Exercise may lower risk of cancer therapy-related cardiac dysfunction (CTRCD) in early-stage breast cancer patients undergoing targeted therapy. Results from a small prospective study

Background Anticancer molecular targeted therapies are associated with a better outcome regarding oncologic disease, but often with adverse effects on the heart. High troponin levels in patients receiving antiHER2 antibodies associate with a higher rate of subsequent cardiac events. Despite significant progress, preventive strategies for cancer therapy-related cardiac dysfunction (CTRCD) are still under investigation. Aim To quantify the impact of exercise training on the risk of early CTRCD in HER2+ breast cancer patients undergoing antiHER2 therapy. Methods 54 females (mean age 51 ± 1.2 years) with HER2+ early-stage breast cancer, starting trastuzumab/pertuzumab in adjuvant setting, consented to be randomized: 27 with standard-of-care and exercise training (intervention group) vs. 27 with standard-of-care only (controls). Training consisted of 10 weeks supervised group aerobic exercises (20 minutes intervals, 2 times aweek, 65-75% of maximal heart rate goal). Patients were followed-up 6 months, by measuring hs-T troponin at baseline, monthly and at the end of study period (local lab cut-off value 14 pg/ml). Subjects were matched according to variables (age, antiHER2 dosage regimen, baseline heart risk, concomitant medications). Results All patients fulfilled the follow-up period, with no adverse cardiac event registered in the studied groups. Mean baseline hs-T troponin was similar in the studied groups (6.2 ± 0.9 pg/ml in the control group; 6.5 ± 1.1 pg/ml in the training group; p=0.27). After completion of follow-up, mean hs-T troponin was 17.3 ± 2.73 pg/ml in the control group vs. 10.9 ± 1.89 pg/ml, showing a significant difference favorable to the training group (p=0.00036). At the end of the follow-up, 3 patients in the control group had a slight increase over cut-off troponin T-hs, compared to only 1 in the training group (11.1% vs. 3.7%). Conclusion In our study, a supervised mild-to-moderate aerobic training program for HER2+ early-stage breast cancer patients undergoing targeted therapy seemed to have beneficial effect on the dynamics of troponin T-hs plasma levels, interpreted as a predictor for future cancer therapy-related cardiac dysfunction, but investigations on larger number of subjects are needed to further refine this issue.