Peritumoral Lymphatic Density Research Articles

Participation of hypoxia-inducible factor-1α and lymphangiogenesis in metastatic and non-metastatic lower lip squamous cell carcinoma

This study evaluated the lymphatic density and HIF-1α immunoexpression in lower lip squamous cell carcinoma (LLSCC) and their correlation with clinicopathological (nodal metastasis, clinical stage, histological grade, recurrence and disease outcome) and survival parameters in 20 metastatic and 20 non-metastatic LLSCCs. Lymphatic density was established by counting microvessels (D2-40+) at the tumor core (intratumoral lymphatic density, ILD) and at the invasive front (peritumoral lymphatic density, PLD) and percentages of immunopositive cells for HIF-1α were established. No statistically significant differences in lymphatic densities in relation to clinicopathological parameters were observed (P > 0.05). All cases exhibited nuclear and cytoplasmic HIF-1α immunoexpression, with relatively high percentages of positivity, but this expression was not statistically different in relation to clinicopathological variables (P > 0.05). Positive correlations were observed between ILD and PLD (P = 0.002), and between nuclear HIF-1α immunoexpression at the tumor core and ILD (P = 0.001). The results suggest ILD and PLD are not directly related to the development of lymph node metastasis in LLSCC. The striking expression of HIF-1α suggests the involvement of this protein in the etiopathogenesis of LLSCCs, possibly stimulating lymphangiogenesis at the tumor core. However, this protein does not seem to exert a determining influence on the biological aggressiveness of these tumors.

Immunoexpression of HIF-1A and Measurement of Density in Lower Lip Squamous Cell Carcinoma in Metastatic and Non-Metastatic Cases: A Relationship With Prognosis Parameters

This study evaluated the immunoexpression of HIF-1α and correlated it with intratumoral and peritumoral lymphatic density in metastatic and non-metastatic lower lip squamous cell carcinoma (LLSCC). Study Design: This study evaluated the expression pattern and the percentage of cells immunostained for HIF-1α in 50 cases of LLSCC; 25 had regional nodal metastasis and 25 did not. Lymphatic microvessel density was determined. Results: HIF-1α exhibited predominantly diffuse cytoplasmic staining in tumors.

Intratumoral lymphangiogenesis in oral squamous cell carcinoma and its clinicopathological significance

Lymphatic metastasis has always been regarded as a major prognostic indicator for disease progression and as a guide for therapeutic strategies to oral squamous cell carcinoma (OSCC), but to date, how tumor cells access and spread via the lymphatics have not been fully elucidated. Whether tumor cells metastasize by expansion and invasion of pre-existing peritumoral lymphatics or by the induction and invasion of newly formed lymphatics within tumors is controversial. In order to address this issue and find out the clinicopathological significance of intratumoral lymphangiogenesis, we investigated 86 archival specimens from patients with OSCC, quantitating lymph vessels by immunostaining with D2-40. We also quantified lymphatic invasion and examined the possible associations of all the above parameters with clinicopathological features and outcome. Higher intratumoral lymphatic density (ILD) and peritumoral lymphatic density (PLD) were both significantly associated with the presence of lymph node metastasis at the time of diagnosis and the outcome of the post-operation biopsy of 77 patients (P = 0.001). Higher ILD was significantly associated with a higher incidence of intratumoral lymphatic invasion, peritumoral lymphatic invasion and recurrence of tumor (P = 0.001 and P = 0.041 and P = 0.001, respectively). Patients with higher ILD exhibited shorter 5-year cumulative and disease-free survival (P = 0.001). Thus, lymphangiogenesis indeed occurs in oral squamous cell carcinoma; ILD might be used as an index to inflect the aggression of the disease, to evaluate the status of lymphatic metastasis, to separate patients at higher risk of an adverse clinical outcome.

Prognostic Significance of Intratumoral and Peritumoral Lymphatic Density and Blood Vessel Density in Invasive Breast Carcinomas

We studied tumor lymphatic and vascular densities and lymphovascular invasion (LVI) as prognostic markers in 48 cases of invasive breast cancer treated with partial or total mastectomy and lymph node dissection. All cases were immunostained with D2-40 and CD31. Positively stained microvessels were counted in densely vascular/lymphatic foci (hot spots) at x400. The mean+/-SD peritumoral lymphatic microvessel density (LMD) was significantly higher than intratumoral LMD (9+/-7 vs 4+/-6; P< .01). There was a positive correlation of D2-40 LMD (peritumoral and intratumoral) and CD31 microvessel density counts with lymph node metastasis (r=0.35, 0.5, and 0.38), nuclear grade (r=0.36, 0.28, and 0.3), and stage (r=0.42, 0.56, and 0.49), respectively. Peritumoral and intratumoral D2-40 LMD correlated significantly with the presence of angiolymphatic invasion (detected by D2-40; r=0.54 and 0.54, respectively). D2-40 detected more LVI than H&E- and CD31-detectable vascular invasion (18/48, 5/48, 11/48, respectively). Increased D2-40 detected LVI, and high CD31 microvessel counts showed significant adverse effect on survival status.

