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Vol.57 No.6 contents | Japanese/English |
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- Original Article -
Clinicopathological Significance of Epithelial Mesenchymal Transition in Thymic Cancer
Yasushi Shintani1, Soichiro Funaki1, Tomohiro Kawamura1, Naoko Ose1, Ryu Kanzaki1, Masato Minami1, Eiichi Morii2, Meinoshin Okumura11Department of General Thoracic Surgery, 2Department of Pathology, Osaka University Graduate School of Medicine, Japan
Objectives. Epithelial mesenchymal transition (EMT) is a fundamental biological process during which epithelial cells change to a mesenchymal phenotype, which has a profound impact on cancer progression. It has been proposed that the increased expression of EMT markers, loss of epithelial markers such as E-cadherin, and altered expression of mesenchymal markers such as N-cadherin, referred to as cadherin switching, are associated with a poor prognosis in patients with cancer. We analyzed the expression of E-cadherin and N-cadherin in thymic cancer to determine their relationship to the clinicopathological factors and prognosis. Methods. We collected data from 31 patients with thymic cancer treated at our institution between 2000 and 2014. Immunohistochemistry was used to examine the expression of EMT markers, E-cadherin, and N-cadherin in tumor specimens. The correlation between EMT and the prognosis in patients with thymic cancer was also evaluated. Results. Surgical resection was extended to the surrounding organs in addition to thymectomy, including patients with a thymic tumor and those who underwent an anterior mediastinal lymphadenectomy. Twenty-six patients received R0 resection. As for the Masaoka staging, pathological findings revealed 1 patient with stage I, 1 with stage II, 20 with stage III, 1 with IVa, and 8 with IVb disease. The histological diagnosis was squamous cell carcinoma in 25, undifferentiated carcinoma in 4, and others in 2 patients. Immunohistochemical results showed a decreased expression of E-cadherin or the up-regulation of N-cadherin in surgically resected specimens from 15 patients with tumors classified as EMT marker-positive. The 5-year survival rate was 86% for all, 63% for EMT marker-positive cases, and 100% for EMT marker-negative cases. The survival of patients with EMT marker-positive tumors was significantly worse than in those with EMT marker-negative tumors. Conclusion. The EMT marker expression, such as cadherin switching, was detected in resected thymic cancer tumors. Our results indicated that EMT affects the degree of malignant potential of thymic cancer.
key words: Thymic cancer, Epithelial mesenchymal transition, Cadherin switch, Prognostic factor
Received: June 14, 2017
Accepted: August 17, 2017
JJLC 57 (6): 746-751, 2017
