ICANCER RESEARCH55. 5693-5698. December 1. t995l ABSTRACT Few molecular genetic alterations have been identified in endometrial cancers that are associated with poor clinical outcome. Overexpression of HER-2/neu, transforming growth factor a, and p53 proteins have all been associated with poor prognosis in women with endometrial cancer. In this study, the level of HER-2lneu gene amplification and expression was characterized in 92 endometrial cancers. Fluorescence in situ hybridiza tion (FISH) was used to characterize HER-2/neu gene copy number, and immunohistochemistry was used to characterize expression. Forty-seven of the 90 (52%) endometrial cancers were characterized as showing moderate or high immunostaining. HER-2lneu gene amplification was detected in 17 ofSl (21%) cases. Immunohistochemical staining and FISH results were both available for 80 cases. Fourteen of these cases showed both moderate or high immunostaining and gene amplification. Clinical follow-up information was available for 76 women in this study. Women whose endometrial cancer exhibited HER-2/neu gene amplification by FISH had a shorter overall survival than women whose endometrial cancer lacked amplification (P = 0.018). Likewise, tumors with moderate or high HER-2lneu immunostaining were associated with a lower cumu lative overall survival than tumors with low immunostaining by log rank analysis (P < 0.0001). Multivariate analysis of survival rates revealed RER-2lneu overexpression to be an independent predictor of overall survival (P = 0.0163). Among those patients with HER-Zfneuoverexpres sion, adjuvant chemotherapy or radiation therapy was associated with an improved overall survival (P 0.039). However, among those women whose tumor lacked overexpression, overall survival was not improved by adjuvant treatment. INTRODUCTION Endometrial cancer is the most common cancer of the female genital tract in the United States, with approximately 33,000 new cases diagnosed annually (1). Relatively few studies have been per formed to identify molecular genetic alterations in endometrial can cers. Some proto-oncogenes and tumor suppressor genes have been reported to be altered. Activating point mutations in c-Ki-ras (2) appear to be an early event in tumorigenesis because the altered form of the gene is uniformly present in endometrial carcinoma, as well as in adjacent atypical hyperplasia (3). Missense single base substitutions have been observed in the p53 tumor suppressor gene of endometrial carcinomas (4). Increased expression of HER-2/neu oncoprotein (5— 12), transforming growth factor a protein (1 1), and macrophage colony-stimulating factor proto-oncogene mRNA (13) have also been described. Various chromosomal alterations including isochromo somy of 1q10; deletion of 6q2l—25 (14); and loss of heterozygosity for 3p, 9q, l0q, and Yip (15) suggest that tumor suppressor genes may Received 7/10/95; accepted 10/2/95. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. I Supported in part by National Cancer Institute Grants CA48780 and CA50589, American Cancer Society Grants lN-2l-29/003 and PDT-41 1, and the Molecular Core Laboratory Facilities of the General Clinical Research Centers (NIH National Center for Research Resources GCRC MOl RR-43). 2 To whom requests for reprints should be addressed, at Department of Pathology, HMR91O, UniversityofSouthernCaliforniaSchoolofMedicine, 2011ZonalAvenue, Los Angeles, CA 90033. be located at these sites. Recently, it was reported that genomic instability in the form of microsatellite instability also occurs in endometrial carcinoma, which may contribute to the transformed phenotype (16, 17). Molecular genetic alterations have not only been identified in endometrial carcinomas, but some of them are of poten tial prognostic utility. These include p53 (18), transforming growth factor a (11), and HER-2lneu proteins (9, 19), which have been associated with poor clinical outcome. The HER-2/neu proto-oncogene encodes a Mr 185,000 transmem brane tyrosine kinase receptor, the aberrant overexpression of which has been implicated in the induction of a malignant phenotype (20— 22). The molecular mechanism responsible for kinase activation is thought to involve receptor homodimerization or heterodimerization. It has been postulated that overexpression of HER-2/neu oncoprotein leads to autoactivation of the tyrosine kinase domain, activation of signal transduction pathways, and cellular transformation or cellular proliferation (23). HER-2/neu overexpression has been used to predict both disease-free and overall survival in patients with various cancers including those of breast, ovary, and salivary gland (24, 25). Twenty five to 30% of breast and ovarian cancers show HER-2/neu overex pression and/or amplification. Women whose tumors harbor these alterations, independent of other indicators of clinical outcome such as nodal involvement, have lower rates of 5-year disease-free and overall survival. Although several studies have examined the association of HER-2/neu overexpression with prognostic indicators such as clinical stage, histological type, grade, and differentiation markers, as well as clinical outcome in endometrial cancer patients (5—12),the results obtained from these studies are not in agreement with respect to clinical outcome (9, 11, 12, 19). Because the prognostic value of HER-2/neu is not established, we evaluated HER-2/neu gene ampli fication and overexpression in a series of endometrial cancers and compared the results with established prognostic markers and with overall survival. In addition, the response of the patients to adjuvant therapies was compared to HER-2/neu expression level of the endo metrial cancer. MATERIALS AND METHODS Patient Information. The research protocal for this investigation was reviewed and approved by the Institutional Research Board (Protocal No. 059251). Racial or ethnic group was identified as white in 43, as black in 8, and as “Hispanic― in 5 women. Racial origins of Hispanic patients were not specified. Age at the time ofdiagnosis ranged from 29 to 87 years, with a mean of 60 years. Clinical information including age, sex, date of diagnosis, stage of disease, treatment, presence of recurrent disease, date of death, and cause of death were recorded for 76 of the 92 cases. The remaining 16 cases did not contain enough information to assess the clinical outcome. Clinical follow-up ranged from 3 to 123 months, with a mean of 67 months. Two patients were treated with chemotherapy, and 30 patients were treated with radiation therapy. The laboratory analyses were performed masked to the clinical information (Table 1). Tumor Tissue. Frozen tumor tissue from 90 endometrial cancers was analyzed for HER-2/neu gene expression by immunohistochemistry, and 81 5693 Amplification and Overexpression of HER-2/neu (c-erbB2) in Endometrial Cancers: Correlation with Overall Survival1 Bahman Saffari, Lovell A. Jones, Adel El-Naggar, Juan C. Felix, Jay George, and Michael F. Press2 Department of Pathology (B. S., J. C. F., M. F. P.] and The Norris Comprehensive Cancer Center (M. F. P.J,University of Southern California School of Medicine, Los Angeles, California 90633: Departments of Gynecological Oncology IL A. J.] and Pathology (A. E-N.], M. D. Anderson Cancer Center, University of Texas, Houston, Texas 77030; and Division of Research and Development, Oncor, Inc., Gaithersburg, Maryland 20877 (J. G.] Research. on November 28, 2021. © 1995 American Association for Cancer cancerres.aacrjournals.org Downloaded from