Chemokine-mediated migration of melanoma cells towards lymphatics – a mechanism contributing to metastasis

The mechanisms that cause tumors such as melanomas to metastasize into peripheral lymphatic capillaries are poorly defined. Non-mutually-exclusive mechanisms are lymphatic endothelial cell (LEC) chemotaxis and proliferation in response to tumor cells (chemotaxis-lymphangiogenesis hypothesis) or LECs may secrete chemotactic agents that attract cancer cells (chemotactic metastasis hypothesis). Using migration assays, we found evidence supporting both hypotheses. Conditioned medium (CM) from metastatic malignant melanoma (MMM) cell lines attracted LEC migration, consistent with the lymphangiogenesis hypothesis. Conversely, CM from mixed endothelial cells or LECs, but not blood endothelial cells, attracted MMM cells but not non-metastatic melanoma cells, consistent with the chemotactic metastasis hypothesis. MMM cell lines expressed CCR7 receptors for the lymphatic chemokine CCL21 and CCL21 neutralizing antibodies prevented MMM chemotaxis in vitro. To test for chemotactic metastasis in vivo tumor cells were xenotransplanted into nude mice approximately 1 cm from an injected LEC depot. Two different MMM grew directionally towards the LECs, whereas non-metastatic melanomas did not. These observations support the hypothesis that MMM cells grow towards regions of high LEC density owing to chemotactic LEC secretions, including CCL21. This chemotactic metastasis may contribute to the close association between metastasizing tumor cells and peri-tumor lymphatic density and promote lymphatic invasion.

Dysadherin Expression in Head and Neck Squamous Cell Carcinoma

Dysadherin is a recently characterized cancer-associated cell membrane glycoprotein that has a crucial role to cell-cell adhesiveness. The aim of this study was to examine dysadherin expression in head and neck squamous cell carcinoma (HNSCC). A total of 108 tissue specimens of patients with HNSCC were examined using immunostaining for dysadherin, E-cadherin, and the specific lymphatic endothelium marker D2-40. We quantified dysadherin and E-cadherin expression, assessed intratumoral (ILD) and peritumoral lymphatic density (PLD), and examined the possible associations of all the above parameters with clinicopathologic features and outcome. Finally, we used double staining with dysadherin and D2-40 to examine the expression pattern of dysadherin simultaneously with the lymphovasculature environment of HNSCC. High dysadherin expression was correlated with higher clinical stage (chi2, P = 0.01), with the presence of lymph node metastasis at the time of diagnosis (chi2, P = 0.02), and with increased ILD (chi2, P = 0.001). We observed an impressive reverse association between increased dysadherin expression and decreased E-cadherin expression (chi2, P < 0.001). Surprisingly, dysadherin-positive cancer cells usually gathered around areas of high intratumoral lymphatic vessel concentration, surrounding and invading small intratumoral lymphatics. Higher clinical stage and increased dysadherin expression were found to be the only significant independent prognostic factors for overall survival (hazard ratio, 3.94; 95% confidence interval, 1.09-14.27 for clinical stage; hazard ratio, 3.92; 95% confidence interval, 1.46-10.51 for dysadherin). The loss of intercellular adhesiveness and increased dysadherin expression seems to be related to lymphangiogenesis in HNSCC, but this should be confirmed by additional studies. Dysadherin expression might be a promising prognostic marker for separation of patients at higher risk.

Evidence for lymphangiogenesis and its prognostic implications in head and neck squamous cell carcinoma

Lymph node metastasis is a frequent reason for adverse clinical outcome in many epithelial neoplasms, including head and neck squamous cell carcinoma. The mechanisms underlying the capability of epithelial neoplasms to metastasize via lymphatic vessels have not yet been fully elucidated. There is great debate about whether cancer cells can metastasize by expansion and invasion of pre-existing peritumoral lymphatics or by the formation and invasion of new lymphatics within tumours (lymphangiogenesis). In order to investigate this issue, we examined 81 tissue specimens from patients with head and neck squamous cell carcinoma, using immunostaining for the specific lymphatic endothelium marker podoplanin, and assessed intratumoral and peritumoral lymphatic density. We also quantified lymphatic invasion and examined the possible associations of all the above parameters with clinicopathological features and outcome. Finally, we used double staining with podoplanin and the cell proliferation marker Ki-67 in order to evaluate lymphangiogenesis. High intratumoral and peritumoral lymphatic density were both significantly associated with the presence of lymph node metastasis at the time of diagnosis (chi2 test, p < 0.001 and p = 0.007, respectively) and there was a significant correlation between high intratumoral lymphatic density and lymphatic invasion. Patients with higher intratumoral lymphatic density exhibited shorter overall survival (log rank p < 0.001) and this correlation remained significant after multivariate analysis (Cox p = 0.04), indicating that intratumoral lymphatic density is an independent prognostic factor for mortality. Peritumoral lymphatic density had no influence on outcome. Double staining revealed the existence of proliferating intratumoral lymphatics, in which tumour emboli were occasionally observed. These results indicate that lymphangiogenesis indeed occurs in head and neck squamous cell carcinoma; that newly formed vessels are targets of invasion by cancer cells; and that intratumoral lymphatic density might be used as a criterion to separate patients at higher risk of an adverse clinical outcome.