Intratumoral Lymphatic Density Research Articles

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.

Lymphatic vessel density is significantly increased in melanoma

Melanoma is well known for its ability to involve regional lymph nodes in the early stage. However, the presence of lymphangiogenesis in melanoma is still controversial due to lack of lymphatic-specific markers. The purpose of this study was to determine the intra- and peritumoral lymphatic vessel density (LVD) using a novel lymphatic vessel-specific marker D2-40 and compare it to general vessel density (GVD) as determined by CD31 immunostaining in a series of melanocytic lesions. The intra- and peritumoral GVD and LVD were examined by immunohistochemistry using D2-40 and CD31 antibodies in a series of melanocytic lesions. We found significantly higher intratumoral LVD in melanomas as compared to either common acquired or dysplastic nevi (p < 0.01). Although peritumoral LVD in melanoma and malignant melanoma in situ was higher compared to nevi, the difference did not reach statistical significance (p = 0.059). There was no significant difference in GVD among the various groups of melanocytic lesions. Our results show that intratumoral LVD is significantly increased in melanomas compared to benign nevi. The higher intratumoral lymphatic density in invasive melanomas suggests that melanoma cells might promote lymphangiogenesis. In addition, assessment of intratumoral LVD may be potentially useful in the differential diagnosis of melanocytic lesions.