Localization of high endothelial venules is important for the prognosis of patients with oral squamous cell carcinoma

Objectives: Surgery, chemotherapy, and radiation therapy are currently used for the treatment of malignant tumors, and immunotherapy has recently been established as the fourth method for treating cancer. Therefore, cancer cells and their surrounding microenvironments have been the focus of attention. High endothelial venules (HEVs) that mediate lymphocyte extravasation into lymphoid organs have been reported in cancerous tissues. However, the role of HEVs remains controversial. In this study, the clinical significance of HEVs in patients with oral squamous cell carcinoma (OSCC) was examined. Methods: Eighty-three patients with OSCC of the tongue who had surgery as initial treatment were included. HEVs and lymphocytes were immunohistochemically stained, and their numbers and localization were evaluated. Results: The prognosis significantly improved in patients with a high number of HEVs. Additionally, localization of HEVs to the tumor margins was associated with a good prognosis. Patients with localized infiltration of CD8-positive cells at the tumor margin had a significantly better prognosis, although no correlation was observed between the number of CD8-positive cells around the HEVs and the prognosis. Cox proportional hazards model revealed that TNM Stage, localization of HEVs, and localization of CD8-positive cells are prognostic factors affecting disease-free survival in patients with OSCC. Conclusions: The localization of HEVs and CD8-positive cells affect the prognosis of patients with OSCC and they are beneficial prognostic factors.