Tumor lymphangiogenesis in inflammatory breast carcinoma: a histomorphometric study.

PURPOSE: At the time of diagnosis, metastatic dissemination of tumor cells via the lymphatic system has occurred in nearly all patients with inflammatory breast cancer (IBC). The objective of this study was twofold: (a) to determine which is the most suitable marker of lymph vessels in primary breast tumors and (b) to compare histomorphometric lymph vessel variables in IBC and non-IBC. EXPERIMENTAL DESIGN: Serial sections of 10 IBCs and 10 non-IBCs were immunostained for D2-40, LYVE-1, podoplanin, and PROX-1. Relative lymph vessel area, lymph vessel perimeters, and counts and lymphatic endothelial cell proliferation (LECP) were then measured in D2-40/Ki-67 double-immunostained sections of 10 normal breast tissues, 29 IBCs, and 56 non-IBCs. RESULTS: D2-40 was the most suitable antibody for staining peritumoral and intratumoral lymph vessels. D2-40-stained intratumoral lymph vessels were present in 80% of non-IBCs and 82.8% of IBCs (P = 0.76). In non-IBC, lymph vessels located in the tumor parenchyma were smaller and less numerous than those at the tumor periphery (P < 0.0001) whereas in IBC, intratumoral and peritumoral variables were not significantly different. The mean relative tumor area occupied by lymph vessels was larger in IBC than in non-IBC (P = 0.01). LECP at the tumor periphery was higher in IBC than in non-IBC: median LECP was 5.74% in IBC versus 1.83% in non-IBC (P = 0.005). CONCLUSIONS: The high LECP in IBC suggests that lymphangiogenesis contributes to the extensive lymphatic spread of IBC.     

Intratumoral lymphatics are essential for the metastatic spread and prognosis in squamous cell carcinomas of the head and neck region

Head and neck squamous cell carcinomas (HNSCCs) frequently disseminate to regional lymph nodes. To investigate the possible mechanisms involved, we studied the expression of cancer cell adhesion molecules together with lymphatic vascular and blood vascular markers in a panel of 97 primary HNSCC tumors and correlated expression levels with conventional clinicopathological parameters and with long-term prognosis. In particular, we measured the density of intratumoral and peritumoral lymph vessels as assessed with the marker lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) and the density of tumor CD44, a receptor up-regulated in many metastatic cancers. Intratumoral LYVE-1(+) lymphatic vessels were clearly associated with a higher risk for local relapse as well as with poor disease-specific prognosis (P = 0.02 and 0.0009, respectively). In contrast, a high density of peritumoral LYVE-1(+) vessels was a sign of favorable survival (P = 0.05). Strong primary tumor CD44 expression was associated with a poor prognosis, an increased risk of local recurrence (P = 0.03 and 0.02, respectively), and an increase in resistance to radiation therapy (P = 0.03). CD44 was the only factor with an independent prognostic value for the disease-specific overall survival (P = 0.04). Our results suggest that intratumoral lymphatics play a greater role than peritumoral lymphatics in nodal metastasis of HNSCC and that tumor CD44 levels can predict sensitivity to radiation therapy. These parameters may be useful predictive and prognostic tools in the clinical management of HNSCC.     

Intratumoral lymphangiogenesis and lymph node metastasis in head and neck cancer

How tumors access and spread via the lymphatics is not understood. Although it is clear that dissemination via the blood system involves hemangiogenesis, it is uncertain whether tumors also induce lymphangiogenesis or simply invade existing peritumoral vessels. To address the issue we quantitated tumor lymph vessels in archival specimens of head and neck cancer by immunostaining for the recently described lymphatic endothelial marker LYVE-1, the vascular endothelial marker CD34, and the pKi67 proliferation marker, correlating lymph vessel density and proliferation index with clinical and pathological variables. Discrete "hotspots" of intratumoral small proliferating lymphatics were observed in all carcinomas, and a high intratumoral lymph vessel density was associated with neck node metastases (n = 23; P = 0.027) and an infiltrating margin of tumor invasion (P = 0.046) in the oropharyngeal subgroup. Quantitation of the lymphangiogenic growth factor vascular endothelial growth factor C by real-time PCR and immunohistochemistry revealed higher levels of mRNA in tumor tissue than in normal samples (n = 8; P = 0.017), but no obvious correlation with intratumoral lymphatics. Our results provide new evidence that proliferating lymphatics can occur in human cancers and may in some cases contribute to lymph node metastasis.     

