Cancer-related cognitive impairment (CRCI) is a common side effect of breast cancer treatment and has been linked to structural brain abnormalities. As previous research showed that mindfulness-based interventions (MBI) might alter brain structure, we hypothesized that MBI can induce structural brain recovery after chemotherapy in breast cancer survivors with cognitive complaints.
Female breast cancer survivors reporting cognitive complaints (n = 117) were randomly assigned to a mindfulness (n = 43), physical training (n = 36), or waitlist control condition (n = 38). Multimodal MRI was used to investigate differences between groups in gray matter volume changes using a voxel-based morphometry analysis, and white matter structure using a fixel-based whole-brain and tract-based analysis.
Ninety-five participants completed structural MRI scans before the intervention, immediately after, and 3 months post-intervention. Comparing MBI to the waitlist control group, results showed an increase in gray matter volume in the right primary motor cortex immediately after MBI compared to baseline. Tract-based analysis showed small regional differences within the corpus callosum between both intervention groups and the waitlist controls. No differences in the whole-brain white matter or between MBI and physical training could be identified.
This study showed that MBI may be associated with subtle short-term structural brain changes in a region involved in the control of voluntary movements and pain processing, which might indirectly impact cognitive functioning. However, no long-term effects were found, suggesting that longer interventions might be needed to widely affect brain structure and associated CRCI. Nonetheless, MBI might show promise as a non-invasive intervention in the context of CRCI.
The study was registered at clinicaltrial.gov (NCT03736460).