Metronomic chemotherapy: Back to the future!

Angiogenesis is crucial for the growth of cancer. As such, it has become an established target to fight cancer. Metronomic chemotherapy-the chronic administration of chemotherapy at relatively low, minimally toxic doses on a frequent schedule of administration, at close regular intervals, with no prolonged drug-free breaks-is a potential approach to control advanced cancer disease. It is thought to work primarily through antiangiogenic mechanisms and has the property to kill resistant cancer cells and/or to inhibit tumor growth while significantly reducing undesirable toxic side effects. Here, we will discuss potential mechanisms of action of metronomic chemotherapy and briefly review the data regarding the clinical experience with this kind of anticancer treatment. Based on recent insights in the various mechanisms of action, we will try to predict the potential new developments of metronomic chemotherapy in oncology.