Mannose receptor (MR) and common lymphatic endothelial and vascular endothelial receptor (CLEVER)-1 direct the binding of cancer cells to the lymph vessel endothelium

Although approximately 50% of cancers give rise to metastases via the lymphatic system, the mechanisms mediating this process have remained unknown. In this study, we have investigated the role of two lymphatic endothelial molecules, the mannose receptor (MR) and common lymphatic endothelial and vascular endothelial receptor (CLEVER)-1 in adhesion of malignant cells to the lymphatic endothelium, and analyzed their expression in two clinical series consisting of squamous cell cancers of the head and neck (n = 17) and breast cancers (n = 72). Affinity of the tested head and neck cancer cell lines to the lymphatic endothelium varied greatly, but adhesion of all cell lines was dependent on both the MR and CLEVER-1. Almost all cancer specimens contained peritumoral vessels that expressed CLEVER-1 and MR, and also the intratumoral lymph vessels often expressed them in both tumor types. However, only intratumoral expression of these molecules seems to be essential for metastatic spread to the regional lymph nodes. Only 8 (22%) of the 36 axillary node-negative breast carcinomas expressed the MR on the intratumoral lymph vessels as compared with 16 (50%) of the 32 node-positive carcinomas (P = 0.017), and all eight head and neck carcinoma patients with regional lymph node metastases at diagnosis had tumors that expressed CLEVER-1 on the intratumoral lymph vessels. These data suggest a role for both the MR and CLEVER-1 in directing the traffic of cancer cells within the lymphatic system.     

Can Lymphatic Vascular Density Be Used in Determining Metastatic Spreading Potential of Tumor in Invasive Ductal Carcinomas?

Regional lymph node status is the primary parameter determining treatment strategies and prognoses in breast cancer. Lymphatic vessels in primary tumor tissue play a significant role in lymphatic metastasis. The aim of this study was to investigate the correlation of intra- and peritumoral lymphatic microvessel densities (LVD) with prognostic parameters in breast cancer, including lymphatic invasion (LI). Lymphangiogenesis was investigated using D2-40 monoclonal antibody in 69 invasive ductal carcinoma cases who underwent mastectomy and axillary lymph node dissection. Positively stained microvessels were counted at 400× in dense lymphatic vascular foci (hotspots). Tumor LI was established when at least one neoplastic cell cluster was clearly visible inside a D2-40-positive lymph vessel. Relationships were sought between clinicopathological parameters and mean LVD and LI in primary tumor tissue. Peritumoral LVD was markedly higher than intratumoral LVD (p < 0.001). No significant relationship was found between intratumoral LVD and clinicopathological parameters (p > 0.05). However, significant relationships were detected between peritumoral LVD and LVI [H&E] (p = 0.04), number of lymphatic invasion [n/mm2, D2-40] (p = 0.001), tumor size (p = 0.01), lymph node status (p = 0.03), and tumor stage (p = 0.04). The immunohistochemical determination of LI and LVD can contribute to the prediction of a tumor’s biological behavior in invasive ductal carcinomas. Peritumoral LVD in primary tumor tissue is closely related to parameters influencing the prognosis of a tumor.     

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.     

乳腺癌患者新辅助化疗前后淋巴管密度检测

背景与目的:淋巴管生成在肿瘤经淋巴途径转移中所起的作用已成为近几年里新的研究热点,但目前的研究结果仍存在很多争议。本研究拟检测乳腺癌患者新辅助化疗前后的淋巴管密度(lymphatic vessel density,LVD)并与乳腺良性病变进行比较,以进一步明确淋巴管生成的意义及其在化疗过程中的变化。方法:45例原发性乳腺癌患者给予3个周期新辅助化疗并手术,免疫组化法标记肿瘤及26例纤维腺瘤标本中特异性淋巴管内皮标志物Podop lan in并计数LVD。结果:乳腺癌瘤周、瘤内的淋巴管阳性率分别为70.9%、19.8%。化疗前瘤周平均LVD为9.6,纤维腺瘤瘤周平均LVD为5.4,两者间差异有显著性(P=0.012)。化疗后瘤周平均LVD为3.3,与化疗前相比显著降低(P<0.001),化疗前、后瘤内平均LVD分别为1.9、0.9(P=0.055)。淋巴结转移阳性和阴性组的平均瘤周LVD分别为11.8、7.0(P=0.048)。化疗后客观缓解组化疗前后平均瘤周LVD值分别为9.8、2.0(P<0.001)。结论:与良性病变相比,乳腺癌瘤周LVD显著增高;有瘤内淋巴管存在;瘤周LVD与HER-2、腋淋巴结转移状态相关;化疗后瘤周LVD明显降低,而瘤内LVD无显著变化;化疗后瘤周LVD的降低程度与化疗疗效相关。     

