Metronomic Chemotherapy: When Less May Be More

The use of low dose continuous schedules of chemotherapy (i.e. metronomic chemotherapy), delivered at lower doses by necessity compared to traditional dosing schemes, has become an increasingly popular addition to patient management in veterinary medical oncology. While the concept itself is not new, as low dose, maintenance chemotherapy protocols have been important components of treatment for certain cancers (such as acute lymphoblastic leukemia) for decades, research into the reasons for potential benefit have evolved as more knowledge is acquired in the areas of cancer biology and the tumour microenvironment. There is still much to be learned, however the low cost, ease of administration, and acceptable toxicity profiles, make metronomic chemotherapy protocols both attractive and suitable to veterinary applications. Preliminary clinical trial results have now been reported in both human and veterinary medicine, and further, more powerful studies are ongoing.