Molecular characterization of ovarian cancer by gene-expression profiling

Ovarian cancer is the second most common gynecologic malignancy, and represents the fifth most common cause of cancer death in women in the United States. The age at diagnosis, extent of disease, success of primary surgery, and the histopathological features of the tumor are important prognostic markers. Epithelial ovarian carcinomas are classified into four major categories: serous, mucinous, endometrioid, and clear cell. Each subtypes of ovarian carcinoma are known to have different clinical characteristics and biological behaviour and response to chemotherapy. Molecular studies have supported for the notion that the different histological types of ovarian cancer likely represent histopathologically, genetically, and biologically distinct diseases. Microarray-based profiling technologies have provided an opportunity to simultaneously examine the relationship between thousands of genes and clinical phenotypes. In this review, we will summarise the current gene-expression profiles that address the classification of ovarian cancer into molecular subtypes with different outcomes.