Advances in Ovarian Cancer Treatment Beyond PARP Inhibitors

Ovarian cancer has become the largest cause of gynaecological cancer-related mortality. It is typically diagnosed at a late stage and has no effective screening strategy. Ovarian cancer is a highly heterogeneous disease that can be subdivided into several molecular subsets. As a result of a greater understanding of molecular pathways involved in carcinogenesis and tumor growth, targeted agents have been approved or are in several stages of development. Poly(ADP-ribose) polymerase (PARP) inhibitors and the anti-vascular endothelial growth factor (VEGF)-A antibodies are two types of approved and most effective targeted drugs for ovarian cancer at present. With the success of bevacizumab, tyrosine kinase inhibitors which could target alternate angiogenic pathways are being studied. Furthermore, many treatments targeting the PI3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways, are being developed or are already in clinical studies. MicroRNAs have also become novel biomarkers for the therapy and clinical diagnosis of ovarian cancer. This manuscript reviews the molecular, preclinical and clinical evidence supporting the targeting of growth-dependent pathways in ovarian cancer and assesses current data related to targeted treatments beyond PARP inhibitors.