Her-2/neu expression and amplification in early stage ovarian surface epithelial neoplasms.

OBJECTIVE: The aim of this study is to examine Her-2/neu gene amplification and protein overexpression in a spectrum of ovarian neoplasms using both immunohistochemical (IHC) and fluorescence in situ hybridization (FISH) techniques that are FDA approved. This study is focused on early stage tumors including both carcinomas and borderline tumors.

METHODS: FDA-approved IHC and FISH for Her-2/neu were performed on formalin-fixed, paraffin-embedded tissue from 79 ovarian neoplasms representing a broad spectrum of tumor types as well as four normal ovaries. All tumors were either stage I or stage II. Tumor and normal tissue were studied collectively using a tissue microarray (TMA). HercepTest (DAKO) and PathVysion Her-2/neu probe kit (Vysis Inc.) were used for IHC and FISH analysis.

RESULTS: FISH analysis of serous carcinomas demonstrated Her-2/neu gene amplification in 3 (18%) of 17 cases. Two of three cases showing Her-2/neu gene amplification were scored 1+ using IHC, while the remaining case was scored as 0. Analysis of endometrioid carcinomas demonstrated Her-2/neu amplification using FISH in 1 of 10 (10%) cases. IHC in this case was scored 2+ (positive). None of the remaining 44 tumors, including clear cell carcinoma (n = 12), transitional cell carcinoma (n = 1), mixed epithelial carcinoma (n = 7), carcinoma not otherwise specified (n = 1), and 31 borderline tumors (mucinous, n = 17; endometrioid, n = 7; serous, n = 7), showed Her-2/neu gene amplification or protein overexpression. Normal ovaries were negative as well.

CONCLUSIONS: Amplification of Her-2/neu in early stage ovarian neoplasms is infrequent, 6.7% overall. Due to the limited number of informative cases, we were unable to determine the clinical significance of Her-2/neu amplification in this study. Her-2/neu amplification was restricted to carcinomas and was not encountered in ovarian borderline tumors.