MS-N315 · Exercise and rehabilitation · Cardiovascular risk · Childhood-cancer survivorship · Human evidence · Appraised 12 November 2026

Does a year-long physical-activity program reduce cardiovascular risk in long-term survivors of childhood cancer?

Evidence at a glance

• Evidence label: Randomized controlled trial; small improvement in a composite cardiovascular-risk score, with adherence and injury concerns
• Benefit: The composite risk z-score improved by 0.18 more than control at 12 months; individual clinical-event prevention was not tested.
• Certainty: Moderate for the composite surrogate outcome; low for preventing heart attacks, stroke or death.
• Risk: In related SURfit safety reporting, 11 adverse events were considered likely intervention-related, including strains, ankle-ligament injuries, back pain and psychosocial events.

What was studied

Design and population: SURfit randomized 151 Swiss survivors aged at least 16 years, diagnosed before age 16 and at least five years in remission (76 intervention, 75 control). Mean age was 30.4 years and 44% were women.

Regimen: Participants were asked to add at least 2.5 hours of intense activity weekly for one year, including about 30 minutes of strengthening and two hours of aerobic exercise, supported by physiotherapy consultations, web diaries and pedometers. Controls continued usual activity.

Primary outcome: A composite z-score averaging waist circumference, blood pressure, fasting glucose, inverted HDL, triglycerides and inverted cardiorespiratory fitness—not cardiovascular events.

What the evidence found

At 12 months, the intention-to-treat between-group difference in change in the composite cardiovascular-risk z-score was −0.18 (95% CI −0.29 to −0.06; P=.003), favoring intervention. Similar direction was reported at six months.

Nineteen participants dropped out—13 intervention and six control. A prespecified adherence report found only 48% of intervention participants met at least two-thirds of their individualized activity goal; 17% of controls increased activity enough to count as contamination.

Across related SURfit outcome reporting, 170 adverse events were recorded (91 intervention, 78 control; one event lacked clear arm assignment in the accessible text). Eleven were considered likely related to the intervention: strains/overstretching, ankle-ligament injuries, back pain, other injuries and psychosocial events. Serious events occurred but were not established as caused by exercise.

How to interpret it

The composite score suggests modest risk-factor improvement, not proof that the program prevents cardiovascular disease. A change in a z-score is difficult to translate into an individual absolute event reduction.

Low adherence and control-group activity blur the contrast but also reflect real-world difficulty sustaining a year-long intensive goal. Survivors with cardiotoxic treatment exposure may need individualized surveillance in addition to exercise.

Practical safety context

Late effects can include cardiomyopathy, arrhythmia, pulmonary limitation, endocrine disease, neuropathy and low bone density. Prior anthracycline or chest-radiation exposure may warrant risk-based cardiac assessment before intense exercise.

Rapid escalation raises strain and ligament-injury risk. Progression, footwear, balance, pain, mental-health status and access to physiotherapy matter.

Questions for the care team

• Do my childhood-treatment exposures require echocardiography or other clearance before vigorous activity?
• Would a gradual moderate-intensity plan be safer than the trial’s intense target?
• Which cardiovascular risk factors will we measure separately, not only as a composite?

Funding and conflicts

Supported by the Swiss Cancer League and several Swiss childhood-cancer and cancer-research foundations; reported funders had no role in design, analysis or publication.

Sources

• SURfit cardiovascular trial (PMID 37653075)
• Full SURfit cardiovascular report (PMCID PMC10575964)
• SURfit adherence report (PMID 37199378)
• ClinicalTrials.gov NCT02730767

Last literature search: 12 November 2026. Record appraisal: 12 November 2026. The full cardiovascular report, adherence report and related safety reporting were appraised. This page is educational and does not replace individualized medical advice. These supportive-care outcomes do not establish tumor shrinkage, delayed recurrence or longer survival.