Comparing the Effects of 4 and 12 Weeks of Aerobic Training on Tumor Volume in Female Mice with Breast Cancer

Introduction: Tumor size is a contributing factor in cancer prognosis. On the other hand, regular exercise may play an important role in inhibiting tumor growth in breast cancer. Because of the key role of tumor volume in tumor metastasis, the aim of the present study was to compare the effects of a 4-week and a 12-week aerobic training on tumor volume in female mice with breast cancer. Methods: Forty female BALB/c mice (4-5 weeks old weighing 18 ± 2g) were randomly divided into the following 5 groups of 8 after cancer induction: primary prevention group, secondary prevention group, treatment, exercise, and cancer control. Aerobic exercise was performed for 4 weeks at different stages (prevention, during treatment, and after cancer) at an intensity equal to 40% to 50% of the maximal oxygen consumption. The exercise group performed aerobic exercise for 40 minutes at 18 m/min at a zero-degree incline 5 times a week for 12 weeks. At the end of the training intervention period, all mice were sacrificed and tumor volume was measured using a digital caliper. Data were analyzed using the ANOVA test on SPSS v.22. Results: After 4 weeks of exercise intervention, a significant decrease in tumor volume was observed in the primary prevention and control groups (P = 0.001), and after 12 weeks of aerobic training, a decrease in tumor volume was observed in the exercise and control groups (P = 0.007). However, there was no significant difference in the other groups. Conclusion: Moderate-intensity aerobic exercise can be used as an effective treatment method to reduce the volume of breast tumors. However, more research is needed to reach definitive results.