No abstract

The purpose of this study was to assess the effect of chemotherapy on brain functional resting-state signal variability and cognitive function in older long-term survivors of breast cancer. This prospective longitudinal study enrolled women age ≥ 65 years of age who were breast cancer survivors after exposure to chemotherapy (CH), age-matched survivors not exposed to chemotherapy, and healthy controls. Participants completed resting-state functional brain MRI and neurocognitive testing upon enrollment (timepoint 1, TP1) and again two years later (timepoint 2, TP2). There were 20 participants in each of the three groups at TP1. The CH group showed a significant decrease in SDBOLD (blood-oxygen-level-dependent signal variability in standard deviation) in the right middle occipital gyrus (ΔSDBOLD = −0.0018, p = 0.0085, q (pFDR) = 0.043 at MNI (42, −76, 17)) and right middle temporal gyrus (ΔSDBOLD = −0.0021, p = 0.0006, q (pFDR) = 0.001 at MNI (63, −39, −12)). There were negative correlations between the crystallized composite scores and SDBOLD values at the right inferior occipital gyrus (correlation coefficient r = −0.84, p = 0.001, q (pFDR) = 0.016) and right middle temporal gyrus (r = −0.88, p = 0.000, q (pFDR) = 0.017) for the CH group at TP1. SDBOLD could be a potentially useful neuroimaging marker for older long-term survivors of breast cancer with exposure to chemotherapy.

Purpose The purpose of this prospective longitudinal study was to evaluate the changes in brain surface gyrification in older long-term breast cancer survivors 5 to 15 years after chemotherapy treatment. Methods Older breast cancer survivors aged ≥ 65 years treated with chemotherapy (C+) or without chemotherapy (C-) 5–15 years prior and age & sex-matched healthy controls (HC) were recruited (time point 1 (TP1)) and followed up for 2 years (time point 2 (TP2)). Study assessments for both time points included neuropsychological (NP) testing with the NIH Toolbox cognition battery and cortical gyrification analysis based on brain MRI. Results The study cohort with data for both TP1 and TP2 consisted of the following: 10 participants for the C + group, 12 participants for the C- group, and 13 participants for the HC group. The C + group had increased gyrification in 6 local gyrus regions including the right fusiform, paracentral, precuneus, superior, middle temporal gyri and left pars opercularis gyrus, and it had decreased gyrification in 2 local gyrus regions from TP1 to TP2 (p < 0.05, Bonferroni corrected). The C- and HC groups showed decreased gyrification only (p < 0.05, Bonferroni corrected). In C + group, changes in right paracentral gyrification and crystalized composite scores were negatively correlated (R = -0.76, p = 0.01). Conclusions Altered gyrification could be the neural correlate of cognitive changes in older chemotherapy-treated long-term breast cancer survivors.