Evidence of lymphangiogenesis in Warthin's tumor of the parotid gland

The details of the pathogenesis of cystadenolymphoma (Warthin's tumor) of the parotid gland are still unclear. Neovascularization is considered to be a pivotal factor for solid tumor progression and biological behavior of the tumor. Using double-labeling immunohistochemistry for LYVE-1 and CD34 (specific markers for lymphatic and vascular endothelial cells, respectively) this study analyzes lymphatic vessel density (LVD) and blood vessel density (BVD) in 10 Warthin's tumors and 10 pleomorphic adenomas of the parotid gland as well as in 5 normal parotid glands and 5 normal parotid lymph nodes. There was no significant difference in the intratumoral LVD and BVD among pleomorphic adenoma and normal parotid gland tissue. In contrast, the intratumoral LVD and BVD were significantly higher in Warthin's tumor than pleomorphic adenoma, normal parotid gland and parotid lymph node (P<0.0001 versus P<0.004). The increase in lymphatic vessels in Warthin's tumor suggests that epithelial tumor cells might promote lymphangiogenesis in this kind of lesions.     

Clinicopathological Significance of Tumor Lymphatic Vessel Density in Head and Neck Squamous Cell Carcinoma

Various studies have demonstrated that the lymphatic system is the additional route for solid tumor metastasis. Lymph nodes metastasis in Head and neck squamous cell carcinoma (HNSCC) is a major prognostic indicator for disease progression and a guide for therapeutic strategies. We conducted a study to compare intratumoral (IT) and peritumoral (PT) lymphatic vessel density (LVD) in HNSCC using lymphatic marker D2-40 and its correlation with lymph node metastasis, histological grading and other clinicopathological parameters. Fifty specimen of HNSCC with modified radical neck dissection tissue were included in the study group. Tissue from tumor, peritumoral tissue, tumor margin and all the lymph nodes were processed for paraffin wax blocks and histopathological diagnosis. Immunohistochemical profile of lymphatic vessels in intratumoral and peritumoral tissue was assessed by subjecting one section each from the tumor and peritumoral tissue to D2-40 immunostain. To determine LVD, four fields with the highest LVD (hot spots) were identified. The mean values were calculated by taking an average of all the measurements. The comparison of LVD between peritumoral and intratumoral area revealed significantly higher PT-LVD (P = 0.001). No significant association was seen between LVD, IT-LVD and PT-LVD and different age groups, gender, site of tumor, risk factors, size of tumor, tumor inflammation, pushing/infiltrating margin and stage of tumors. Significantly higher LVD, IT-LVD and PT-LVD was seen in association with lymph node metastasis. Both high intratumoral and peritumoral LVD were found significantly associated with the presence of lymph node metastasis, however lymphatic vessels were found to be significantly more numerous and larger in peritumoral areas as compared to intratumoral lymphatics. The specificity of D2-40 as a lymphatic endothelial marker was also confirmed. The results of our study support the possibility of using the determination of tumor lymphangiogenesis to identify patients of HNSCC who are at risk of developing the lymph node metastasis.     

