Ovarian clear cell carcinoma (CCC) is a unique type of ovarian cancer characterized by distinct clinicopathological and molecular features. CCC is considered to be a highly malignant disease because it is resistant to conventional chemotherapy, and when presented at advanced stages, it has a dismal overall survival. Identifying and characterizing biomarkers associated with its malignant behavior is fundamental toward elucidating the mechanisms underlying its aggressive phenotype. In this study, we performed immunohistochemical analysis on 89 CCCs to assess their expression of Rsf-1 (HBXAP), a chromatin-remodeling gene frequently amplified and overexpressed in several types of human cancer. We found that 73 (82%) of the 89 CCCs expressed Rsf-1 and most importantly, there was a statistically significant correlation between Rsf-1 immunostaining intensity and the 2 disease parameters: advanced stage (P=0.008) and status of retroperitoneal lymph node metastasis (P=0.023). However, there was no correlation between Rsf-1 expression and patient age, peritoneal tumor dissemination, or overall survival. In conclusion, a higher expression level of Rsf-1 is associated with advanced clinical stage and lymph node metastasis in CCC. Our data suggest that Rsf-1 participates in tumor progression in CCC, and indicates that the contribution of Rsf-1 to disease aggressiveness deserves further study.
Department of Pathology (D.M., X.C., B.G., I-M.S.)
Departments of Gynecology and Obstetrics and Oncology (D.M., T-L.W., I-M.S.), Johns Hopkins Medical Institutions, Baltimore, Maryland
Department of Pathology (D.M., M.F.)
Department of Obstetrics and Gynecology (S.N., T.Y., Y.T.), Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
This study was supported by NIH/NCI Grant CA129080 and the International Training Program from the Japan Society for the Promotion of Science.
Address correspondence and reprint requests to Ie-Ming Shih, MD, PhD, Johns Hopkins Medical Institutions, 1550 Orleans street, CRB-2, room: 305, Baltimore, Maryland 21231. e-mail: firstname.lastname@example.org