Exercise-induced Effects On Physical Performance And Growth Factors Levels In Breast Cancer Patients Undergoing Chemotherapy

Breast cancer (BCa) patients subjected to chemotherapy deal with various side effects, such as cardiotoxicity and sarcopenia, which deteriorate patients’ functional ability and threaten their survival. Moreover, several studies have linked high serum levels of growth factors in BCa patients with worse overall survival and disease prognosis. Exercise has been increasingly incorporated in therapeutic strategies as it mitigates some of the cancer- and treatment-related side effects. PURPOSE: This study investigated the effects of exercise on physical performance and systemic IGF-1 and TGF-beta levels in BCa patients during chemotherapy. METHODS: Ten female BCa patients receiving adjuvant chemotherapy (age: 38.8 ± 1.4 yrs, BMI: 24.2 ± 1.4 kg/m2) were participated in a 3-month supervised, individualized exercise training program 3 times per week, combining aerobic and resistance exercise. Every 4 weeks, patients’ aerobic capacity (VO2max) was evaluated with the «Rockport 1-mile walk test», while «Sit to Stand-60 sec», «Sit Ups-60 sec» and «handgrip» tests were used to evaluate their muscular performance. Besides, blood samples were collected every 6 weeks to analyze IGF-1 and TGF-beta levels by ELISA. RESULTS: At the end of the exercise intervention, aerobic capacity was increased by 11 ± 6% (p < 0.05), while «Sit to Stand» and «Sit Ups» performance by 27 ± 10% (p < 0.05) and 52 ± 14% (p < 0.001), respectively. Handgrip strength was improved in the arm of the non-operated side (13 ± 6%, p < 0.05), while in the arm of the mastectomy side there was also a trend to increase (13 ± 4%, p > 0.05). Plasma levels of IGF-1 were reduced from 2516 ± 1163 pg/ml at baseline to 612 ± 184 pg/ml after 12 weeks of training (p < 0.05), while levels of TGF-beta were decreased from 2629 ± 1052 pg/ml at baseline to 1454 ± 764 pg/ml post-training, however without reaching statistical significance (p > 0.05). CONCLUSIONS: Our findings revealed that the 3-month exercise intervention improved the aerobic capacity and muscular performance of upper and lower extremities in BCa patients during adjuvant chemotherapy, while decreased circulating IGF-1 levels. These findings suggest that exercise training can reduce treatment-induced side effects and regulate systemic growth factors in BCa patients, potentially influencing disease progression and prognosis.