VEGF-C induced lymphangiogenesis is associated with lymph node metastasis in orthotopic MCF-7 tumors

The spread of cancer cells to regional lymph nodes through the lymphatic system is the first step in the dissemination of breast cancer. In several human cancers including those of the breast and prostate, the expression of vascular endothelial growth factor C (VEGF-C) is associated with lymph node metastasis. Our study was undertaken to evaluate the effect of VEGF-C on metastasis of poorly invasive, estrogen dependent human MCF-7 breast cancer cells. MCF-7 breast cancer cells transfected with VEGF-C (MCF-7-VEGF-C) were grown as tumors in the mammary fat pads of nude mice implanted with subcutaneous estrogen pellets. Tumor lymphangiogenesis and lymph node metastasis were studied immunohistochemically using antibodies against lymphatic vessel hyaluronan receptor -1 (LYVE-1), VEGF receptor-3 (VEGFR-3), PECAM-1, pan-cytokeratin and estrogen dependent pS2 protein. Overexpression of VEGF-C in transfected MCF-7 cells stimulated in vivo tumor growth in xenotransplanted mice without affecting estrogen responsiveness. The resulting tumors metastasized to the regional lymph nodes in 75% (in 6 mice out of 8, Experiment I) and in 62% (in 5 mice out of 8, Experiment II) of mice bearing orthotopic tumors formed by MCF-7-VEGF-C cells whereas no metastases were observed in mice bearing tumors of control vector-transfected MCF-7 cells (MCF-7-Mock). The density of intratumoral and peritumoral lymphatic vessels was increased in tumors derived from MCF-7-VEGF-C cells but not MCF-7-Mock cells. Taken together, our results show that VEGF-C overexpression stimulates tumor lymphangiogenesis and induces normally poorly metastatic estrogen-dependent MCF-7 tumors to disseminate to local lymph nodes. These data suggest that VEGF-C has an important role in lymph node metastasis of breast cancer even at its hormone-dependent early stage.     

Dukes'B期直肠癌微淋巴管密度检测及其临床意义

背景与目的:Dukes)B期直肠癌患者预后差异大,临床未见淋巴结转移者可能有淋巴管微转移。本研究探讨Dukes)B期直肠癌微淋巴管密度(lymphaticvesseldensity,LVD)与预后的关系。方法:采用免疫组织化学方法标记淋巴管内皮特异性的淋巴管内皮细胞透明质烷受体-1(lymphaticvesselendothelialhyaluronanreceptor-1,LYVE-1),检测54例临床随访资料完整的Dukes)B期直肠癌患者癌组织、癌旁组织及正常肠组织的微淋巴管密度(200倍视野下微淋巴管数)。结果:54例中有11例(20.4%)癌组织、癌旁组织及正常肠组织中均未见LYVE-1阳性的棕黄染淋巴管,其余43例(79.6%)可见LYVE-1阳性的淋巴管。癌旁组织的微淋巴管密度(6.05±5.61)明显高于癌组织(0.89±0.66)(P<0.05)及正常肠组织(4.11±3.29)(P<0.05)。癌组织内的微淋巴管数目少,微淋巴管密度明显低于正常组织(P<0.05)。54例Dukes)B期直肠癌患者高淋巴管密度组(≥6)和低微淋巴管密度组(<6)患者复发、死亡等预后因素未见显著性差异(P>0.05)。结论:癌旁组织可能存在新生淋巴管生成,癌巢间隙的微淋巴管数目少。单纯通过微淋巴管密度的高低可能不足以评价Dukes)B期直肠癌患者的预后。     

Vascular endothelial growth factor-D induces lymphangiogenesis and lymphatic metastasis in models of ductal pancreatic cancer

The presence of lymphatic metastases is a strong indicator for poor prognosis in patients with ductal pancreatic cancer. In order to better understand the mechanisms controlling lymphatic growth and lymph node metastasis in human ductal pancreatic cancer, we analyzed the expression pattern of the vascular endothelial growth factor-D (VEGF-D), its receptor VEGF-receptor-3 (VEGFR-3) and the lymphatic endothelium-specific hyaluronan receptor LYVE-1 in a panel of 19 primary human ductal pancreatic tumors and 10 normal pancreas specimens. We further addressed the biological function of VEGF-D for induction of lymphatic metastasis in a nude mouse xenograft model using two human ductal pancreatic cancer cell lines with overexpression of VEGF-D. Compared to normal human pancreas, pancreatic cancer tissue showed overexpression of VEGF-D and VEGFR-3 in conjunction with a high lymphatic vascularization as determined by immunohistochemistry and in situ hybridization. Tumors derived from VEGF-D-overexpressing cells had a higher microvessel density compared to their mock-controls, as determined based on CD31 immunohistochemistry. Importantly, these tumors also revealed a significant induction of intra- and peritumoral lymphatics, as judged from immunohistochemical detection of LYVE-1 expression. This was associated with a significant increase in lymphatic vessel invasion by tumor cells and an increased rate of lymphatic metastases, as indicated by pan-cytokeratin reactive cells in lymph nodes. Our results suggest that VEGF-D plays a pivotal role in stimulating lymphangiogenesis and lymphatic metastasis in human ductal pancreatic cancer, and therefore represents a novel therapeutic target for this devastating disease.     

