Study of Oxidant/Antioxidant Profile in Dogs with Mammary Cancer Undergoing Mastectomy, During the Peri-Operative Period

In cancer cases, any imbalance between Reactive Oxygen Species (ROS) production and host antioxidant capacity (oxidative stress), during the immediate post-operative period, is involved in cancer cell dissemination (micro-metastases). Surgical trauma is considered the main cause for ROS production during that period. Increased oxidative stress has been found in dogs with mammary neoplasms. Our objective was to investigate the blood oxidant/antioxidant profile in bitches with mammary cancer, during the peri-operative period, hypothesizing that oxidative stress would be further increased after mastectomy. Twelve bitches with mammary cancer and no distant metastases, with a comparable extent of surgical wound and receiving the same anesthetic protocol, were included. Their serum oxidant/antioxidant profile was evaluated chromatometrically using the d-ROMs (Reactive Oxygen Metabolite-derived compounds) and the BAP (biological antioxidant potential) tests, on the 1st day (before/after surgery), and on the 2nd, 3rd and 10th days post-operatively. The ratio of d-ROMs and BAP values (oxidative stress index; OSI) was also calculated. Statistically significant differences (increases) were found only in d-ROMS on the second and third post-operative day compared to the first day (before surgery) of measurement (<i>p</i> = 0.007 and <i>p</i> = 0.002, respectively). Our findings indicate a post-surgical overproduction of ROS and therefore an oxidative stress increase potentially affecting patient outcome.