New strategies in endometrial cancer: targeting the PI3K/mTOR pathway--the devil is in the details

Endometrial cancer is the most common gynecologic malignancy in the developed world and affects approximately 40,000 women in the United States each year. The phosphoinositide 3-kinase (PI3K) signaling pathway regulates key aspects of cancer biology including glucose uptake and metabolism, cellular growth, and survival. Endometrial cancers harbor the highest rates of PI3K pathway alterations reported to date. The PI3K pathway is highly druggable and several classes of agents are in clinical development including rapalogs, pan-PI3K inhibitors, PI3K isoform-specific inhibitors, dual PI3K/mTOR catalytic inhibitors, mTOR-specific catalytic inhibitors, and AKT inhibitors. It has been 10 years since the initiation of the first studies of rapalogs as anticancer agents. There are more than 20 registered clinical trials of PI3K/mTOR inhibitors as single agents or in therapeutic combinations for the treatment of endometrial cancers. What have we learned from the completed studies? What can we expect to learn from ongoing studies? What should we anticipate moving forward? Clin Cancer Res; 19(19); 5264-74. ©2013 AACR.