"Exercise Intervention to Increase Physical Activity in Young Sarcoma Survivors (Sport Ist Herzenssache)"

Overview

Survivors of bone and soft tissue sarcoma often face long-term health problems after their cancer treatment, such as muscle weakness, joint stiffness, and reduced heart and lung fitness. Because of this, many survivors are less physically active than their healthy peers, which can further increase their risk of heart disease and other late effects later in life. This study, called "Sport ist Herzenssache" ("Sports is a Matter of the Heart"), tests whether a personalized exercise program can help young survivors (aged 15-39) become more physically active. All participants receive a fitness tracker (smartwatch) to monitor their daily activity. Half of the participants are randomly assigned to also receive an individualized home exercise plan, including strength and endurance training, with some sessions guided online by an exercise specialist. Before and after an 8-week exercise period (with continuous activity tracking for about 13 weeks total), participants complete simple physical tests (such as walking and balance tests), a heart and fitness check-up, and questionnaires about their quality of life and energy levels. The main goal is to find out whether the personalized exercise plan helps participants become more active in daily life, measured in minutes of moderate-to-intense activity per day. The study also looks at effects on heart health, physical function, and overall well-being. The results will help determine whether structured exercise support should become a standard part of long-term follow-up care for young sarcoma survivors.

Survivors of pediatric and adolescent bone and soft tissue sarcomas frequently experience long-term sequelae including reduced muscle strength, impaired joint mobility, and diminished cardiorespiratory fitness, often resulting from multimodal oncological therapy (surgery, chemotherapy, radiotherapy). These sequelae contribute to persistently low levels of physical activity compared to healthy peers, which in turn is associated with an elevated risk of cardiovascular disease-a risk already increased 2- to 10-fold in this population due to cardiotoxic treatment exposure (e.g., anthracyclines, thoracic irradiation). Despite established benefits of physical activity in reducing fatigue, improving quality of life, and lowering cardiovascular morbidity, structured exercise programs are not yet routinely integrated into long-term follow-up care for sarcoma survivors. This monocentric, randomized controlled trial ("Sport ist Herzenssache") aims to evaluate the effectiveness of an individualized, partially supervised, digitally supported exercise intervention in increasing moderate-to-vigorous physical activity (MVPA) among adolescent and young adult (AYA) survivors of bone and soft tissue sarcoma during routine oncological follow-up care. Eligible participants are aged 15-39 years, have completed local tumor therapy (surgery and/or radiotherapy) more than 12 months prior to enrollment, and are receiving follow-up care at the Sarcoma Center of the University Hospital Essen. Following informed consent, participants will be randomized 1:1, stratified by tumor location (lower extremity/pelvis, thorax, other), into two groups: (1) a control group receiving a wearable activity tracker (Garmin Venu® Sq 2) for self-monitoring, and (2) an intervention group receiving the same wearable device plus an individualized, partially supervised home-based exercise program over 8 weeks, combining endurance/cardio training (60 min/week) and strength/aerobic sessions (3 × 30 min/week), in accordance with WHO physical activity recommendations and exercise guidelines for cancer survivors. Supervised sessions are delivered via video conferencing by trained exercise therapists. Physical activity is monitored continuously via wearable device across a total observation period of approximately 13-15 weeks in both groups. At baseline and after the observation period, participants undergo a comprehensive assessment including functional mobility testing (Timed Up and Down Stairs, Timed Up and Go, 6-Minute Walk Test, modified Clinical Test of Sensory Interaction in Balance), goniometry, handheld dynamometry, and cardiopulmonary evaluation (spiroergometry, echocardiography, 12-lead ECG). Patient-reported outcomes include health-related quality of life, cancer-related fatigue, physical functioning, and self-rated health status. The primary endpoint is average daily MVPA (minutes/day), measured objectively via wearable device. Secondary endpoints include cardiorespiratory fitness (VO2max), cardiovascular risk factors, orthopedic function, and patient-reported quality of life and fatigue. Exploratory analyses will examine correlations between MVPA and physical/psychosocial outcomes, as well as associations with physical activity levels during acute cancer therapy. Based on a two-sided t-test with α = 0.05 and 80% power, a total sample size of n = 42 (21 per arm) is required to detect a clinically meaningful increase in MVPA from an expected baseline of 40 min/day (SD = 20) toward the WHO-recommended target of 60 min/day. Accounting for an estimated 10% dropout rate, recruitment aims to enroll 46 participants over a two-year period. This study addresses a critical gap in survivorship care by generating evidence on the feasibility and efficacy of a structured, individualized exercise intervention to promote long-term physical activity, cardiovascular health, and quality of life in young sarcoma survivors, with the goal of informing the integration of exercise therapy as a standard component of long-term oncological follow-up care.