Roles of epithelial-mesenchymal transition in squamous cell carcinoma of the temporal bone.

OBJECTIVES The authors recently demonstrated that extensive bone erosion correlated with a worse prognosis of the squamous cell carcinoma (SCC) of the temporal bone. The present objective was to investigate the expressions and the roles of epithelial-mesenchymal transition (EMT) in SCC of the temporal bone. STUDY DESIGN Retrospective patient file review and immunohistochemical study of tissues of patients with SCC of the temporal bone. PATIENTS The authors examined the expressions of vimentin in 16 patients with SCC of the temporal bone by immunohistochemical analysis. RESULTS As expected, vimentin was expressed on SCC of the temporal bone. We regard the patient who has vimentin-positive cells as EMT-positive patient because gain of vimentin is a hallmark in the EMT reported in several types of cancer. EMT positive tumors significantly correlated with extensive bone erosion, and extensive bone erosion correlated with a worse prognosis of the SCC of the temporal bone. CONCLUSION The study results suggest that EMT in tumor cells becomes an important indicator of poor prognosis in SCC of the temporal bone.