carcinoma and suggest that microvessel density determined by immunostaining for CD34 in the inner portion of the tumor might represent a prognostically relevant parameter in colorectal cancer.

Podoplanin expression in cancerous stroma induces lymphangiogenesis and predicts lymphatic spread and patient survival

CONTEXT

Podoplanin is a mucin-type glycoprotein and a lymphatic endothelial marker. Immunohistochemical staining for podoplanin is currently used as a routine pathologic diagnosis tool in Japan to identify lymphatic invasion of cancer cells. Recent reports suggest that podoplanin and other proangiogenic molecules are expressed in stromal fibroblasts and myofibroblasts.

OBJECTIVE

To analyze the distribution of podoplanin expression in tumor stroma and its clinical and biologic significance.

DESIGN

We performed immunohistochemistry for podoplanin on tissue microarrays from 1350 cases of 14 common cancer types.

RESULTS

Two hundred eighty-seven of 662 cases (43%) showed podoplanin expression in the stromal cells within cancer nests. Stromal podoplanin expression in 14 common cancer types was significantly associated with tumor stage (P < .001), lymph node metastases (P < .001), lymphatic invasion (P  =  .02), and venous invasion (P < .001). The stromal cells positive for podoplanin were also positive for α-smooth muscle actin but negative for desmin, confirming a myofibroblasts phenotype. In contrast, myofibroblasts in inflammatory fibrotic lung diseases were podoplanin negative. Lymphatic vessel density was greater in the stromas with podoplanin expression than in the stroma lacking podoplanin-expressing stromal cells (P  =  .01). Survival data were available for non-small cell lung cancer. Stromal podoplanin expression was associated with poorer prognosis in adenocarcinoma (P < .001) and remains statistically significant after adjustment for sex, age, and stage (P  =  .01).

CONCLUSION

Our data indicate that podoplanin expression in stromal myofibroblasts may function as a proangiogenic biomarker and may serve as a predictive marker of lymphatic/vascular spread of cancer cells and a prognostic marker of patient survival.

Podoplanin expression in cancerous stroma induces lymphangiogenesis and predicts lymphatic spread and patient survival

CONTEXT

Podoplanin is a mucin-type glycoprotein and a lymphatic endothelial marker. Immunohistochemical staining for podoplanin is currently used as a routine pathologic diagnosis tool in Japan to identify lymphatic invasion of cancer cells. Recent reports suggest that podoplanin and other proangiogenic molecules are expressed in stromal fibroblasts and myofibroblasts.

OBJECTIVE

To analyze the distribution of podoplanin expression in tumor stroma and its clinical and biologic significance.

DESIGN

We performed immunohistochemistry for podoplanin on tissue microarrays from 1350 cases of 14 common cancer types.

RESULTS

Two hundred eighty-seven of 662 cases (43%) showed podoplanin expression in the stromal cells within cancer nests. Stromal podoplanin expression in 14 common cancer types was significantly associated with tumor stage (P < .001), lymph node metastases (P < .001), lymphatic invasion (P  =  .02), and venous invasion (P < .001). The stromal cells positive for podoplanin were also positive for α-smooth muscle actin but negative for desmin, confirming a myofibroblasts phenotype. In contrast, myofibroblasts in inflammatory fibrotic lung diseases were podoplanin negative. Lymphatic vessel density was greater in the stromas with podoplanin expression than in the stroma lacking podoplanin-expressing stromal cells (P  =  .01). Survival data were available for non-small cell lung cancer. Stromal podoplanin expression was associated with poorer prognosis in adenocarcinoma (P < .001) and remains statistically significant after adjustment for sex, age, and stage (P  =  .01).

CONCLUSION

Our data indicate that podoplanin expression in stromal myofibroblasts may function as a proangiogenic biomarker and may serve as a predictive marker of lymphatic/vascular spread of cancer cells and a prognostic marker of patient survival.

Lymphangiogenesis: A new player in cancer progression

Lymph node metastasis is the hallmark of colon cancer progression, and is considered one of the most important prognostic factors. Recently, there has been growing evidence that tumor lymphangiogenesis (formation of new lymphatic vessels) plays an important role in this process. Here, we review the latest findings of the role of lymphangiogenesis in colorectal cancer progression, and discuss its clinical application as a biomarker and target for new therapy. Understanding the molecular pathways that regulate lymphangiogenesis is mandatory to pave the way for the development of new therapies for cancer. In the future, tailored treatments consisting of combinations of chemotherapy, other targeted therapies, and anti-lymphangiogenesis agents will hopefully improve patient outcomes. This progression to the clinic must be guided by new avenues of research, such as the identification of biomarkers that predict response to treatment.

