Effects of Chemotherapy Alone and Chemotherapy Combined with Antioxidants in Dogs with Mammary Gland Carcinoma

Most anticancer drugs (epirubucin, adriamycin, bleomycin, vincristin, cyclophosphamide) exert their cytotoxic effect by free radicals-mediated mechanisms. The purpose of this study was to establish whether the antioxidants co-administered with epirubicin and cyclophosphamide reduce the adverse side effects of cytostatic chemotherapy without affecting their efficacy in dogs with spontaneous mammary gland carcinomas. Studies were performed in 14 bitches aged 6–14 years, weighing 4–29 kg, with histologically confirmed mammary gland carcinoma. Ten days after the surgical removal of the tumour, animals were divided into two groups: group I, treated with epirubicin and cyclophosphamide alone and group II, treated with a combination of same anticancer drugs and antioxidants (vitamins C, E, and A). It was concluded that the inclusion of antioxidants as adjuvant to the standard chemotherapy protocol resulted in less adverse effects without reducing the efficacy of cytostatics and improved patients' tolerance to treatment.