[The molecular biology of epithelial ovarian cancer]

Epithelial ovarian cancer frequently presents at an advanced stage where the cornerstone of management remains surgery and platinum-based chemotherapy. Unfortunately, despite sometimes dramatic initial responses, advanced ovarian cancer almost invariably relapses. Little progress has been made in the identification of effective targeted-therapies for ovarian cancer. The majority of clinical trials investigating novel agents have been negative and the only approved targeted-therapy is bevacizumab, for which reliable predictive biomarkers still elude us. Ovarian cancer is treated as a uniform disease. Yet, biological studies have highlighted the heterogeneity of this malignancy with marked differences in histology, oncogenesis, prognosis, chemo-responsiveness, and molecular profile. Recent high throughput molecular analyses have identified a huge number of genomic/phenotypic alterations. Broadly speaking, high grade serous carcinomas (type II) display significant genomic instability and numerous amplifications and losses; low grade (type I) tumors are genomically stable but display frequent mutations. Importantly, many of these genomic alterations relate to known oncogenes for which targeted-therapies are available or in development. There is today a real potential for personalized medicine in ovarian cancer. We will review the current literature regarding the molecular characterization of epithelial ovarian cancer and discuss the biological rationale for a number of targeted strategies. In order to translate these biological advances into meaningful clinical improvements for our patients, it is imperative to incorporate translational research in ovarian cancer trials, a number of strategies will be proposed such as the acquisition of quality tumor samples, including sequential pre- and post-treatment biopsies, the potential of liquid biopsies, and novel trial designs more adapted to the molecular era of ovarian cancer research.