Intratumoral as well as peritumoral lymphatic vessel invasion correlates with lymph node metastasis and unfavourable outcome in colorectal cancer

The aim of this study was to assess the intratumoral and peritumoral distribution of lymphatic vessel density (LVD) and lymphatic vessel invasion (LVI) in colorectal cancer and their relationships with patients' clinicopathological characteristics and survival. Paraffin sections of 81 primary colorectal cancers were examined by immunohistochemical staining using monoclonal antibody D2-40. Peritumoral LVD was significantly higher than intratumoral LVD (P = 0.000). Both intratumoral LVD and peritumoral LVD were correlated with the presence of LVI (P = 0.006 and P = 0.003, respectively). LVI, intratumoral LVI and peritumoral LVI were identified, respectively in 38, 28 and 32% of the samples investigated. Both intratumoral LVI and peritumoral LVI were correlated with lymph node metastasis (P = 0.030 and P = 0.014, respectively). Lymph node metastasis, the presence of intratumoral LVI and peritumoral LVI were adversely associated with the 5-year overall survival in a univariate analysis (P = 0.001, P = 0.011 and P = 0.017, respectively). Multivariate analysis using Cox proportional hazard model showed that neither intratumoral LVI nor peritumoral LVI was an independent prognostic factor of overall survival. The results of this study demonstrated that intratumoral as well as peritumoral LVI was associated with lymph node metastasis and adverse outcome in colorectal cancer.

Fibroblastic reaction and vascular maturation in human colon cancers

PURPOSE

The objective of the present study was to provide evidence for the hypothesis of fibroblasts and the desmoplastic reaction, respectively, to impact the formation and maturation of the vascular network in human colon tumours via a retrospective in situ study. An in vivo xenograft model was evaluated to verify its potential for fibroblast-related functional studies.

MATERIALS AND METHODS

In situ: Fiftytwo G2/G3 colon tumours were histomorphologically categorised into low (<50%), medium (50-75%) and high (>75%) grade desmoplasia based on hematoxylin/eosin and Elastica van Gieson stained paraffin sections. Low and high grade desmoplastic tumours were identified and stained for endothelial and pericyte markers to morphometrically analyse microvessel count (MVC), vascular surface area (VSA) and vascular maturation status. In vivo: One out of three established subcutaneous xenograft model in NMRI (nu/nu) mice was adapted to monitor the impact of primary human fibroblasts on xenograft formation and morphology.

RESULTS

Vascular structures in human colon tumours are predominantly located in the fibroblastic stromal regions. Highly desmoplastic tumours, however, have significantly lower MVC and VSA values at the invasion front with signs for augmented vascular maturation as compared with low grade desmoplastic colon cancers. Our in vivo approach verified that only high proportions of co-injected normal fibroblasts accelerate xenograft formation of HCT-116 colon cancer cells.

CONCLUSIONS

The in situ data clearly support the hypothesis of fibroblasts to contribute to vascular maturation phenomena in colon cancers. The in vivo design of only 500 tumour cells co-injected with normal fibroblast is feasible, results in 100% engraftment and is the basis for further developments.

Comparison of blood neoangiogenesis and lymphatic vascularization in colorectal adenomas from patients with and without concomitant colorectal cancer

Blood and lymphatic vessel proliferation is essential for tumor growth and progression. Most colorectal carcinomas develop from adenomas (adenoma-carcinoma sequence) in a process due to accumulation of molecular genetic alterations. About 5% of adenomatous polyps are expected to become malignant, but data on the differential angiogenic patterns of these lesions in patients with and without concomitant cancer are missing. The aim of the present study is to compare the angiogenic and lymphatic patterns of adenomatous polyps from patients with and without sporadic cancer. Thirty adenomatous polyps (15 from patients with another principal malignant lesion, and 15 from patients without cancer) were submitted to immunohistochemical staining for CD105 (marker for neoangiogenesis) and D2-40 (marker for lymphatic endothelium). Microvessel density and total vascular area were determined by computer image analysis to quantify the immunostained and total areas, and to assess the number of microvessels. Adenomas from patients with carcinoma showed significantly higher values of total vascular area determined by immunostaining for CD105 (cutoff value = 4386 microm(2); P = 0.019) and of lymphatic microvessel density determined by immunostaining with D2-40 (cutoff value = 11.5; P = 0.041) when compared with those from patients without cancer. The present data indicate a significant increase in blood microvascular area and in lymphatic microvascular counts in adenomas removed from patients with cancer.

Study on relationship between angiogenesis and micrometastases of peripheral blood in breast cancer

PURPOSE

To investigate the relationship between microvessel density, expression of vascular endothelial growth factor A (VEGF-A) and micrometastases in peripheral blood of patients with breast cancer.

METHOD

Microvessel density (MVD) and expression of VEGF-A were detected by immunohistochemistry S-P. Nested RT-PCR was introduced to detect the expression of hMAM mRNA in peripheral blood of all cases.

RESULT

Average MVD was 28.95 +/- 6.95 microvessels/100x and positive rate of VEGF-A was 64.0% (32/50) in 50 cases with breast cancer. MVD count and expression of VEGF-A were related to tumor size, metastasis of axillary lymph nodes and clinical stages (P < 0.05), independent of age and histological classification (P > 0.05). The positive rate of hMAM mRNA in peripheral blood was 34.0% (17/50), which correlated with lymphatic metastasis and clinical stages (P < 0.05), independent of pathological category, menopause and hormone receptor (P > 0.05). MVD count and positive rate of VEGF-A in breast cancer with positive expression of hMAM mRNA was obviously higher than those without hMAM mRNA expression (chi (2) = 5.766, P = 0.032; t = 5.37, P = 0.002).

CONCLUSIONS

MVD count and positive expression of VEGF-A closely correlated to hMAM mRNA released from tumor cells in the circulation. hMAM mRNA is expected to become a valuable marker for further study on micrometastases of breast cancer.