Human epidermal growth factor receptor-2 overexpression and amplification in metastatic and recurrent high grade or type 2 endometrial carcinomas

Abstract

Rina Kato,1 Kiyoshi Hasegawa,1 Risa Ishii,1 Akiko Owaki,1 Yutaka Torii,1 Shuko Oe,1 Hiroshi Hirasawa,2 Yoichi Kobayashi,3 Yasuhiro Udagawa1 1Department of Obstetrics and Gynecology, Fujita Health University School of Medicine, Toyoake, Japan; 2Department of Pathology, Fujita Health University School of Medicine, Toyoake, Japan; 3Department of Obstetrics and Gynecology, Kyorin University School of Medicine, Mitaka, Japan Introduction: Human epidermal growth factor receptor (HER)-2 overexpression or gene amplification is more common in high-grade or type 2 endometrial carcinomas. We assessed the discordance of HER-2 expression between primary and metastatic or recurrent endometrial carcinomas. Materials and methods: Thirty-six primary, along with 14 metastatic and five recurrent tumors (matched to primaries), pathologically confirmed as high-grade or type 2 endometrial carcinomas, were submitted for immunohistochemistry (IHC) for HER-2. Fluorescence in situ hybridization was performed when the tumors showed HER-2 overexpression (≥2+ IHC score). The results of the IHC and fluorescence in situ hybridization assays were compared between the primary and metastatic or recurrent tumors. The relationships between HER-2 expression and clinicopathological factors or prognosis were investigated. Results: HER-2 overexpression and HER-2 amplification (a ratio of HER-2 copies to chromosome 17 [CEP17] copies ≥2.2) were detected in 33.3% (twelve of 36 patients) and 5.6% (two of 36 patients) of primary tumors, respectively. HER-2 overexpression was not associated with clinicopathological factors or prognosis. In 19 tumor specimens obtained from metastatic or recurrent tumors, HER-2 overexpression and HER-2 amplification were detected in 57.9% (eleven patients) and 15.8% (three patients), respectively. HER-2 overexpression tended to predict a worse prognosis. Conclusion: HER-2 expression in metastatic or recurrent tumors was more frequent than in matched primary high-grade or type 2 endometrial carcinomas. Trastuzumab in combination with cytotoxic chemotherapy may represent an alternative therapeutic option for these tumors. Keywords: endometrial carcinoma, high grade, type 2, HER-2, metastatic or recurrent tumors