ALTERATIONS involving several brain networks could help explain cancer-related cognitive impairment amongst breast cancer survivors, according to a review of neuroimaging studies.
The research identified associations involving networks linked to attention and cognitive function. The findings suggest that changes across multiple interconnected systems may contribute to the varied difficulties experienced by survivors, rather than impairment being confined to a single brain region.
Cancer-related cognitive impairment can involve difficulties with memory, attention, concentration, and processing speed, with symptoms sometimes persisting for years after treatment. However, the underlying mechanisms and their relationship with measurable brain changes remain incompletely understood.
Researchers reviewed six diffusion tensor imaging studies, six voxel-based morphometry studies, and ten functional MRI studies. The respective imaging groups included 282, 177, and 328 participants.
These techniques provide different perspectives on brain structure and function, allowing researchers to examine reported alterations across complementary imaging approaches.
Using the Yeo seven-network atlas, the team assessed how brain regions implicated in cognitive impairment overlapped with established functional networks. Statistical analyses then examined associations between the reported changes and particular networks.
The analysis identified significant associations involving the dorsal attention, default mode, frontoparietal, and ventral attention networks.
The researchers highlighted the default mode and frontoparietal networks as particularly relevant candidates for further investigation into disease tracking and potential therapeutic applications. However, the pattern of associations varied between imaging techniques, indicating that different methods captured different aspects of the reported alterations.
These findings support the possibility that cognitive impairment involves several networks. Such involvement could help explain why survivors report difficulties across multiple cognitive domains and with demanding everyday activities.
The results do not establish that a particular network alteration directly causes an individual patient’s symptoms. They instead provide a framework for investigating the neural processes that may contribute to cognitive difficulties following breast cancer treatment.
The review was limited by the relatively small number of studies and substantial variation in treatment regimens, patient characteristics, imaging methods, and assessment timing. Scans performed weeks after treatment may capture different processes from those obtained years later.
Most included studies did not systematically account for factors such as depression, anxiety, fatigue, or menopausal status. The review also primarily considered studies reporting positive neuroimaging findings, which could limit the completeness of the overall picture.
The researchers cautioned that evidence linking early MRI changes with long-term cognitive outcomes remains limited. MRI is therefore not established as a routine screening approach for cancer-related cognitive impairment.
Nevertheless, the findings could guide further research into biomarkers and targeted interventions. More consistent assessment methods and studies incorporating both positive and negative findings could help clarify their relevance to survivorship care.
Reference
Benelli A et al. Functional brain network alterations linked to cancer-related cognitive impairment in breast cancer patients. Oncologist. 2026;31(10).
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