Characterization and prognostic value of lymphatic vessels in an oral tongue squamous cell carcinoma cohort

Abstract

Tumor lymphangiogenesis increases the area of interaction between lymphatic vessels and tumor cells, and may thereby facilitate metastases. In oral cancer high lymphatic vessel density (LVD) and large lymphatic vessel area (LVA) have been associated with more aggressive tumors, but results from different studies are not conclusive. The aim of this study was to assess the association of tumor-associated LVD and LVA with clinical-pathological data, including patient survival, in a homogenous cohort of oral tongue squamous cell carcinoma (OTSCC) patients. Formalin-fixed, paraffin-embedded tumour samples from 125 OTSCC patients were immunohistochemically stained with the D2-40 antibody to recognize lymphatic vessels. The mean LVD and the mean LVA were analysed in five hotspots per tumour sample and compared to clinical-pathological data as well as 5-year disease-specific survival (DSS). Neither LVD nor LVA were significantly associated with the clinical-pathological variables or 5-year DSS in our patient cohort. In univariate analyses, the N status, tumour stage, tumour differentiation as well as lymphocyte infiltration were the only significant predictors for patient outcome (p<0.001, p<0.001, p<0.001 and p=0.043 respectively). In multivariate analyses, only the N status and tumour differentiation were independent prognostic factors. LVD and LVA are not indicative of 5-year DSS in our OTSCC cohort. More studies on the immunoregulatory, location-dependent role of lymphatic vessels in large, homogeneous OTSCC patient cohorts are needed.