Prognostic value of LYVE-1-positive lymphatic vessel in tongue squamous cell carcinomas

The density of lymphatic vessels in 52 cases of human tongue squamous cell carcinoma (TSCC) and normal portions was analyzed. TSCC specimens were immunostained with antibodies against lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) and podoplanin monoclonal antibody (D2-40). The significance of the LYVE-1-positive vessel density (LVD) was calculated in 6 topographic areas and investigated on the basis of specific clinical and histo-pathological parameters. LYVE-1 positivity was more evident in the muscular area than the submucosal area, while small D2-40-positive lymphatic vessels were not demonstrable in muscular endomysium. The LVD in peri-tumoral submucosal and peri-tumoral muscular areas was lower than in normal counterparts (p<0.01). LVD was higher in the tumor invasion front as compared to tumor-associated stroma (p<0.01). Low LVD in invasion front and peri-tumoral submucosal area was significantly related to regional lymph node metastasis (p<0.05 and p<0.01, respectively). The decrease of LYVE-1-positive lymphatic vessels in the invasion front and peri-tumoral submucosal area would seem to predict cervical lymph node metastasis in TSCC.