Peritumoral lymphatic vessel density and vascular endothelial growth factor C expression in early-stage squamous cell carcinoma of the uterine cervix.

PURPOSE: Lymphatic invasion and nodal metastasis plays a major role in the spread of cervical cancer; however, little is known about the mechanisms whereby tumor cells enter the lymphatic system. EXPERIMENTAL DESIGN: We examined the intra- and peritumoral lymphatic vessel density (LVD) using D2-40 immunohistochemistry in 111 cervical squamous cell carcinomas and correlated them with vascular endothelial growth factor (VEGF)-C expression, clinicopathologic tumor features, and outcome. RESULTS: Compared with benign cervix, intratumoral and peritumoral LVD was significantly increased (P < 0.0001). Peritumoral LVD was significantly higher than intratumoral LVD (P = 0.009). High peritumoral, but not intratumoral, LVD showed significant correlation with high tumor stage, lymphatic invasion, and nodal metastasis. VEGF-C showed increased expression at the invasive edge compared with the center of tumors (P < 0.0001) and correlated with high peritumoral LVD, lymphatic invasion, and nodal metastasis. High peritumoral LVD and VEGF-C expression at the invasive edge of tumors were associated with poor overall and recurrence-free survival in univariate analysis. In multivariate analysis, peritumoral LVD was the only independent term predictive of overall survival. CONCLUSIONS: Our findings suggest a potential role for VEGF-C in tumor-induced lymphangiogenesis represented by high peritumoral LVD, which may be one of the mechanisms leading to lymphatic invasion and metastatic spread. High peritumoral LVD may be an independent prognostic factor in early-stage cervical cancer.     

Lymphatic vessel density and vascular endothelial growth factor-C expression correlate with malignant behavior in human pancreatic endocrine tumors.

Metastatic dissemination of tumor cells to regional lymph nodes is a common early feature of many human cancers including pancreatic adenocarcinoma. In contrast, lymph node metastasis is more variably observed in pancreatic endocrine tumors. The objective of this study was to assess the lymphatic system of human pancreatic endocrine tumors and correlate this to clinical behavior. Immunohistochemistry was performed using antibodies to two recently identified markers of lymphatic endothelium, namely, LYVE-1 and podoplanin, and to the lymphangiogenic factor vascular endothelial growth factor (VEGF)-C. As has been reported previously, we observed that in the normal pancreas, islets of Langerhans are devoid of intra-islet lymphatics, but that lymphatics are present in connective tissue in association with ducts and blood vessels. We found that both benign and malignant pancreatic endocrine tumors contain intratumoral lymphatic vessels. Lymphatic vessel density was related to the size of the tumor in benign tumors and to the presence of liver metastasis but not to lymph node metastasis in malignant tumors. VEGF-C was expressed in tumor cells: 4 of 19 (21%) benign tumors were positive, whereas 6 of 9 (67%) borderline tumors and 9 of 11 (82%) carcinomas were positive. These findings strongly suggest that lymphangiogenesis occurs in pancreatic endocrine tumors and that lymphatic invasion and the development of metastases are associated with VEGF-C expression.     

Lymphatic vessel density in vocal cord carcinomas assessed with LYVE-1 receptor expression.

