Novel therapeutics in low-grade serous ovarian cancer.

ABSTRACT

Low-grade serous ovarian cancer is a rare subtype of epithelial ovarian cancer clinically characterized by younger age at diagnosis, relative chemoresistance, and prolonged survival compared with its high-grade serous counterpart. It is molecularly characterized by estrogen and progesterone receptor positivity, aberrations in the MAPK (mitogen-activated protein kinase) pathway, and wild-type TP53 expression pattern. As research into low-grade serous ovarian cancer as a distinct entity has been able to accelerate independently, we have learned more about its unique pathogenesis, oncogenic drivers, and opportunities for novel therapeutics. In the primary setting, cytoreductive surgery in combination with platinum-based chemotherapy remain the standard of care. However, low-grade serous ovarian cancer has demonstrated relative chemoresistance in the primary and recurrent settings. Endocrine therapy is also commonly utilized in the maintenance and recurrent settings and is being evaluated in the adjuvant setting. Given the many similarities of low-grade serous ovarian cancer to luminal breast cancer, many recent studies have utilized similar therapeutic strategies including endocrine therapy combinations with CDK (cyclin-dependent kinase) 4/6 inhibitors. Additionally, recent trials have investigated combination therapies targeting the MAPK pathway, including MEK (mitogen-activated protein kinase kinase), BRAF (v-raf murine sarcoma viral oncogene homolog B1), FAK (focal adhesion kinase), and PI3K (phosphatidylinositol 3-kinase) inhibition. In this review, we will outline these novel therapeutic strategies for low-grade serous ovarian cancer.