Increased Expression of EZH2 in Merkel Cell Carcinoma Is Associated with Disease Progression and Poorer Prognosis

Publication date: Available online 21 July 2017
Source:Human Pathology
Author(s): Kelly L. Harms, Heather Chubb, Lili Zhao, Douglas R. Fullen, Christopher K. Bichakjian, Timothy M. Johnson, Shannon Carskadon, Nallasivam Palanisamy, Paul W. Harms
Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that affects tumorigenesis by epigenetic gene silencing. Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine carcinoma that has a high risk of disease progression with nodal and distant metastases. Here, we evaluated EZH2 expression by immunohistochemistry in a cohort of 85 MCC tumors (29 primary tumors, 41 lymph node metastases, 13 in-transit metastases, and 2 distant metastases) with clinical follow-up. We show strong/moderate EZH2 expression in 54% of tumors. Importantly, weak expression of EZH2 in the primary tumor, but not nodal metastases, correlated with improved prognosis compared to moderate/strong EZH2 expression (5-year MCC-specific survival of 68% versus 22%, respectively, P=.024). In addition, EZH2 was expressed at higher levels in nodal metastases compared to primary tumors (P=.005). Our data demonstrate that EZH2 has prognostic value and may play an oncogenic role in MCC.



http://ift.tt/2vtaGw3