metronomic chemotherapy: connecting theoretical insights to practical use in canine cancer therapy

The prevalence of neoplastic diseases in companion animals has been increasing over the past few years. metronomic chemotherapy (mc), also known as low-dose continuous chemotherapy, is characterized by the oral administration of chemotherapeutic agents in low doses on a continuous schedule, without prolonged drug-free breaks. this approach was initially designed to overcome the development of resistance to chemotherapeutic agents by inhibiting tumor angiogenesis, however, additional mechanisms of action have been uncovered over the past two decades. the aim of this study is to investigate the clinical application of metronomic chemotherapy in canine cancer. this study is a review study by searching scientific databases such as scopus, pubmed, and embase from 2016 to 2024 by using the keywords chemotherapy, metronomic chemotherapy, canine oncology, canine mammary tumors, 71 articles related to inclusion criteria were extracted and then analyzed. cyclophosphamide-based mc has become increasingly recognized for the treatment of various neoplastic diseases in dogs. its uniqueness lies in its mode of action؛ instead of the direct cytotoxic effect observed with maximum tolerated dose (mtd) chemotherapy, mc has a number of mechanisms of action to kill cancer cells. the most important is the antiangiogenic effect, however, it also exerts immunomodulatory effects, may target cancer stem cells, and potentially induce a state of tumor dormancy. metronomic chemotherapy can be used as a first-line treatment or in combination with other anticancer therapies and has beneficial effects on several tumor types, particularly various sarcomas. looking forward, the landscape of veterinary oncology is set to evolve significantly, with ongoing research aimed at refining mc protocols to identify the most effective dosing strategies. in addition, the integration of mc into new therapeutic protocols, including immunotherapy and targeted therapies, opens the possibility for personalized oncological care, contributing to better outcomes.