Targeted strength and endurance training during medication-based treatment prior to surgery for triple-negative breast cancer

Breast cancer (mammary carcinoma) is a malignant disease of the mammary gland tissue characterized by the uncontrolled proliferation of mammary gland cells. Treatment of the disease depends on numerous factors, such as the person’s general health, the stage of the disease, the tumor’s growth rate (Ki-67 index), detectable hormone receptors (HR) on the surface of the cancer cells (estrogen receptor-positive, progesterone receptor-positive), and the increased presence of HER2 receptors on the cells (HER2-positive).

Triple-negative breast cancer (estrogen receptor-, progesterone receptor-, and HER2-negative) often grows faster and is typically treated before surgery (neoadjuvant) with a combination of chemotherapy (including anthracyclines) and immunotherapy (e.g., pembrolizumab). Anthracyclines and immunotherapies can, among other adverse effects, damage the heart muscle and lead to heart weakness. At the same time, it is known that targeted endurance and strength training can strengthen the cardiovascular system, the musculoskeletal system, and quality of life.

The aim of this study is to investigate whether a structured endurance and strength training program improves physical performance and heart health during treatment. Patients will be randomly assigned to two groups: an intervention group and a control group. The control group will receive standard exercise recommendations for 24 weeks during neoadjuvant therapy. The intervention group will train at home for 24 weeks, guided by video and individually tailored (5 times per week, approximately 20 minutes each session, a combination of moderate endurance and interval training plus strength training). All patients receive a smartwatch for heart rate monitoring and trigger short ECG measurements at set times as well as when they experience symptoms. The study is double-blind, meaning that the researchers and those evaluating the results do not know which group the respective patients have been assigned to. The study primarily examines the change in maximal oxygen uptake (VO₂peak) from the start of the study through week 24. In addition, the study will assess, among other things, walking and standing tests (SPPB), echocardiography at rest and during exercise, blood tests (troponin, NT-proBNP), strength tests, and quality of life. Data collection takes place at the start of the study, after 6 and 12 weeks, at the end of the 24-week phase, and after 52 weeks. An exploratory analysis will examine whether exercise can reduce treatment-related heart damage (e.g., ICI-induced myocarditis, anthracycline-induced dysfunction).

Eligible participants are women between the ages of 18 and 65 with newly diagnosed, triple-negative breast cancer in the adjuvant setting, without distant metastases (stages 1–3), who are scheduled to receive anthracycline-based chemotherapy plus pembrolizumab prior to surgery. Participation is not possible in cases of unstable heart disease (e.g., acute heart failure, unstable coronary artery disease, significant arrhythmias) or orthopedic limitations that make exercise impossible.