Exercise during breast cancer chemotherapy showed no clear improvement in tumor response
A randomized trial reported favorable chemotherapy-delivery and fitness outcomes, while its main tumor-size comparison remained statistically inconclusive.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Adding supervised exercise during chemotherapy before breast cancer surgery did not produce a clear difference in tumor shrinkage or complete response. Exercise was associated with better chemotherapy delivery, shorter hospital stays and improved fitness. Those secondary findings suggest possible treatment-tolerance benefits, but they do not establish that exercise improves tumor response.
The tumor-size confidence interval allowed differences in either direction. This abstract-based account cannot assess the magnitude of the favorable chemotherapy-delivery and hospitalization findings because their effect sizes and uncertainty estimates are not provided.
What researchers found
Between-group difference in median tumor-size change
Exercise versus usual care, assessed by MRI from study entry to the assessment before surgery. The confidence interval shows uncertainty spanning differences in either direction.
Tumor response was the main test
The main outcome was the change in tumor size on MRI. Complete response was also assessed through imaging and pathology; neither comparison showed a statistically detectable difference between exercise and usual care.
Other outcomes were mixed
Exercise participants had fewer chemotherapy delays and improved fitness, strength and activity levels. The trial detected no differences in quality of life, body composition, rehabilitation participation or the reported measures of psychological wellbeing.
The original publication
Effects of Supervised Exercise during Neoadjuvant Chemotherapy on Tumor Response in Patients with Breast Cancer (Neo-train): A Randomized Controlled Trial.
Kjeldsted E, Ammitzbøll G, Lænkholm AV et al.
Clin Cancer Res · 2025
- PubMed ID
- 40788186
- Record checked
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