BACKGROUND AND PURPOSE: Early stage vocal cord carcinomas are usually cured by radiation therapy despite the use of portals that exclude the cervical lymph nodes. We investigated whether the lymphatic vessel density (LVD) of vocal cord carcinomas differs from that of other head and neck carcinomas. PATIENTS AND METHODS: Deparaffinized tissue from tumors of 60 patients diagnosed with head and neck squamous cell carcinoma (HNSCC) were immunostained for LYVE-1, a novel lymphatic vessel marker. Twenty-two had vocal cord carcinoma. Tumor blood vessel density (BVD) was assessed using immunostaining for CD31. RESULTS: Tumor overall LVD, including both intra- and peritumoral lymph vessels, was 10-fold lower than the BVD (5 counts/mm2 vs. 52 mm(-2), respectively). A high LVD was associated with a high BVD (P = .002), but neither was associated with the tumor size. Both tumor LVD and BVD were lower in vocal cord carcinomas than in HNSCCs arising at other sites (median, 0 vs. 7 mm(-2), P=.016; and median, 36 vs. 52 mm(-2), P = .006, respectively). Only one vocal cord carcinoma was associated with a regional metastasis at the time of the diagnosis. Among the rest of the cases tumor size was a better predictor for the presence of regional metastases than tumor BVD or LVD in a logistic regression model (odds ratio 2.2, 95% CI 1.1-4.5). CONCLUSION: Vocal cord carcinomas have a low lymph vessel density as compared with HNSCCs arising at other sites.     

Flt-4-positive vessel density correlates with vascular endothelial growth factor-d expression, nodal status, and prognosis in breast cancer.

PURPOSE: Metastasis to the regional lymph nodes through the lymphatic vessels is a common step in the progression of cancer and an important prognostic factor in many types of cancer. Recent evidence suggests that tumor lymphangiogenesis promotes lymphatic metastasis, and that the presence of Flt-4 on tumor blood and lymphatic vessels may play a important role in mediating lymphangiogenic factor-induced neovascularization. We assessed flt-4-positive vessel density (FVD) in breast cancer, and examined whether FVD associates with lymph node metastasis, VEGF-D expression, or prognosis. EXPERIMENTAL DESIGN: One hundred three invasive breast carcinomas with long-term follow-up were included in our study. Flt-4 was assessed using immunohistochemistry, then we analyzed the relationship between FVD and lymph node status, as well as VEGF-D expression and other established clinicopathological parameters. The relationship between FVD and prognosis was also investigated. RESULTS: Mean FVD of "hot spot" was 29.3 +/- 22.5 for each case. FVD was correlated significantly with lymph node metastasis (P < 0.0001), VEGF-D expression (P = 0.0019), tumor size (P = 0.0015), estrogen receptor (P = 0.0211), progesterone receptor (P = 0.0462), and c-erbB-2 (P = 0.0326). Survival curves determined by the Kaplan-Meier method and univariate analysis demonstrated that high FVD was associated with both worse disease-free survival (P = 0.0035) and overall survival (P = 0.0336). CONCLUSIONS: Increased FVD was correlated with lymph node metastasis and VEGF-D expression. High FVD may be a significant unfavorable prognostic factor for long-term survival in breast cancer. It is possible that Flt-4 becomes a target for antiangiogenic therapy to breast cancer.     

High density of peritumoral lymphatic vessels measured by D2-40/podoplanin and LYVE-1 expression in gastric cancer patients: an excellent prognostic indicator or a false friend?

Background

One of the most important prognostic indicators in gastric cancer is the presence of metastases in lymph nodes. Even now, little is known about lymphangiogenesis in neoplastic tissue, and little is also known about the transmission of a neoplastic cell from the tumor mass into a lymphatic vessel.

Methods

This study examined the relationships between the density of lymphatic vessels (LVD) stained immunohistochemically with lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and D2-40 (podoplanin) antibodies, the expression of vascular endothelial growth factor (VEGF)-C/D, selected clinical and pathomorphological factors, and the 5-year overall survival of gastric cancer patients.

Results

Statistical analysis showed no impact of increased intratumoral or peritumoral LVD on gastric cancer patient survival, irrespective of the protein used to stain lymphatic vessels. Analysis showed that the probability of overall survival was decreased in the cases with enhanced VEGF-D immunoreactivity (P = 0.0045).

Conclusion

The study showed that the studied markers cannot be used to determine the required extent of the surgical procedure, as they have no statistically significant correlation with the degree of progression of the cancer, the stage of the disease assessed according to the TNM 5th classification of malignant tumors, clinicopathological features, and patient survival. VEGF-D is the only marker that can be regarded as an unfavorable prognostic indicator for patients with advanced gastric cancer.     

