Abstract 1862: NY-ESO-1 and clinicopathological features in ovarian cancer

Ovarian cancer ranks fifth in cancer deaths among women and the American Cancer Society estimates that in the US about 15,460 women will die from this disease in 2011. NY-ESO-1 is an 18 kDa member of the cancer/testis 6 antigen family which is thought to play a role in germ cell differentiation. In healthy adults, NY-ESO-1 is restricted to the testis. NY-ESO-1 expression has been found in various malignant neoplasms, including melanomas, neuroblastomas, soft tissue sarcomas, and carcinomas from the breast and endometrium. To further delineate the role of NY-ESO-1 in epithelial ovarian cancer, we constructed a tissue microarray of archived formalin-fixed paraffin-embedded paired tumor and normal control specimens from ovarian cancer patients. NY-ESO-1 expression was correlated with clinicopathologic features and overall survival. Specimens were collected from 242 patients who underwent cytoreductive surgery for ovarian cancer between 1989 and 2009. Immunohistochemical staining was performed with mouse monoclonal antibody clone E978 specific for NY-ESO-1. Stained slides were digitized with the Aperio ScanScope XT and images were analyzed using DEFINENS Tissue Studio software. Histological scores (H-scores) based on intensity of NY-ESO-1 staining and percent positive cells were calculated for all specimens. Positive NY-ESO-1 expression was found in 21% of papillary serous carcinomas, 18% of endometrioid carcinomas, and 20% of clear cell carcinomas. Ovarian cancer tissue had significantly higher H-scores compared to normal tissue controls from the same patients. H-scores increased with increasing FIGO stage and grade of the tumors. Caucasians had higher H-scores compared to African Americans and Asians. H-scores did not correlate with overall survival. Similarly, no differences in overall survival based on NY-ESO-1 expression levels were detected when patients were stratified by their histologic subtype. In conclusion, NY-ESO-1 is expressed in all histologic subtypes of epithelial ovarian cancer but not in normal tissues, therefore making it an ideal candidate for the development of targeted therapeutic approaches in ovarian cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1862. doi:1538-7445.AM2012-1862