Author(s): TASCIOGULLARINDAN, T., IANC, R., BRIAULT, E., DELRIEU, L., MAIRE, A., GOUEZ, M., TRÉDAN, O., FERVERS, B., PÉROL, O., PIALOUX, V., Institution: LYON 1 CLAUDE BERNARD UNIVERSITY, Country: FRANCE, Abstract-ID: 2179

INTRODUCTION:
Breast cancer is the most common type of cancer in women, with metastatic breast cancer (MBC) having a low 5-year survival rate of 32 %. Oxidative stress, defined as an imbalance between Reactive Oxygen Species (ROS) production and antioxidant defense mechanisms, is a key factor in cancer progression. Physical activity (PA) has emerged as a supportive intervention in oncology, with post-diagnostic chronic PA associated with improved survival and reduced disease progression in several cancers, potentially through enhanced antioxidant defenses. However, these mechanisms remain unexplored in MBC. This study aimed to examine the effects of a 6-month structured PA program on oxidative stress biomarkers in women with MBC.
METHODS:
As part of a randomised controlled trial (ABLE 2), 120 women (age: 55.6 +/- 10.8, BMI at baseline: 25.2 +/- 5.25 kg/m2) with histologically confirmed MBC were assigned to either a home-based PA intervention or control group. Patients in the control group (n=60) received general PA recommendations, whereas patients in the intervention group (n=60) were equipped with an activity tracker (Withings Steel) for 6 months to monitor their activity. Patients in intervention group received personalized step goals based on baseline walking test, ranging from 2 500 to 10 000 steps/day. Intermediate monthly goals were adjusted according to difficulty in achieving previous month’s step target. Serum biomarkers of oxidative stress AOPP, MDA, MPO, SOD, CAT, GPX, and FRAP were assessed at baseline and at 3, 6, and 12 months. The data was analyzed using a two-way ANOVA with repeated measures. Together these seven markers allowed us to quantify both the burden of oxidative damage and the capacity of plasma antioxidant defences in our metastatic breast-cancer cohort.
RESULTS:
The PA group showed significant reductions across time in AOPP (P < 0.01), MDA (P <0.05), and MPO (P <0.05) whereas control group did not show any change. No significant changes in antioxidant enzyme capacity (SOD, CAT, GPX, FRAP) was detected regardless of group or time. Interestingly, clinical data showed a decrease in BMI of the intervention group, with an increase for the control group. These findings suggest that PA likely reduced oxidative stress primarily through decreased ROS production rather than enhanced antioxidant defense as it was previously shown in other metabolic and cardiovascular disease rehab programs. This lower ROS generation could result from the decrease of BMI after exercise intervention.
CONCLUSION:
These results suggesting that regular PA attenuates ROS generation in women with MBC, supports the role of exercise as a supportive strategy in cancer treatments by improving redox homeostasis.