Structural brain changes and cognitive deficits were identified in a subset of breast cancer patients within 12 months of receiving anthracycline-taxane chemotherapy, according to a study presented at the Alzheimer’s Association International Conference 2025 in Toronto.
Chemotherapy-induced neuroinflammation may contribute to neurovascular unit disruption and vascular toxicity, leading to structural changes in the brain that underlie cognitive impairment. This condition, often called “chemobrain,” is estimated to affect about 33% of breast cancer survivors. While some patients experience a transient cognitive decline that resolves within 1 year, others face persistent symptoms.
The study enrolled 270 breast cancer patients who had completed chemotherapy in the past year. All participants underwent neurocognitive pre-screening via an artificial intelligence–based online platform. From this group, 18 patients with lower scores and 19 matched controls were selected for further in-person cognitive testing and brain imaging.
Researchers used 3-Tesla magnetic resonance imaging to assess structural brain changes. Images were analyzed through Region of Interest (ROI) and Voxel-Based Morphometry (VBM) methods. Patients also underwent in-person neurocognitive assessments.
ROI analysis revealed significantly lower grey matter volume in the left isthmus cingulate and left pars opercularis regions of chemotherapy patients compared with controls. Decreased grey matter surface area was also observed in the left medial orbitofrontal cortex, right isthmus cingulate, lingual gyrus, and temporal pole.
VBM analysis showed additional reductions in grey matter density in the periventricular areas, cingulate gyrus, precuneus, parietal lobes, and medial frontal lobes in the chemotherapy group. These regions are associated with memory, attention, and executive function.
Cognitive testing results showed significantly lower Mini-Mental State Examination (MMSE) scores among chemotherapy patients. Patients also performed worse in semantic and verbal fluency tasks than controls. The study reported statistically significant differences, though specific MMSE scores were not detailed.
Many of the affected brain regions are involved in cognitive networks commonly disrupted in neurodegenerative disorders such as small vessel disease, vascular dementia, and Alzheimer’s disease. Several regions belong to the default mode network, which is known to be altered in Alzheimer’s disease.
The authors indicated that better understanding these brain alterations may aid in early detection and clinical monitoring of chemotherapy-associated cognitive impairment in cancer survivors.
Source: AAIC 2025