Therapeutic efficacy of metronomic chemotherapy with cyclophosphamide and doxorubicin on murine mammary adenocarcinomas

Metronomic chemotherapy (MCT) involves the chronic administration of doses of chemotherapy drugs that are below the maximum tolerated dose (MTD), at frequent and regular intervals, without extended rest periods [1]. It aims to achieve a balance between efficacy in tumor killing and lack of toxicity. The inhibition of angiogenesis would explain its therapeutic effect [2, 3]. We have demonstrated the antitumor efficacy of MCT with cyclophosphamide (Cy) as a single drug [4] and in combination with celecoxib on mice mammary adenocarcinomas (MA) [5]. Considering the high incidence of mammary tumors in humans, in this study, we analyze the therapeutic efficacy, toxicity and mechanism/s of action of MCT combining Cy and doxorubicin (Dox), in mouse MA tumor-models.