Background and aims: The research reports indicate the effect of exercise as an important factor in the prevention of breast cancer. In the process of cancer development, the cytokines are playing the vital role as regulatory proteins. The aim of this study was to investigate the effect of a one-term moderate intense endurance exercise before tumor formation on serum concentration content of a cytokine, Interleukin-1 (IL-1) as well as life span in the breast cancer balb/c mouse model.

Methods: This research was an experimental project. 17 female BALB/c mice were randomly distributed into two groups of experimental Group (exercise+tumor) and control Group (rest+tumor). Prior to the tumor formation, the EG mice performed a daily session of
35-40 minutes endurance exercise protocol for 12 consecutive weeks and 5 days a week. The exercise intensity began with 15.4 meter per minutes in the first week and then it was gradually raised up to 23.8 meters per minutes during the last week. In order to induce cancer, one day after the end of the exercise protocol, all animals in both groups received subcutaneous injections of T4¹⁰ cell line. After the formation of cancerous tumor, the ELISA method applied to measure the serum content of IL-1 and the volum of tumor was measured by caliper.

Results: Comparing the 2 groups, a significant difference (P=0.001) between the average serum IL-1 content was observed and also the volume of tumor in mice suffered from cancer in experimental group was significant (P=0.003).

Conclusion: Moderate intense endurance exercise can play a preventive role in breast cancer causing reduction of the cancerous inflammation in the patients suffering from breast cancer.