RT Journal Article SR Electronic T1 The Impact of Exercise Training on Breast Cancer JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 249 OP 254 VO 32 IS 2 A1 KATARZYNA SIEWIERSKA A1 IWONA MALICKA A1 CHRISTOPHER KOBIERZYCKI A1 URSZULA PASLAWSKA A1 MAREK CEGIELSKI A1 JEDRZEJ GRZEGRZOLKA A1 ALEKSANDRA PIOTROWSKA A1 MARZENNA PODHORSKA-OKOLOW A1 PIOTR DZIEGIEL A1 MAREK WOZNIEWSKI YR 2018 UL http://iv.iiarjournals.org/content/32/2/249.abstract AB Background/Aim: Physical exercise is increasingly considered by many authors to be a factor reducing the risk of cancer development and premature cancer-related death. Data indicate higher cure rates and longer times of survival in cancer patients who regularly exercise. Materials and Methods: A total of 50 female Sprague-Dawley rats were used in the experiment. Animals at 1 month of age were intraperitoneally injected with N-methyl-N-nitrosourea. Three months following drug administration, rats underwent supervised physical training. The animals were divided into four groups: control untrained group and 3 groups trained with different intensities – i.e. low, moderate and high. Routine histopathological examination of tumors was performed and mitotic activity was assessed by immunohistochemical expression of the Ki-67 antigen. Results: Ki-67 antigen expression was observed in all analyzed tumors. The increase in Ki-67 antigen expression correlated positively with the increase in training intensity. Conclusion: It can be assumed that low-intensity physical training is safe for patients with breast cancer. However, moderate- and high-intensity training may induce tumor cell proliferation worsening patients' prognosis.