淋巴管生成在直肠癌淋巴结转移中的作用及其对预后的影响

目的 观察直肠癌的淋巴管生成情况并探讨淋巴管生成在直肠癌淋巴结转移中的作用及对患者预后的影响.方法 以免疫组化方法对63例有完整随访资料的直肠癌及相应切缘正常组织的淋巴管进行染色,并测定淋巴管密度（lymphatic vessel density,LVD）;同时检测促淋巴管生长因子VEGF-C及其受体VEGFR-3的表达.结果 直肠癌肿瘤周边区淋巴管密度（peritumoral LVD,LVDpt）显著高于中心区淋巴管密度（intratumoral LVD,LVDit）及正常组织,而后两者相比差异无显著性;其中LVDpt与直肠癌VEGF-C及VEGFR-3的表达、淋巴结转移、低的5年生存率密切相关.结论 直肠癌主要是肿瘤周边区存在着淋巴管的生成,淋巴管的数量不但与直肠癌的淋巴结转移密切相关而且可以作为评价患者预后的一个可靠指标.     

A quantitative analysis of lymphatic vessels in human breast cancer, based on LYVE-1 immunoreactivity

This study was undertaken to determine the highly sensitive method for detecting tumour lymphatic vessels in all the fields of each slide (LV), lymphatic microvessel density (LMVD) and lymphatic vessel invasion (LVI) and to compare them with other prognostic parameters using immunohistochemical staining with polyclonal (PCAB) and monoclonal antibodies (MCAB) to the lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), and the pan-endothelial marker factor VIII in a series of 67 human breast cancers. In all LYVE-1-stained sections, LV (some of which contained red blood cells) were frequently found localised in extralobular stroma, dermis, connective tissue stroma and adjacent to artery and vein, but were rare within the intralobular stroma or the tumour body (3/67 cases) or areas of widespread invasion. In contrast small blood vessels were observed in intra- and extralobular stroma in the factor VIII-stained sections. Quantitation of vessel numbers revealed that LYVE-1/PCAB detected a significantly larger number of LV than either H&E or LYVE-1/MCAB (P<0.0001). LYVE-1/PCAB detected LVI in 25/67 cases (37.3%) and their presence was significantly associated with both lymph node metastasis (chi(2)=4.698, P=0.0248) and unfavourable overall survival (OS) (P=0.0453), while not relapse- free survival (RFS) (P=0.2948). LMVD had no influence for RFS and OS (P=0.4879, P=0.1463, respectively). Our study demonstrates that immunohistochemistry with LYVE-1/PCAB is a highly sensitive method for detecting tumour LV/LVI in breast cancer and LVI is a useful prognostic indicator for lymphatic tumour dissemination.     

Lymphatic endothelial cells, tumor lymphangiogenesis and metastasis: New insights into intratumoral and peritumoral lymphatics

Lymphatic metastasis of tumor cells represents a series of extremely complex and sequential processes that include dissemination and invasion into surrounding stromal tissues from primary tumors, penetration into lymphatic walls and implantation in regional lymph nodes, and extravasation or proliferation in parenchyma of target organs. Recent developments in lymphatic biology and research, especially the application of unique molecular markers specific for lymphatic endothelial cells (LECs), LYVE-1, Prox-1 and podoplanin have provided exciting new insights into the tumor microenvironment and LEC–tumor cell interface. To date, established factors for determining the behavior and prognosis of primary tumors have been emphasized morphologically and physiologically, i.e., lymphatic impairment and vessel density, dysfunction of lymphatic valves, interstitial fluid pressure, as well as a series of lymphangiogenic growth factors including VEGF-C/-D, and other cytokines and chemokines. Increasing knowledge of the tumor biological significance in lymphatics within the tumors (intratumoral lymphatics, ITLs) and at the tumor periphery (peritumoral lymphatics, PTLs) has greatly promoted understanding of tumor access into the lymphatic system by inducing lymphangiogenesis or by co-opting preexisting lymphatics. Therefore, the targeting PTLs and ITLs, which have been proposed as an important route for antimetastatic approach, are deemed worthy of further study in various animal tumor models and human tumors.