Pattern of metastasis related to clinicopathological features in curatively resected head and neck cancer

초록

Background Epithelial mesenchymal transition (EMT) means that the epithelial cells lose their properties of adhesion and polarization and gain properties of invasion and migration and has an important role in invasion and metastasis of tumor cells. EZH2 have an effect on EMT through regulating E‒cadherin expression. However, the exact role of EZH2 and its clinical significance in head and neck squamous cell carcinoma (HNSCC) are not yet known. We tried to examine EZH2 expression with clinic‒ pathological characteristics to clarify the role of the prognosis in HNSCC. Methods We obtained formalin‒fixed paraffin‒embedded tissues of 118 patients who received curative surgery for HNSCC. All patients received R0 resection. Six blocks of TMA were made for immunohistochemical study. Paraffin blocks of the tissue microarray were sectioned at a 4um thickness. The nuclear staining of EZH2 was evaluated semi‒quantitatively on the basis of staining intensity and distribution using the immunoreactive scores. Results Total 29 recurrences were observed. Among them, 17 patients showed local recurrence only, and 12 patients showed distant metastasis with or without local recurrence. We analyzed distinct patterns of metastasis according to protein expression profile. A significant association between high expression of EZH2 which is a kind of mesenchymal marker and the presence of distant progression was demonstrated (P =.026). In patients with node‒negative HNSCC, total 15 patients had recurrences. Among them, 7 patients had distant metastasis and all of these 7 patients exhibited EZH2 at the time of initial diagnosis. However, we did not find its correlation into overall survival. Conclusions EZH‒2, one of EMT‒associated protein expressed HNSCC was associated with more distant metastasis. It could be a useful marker for determination of additional treatment (e.g. adjuvant chemotherapy and/or radiotherapy) in cur