Alterations in Brain Activation During Working Memory Processing Associated With Breast Cancer and Treatment: A Prospective Functional Magnetic Resonance Imaging Study

Abstract

A B S T R A C T PurposeTo prospectively examine alterations in working memory (WM) -associated brain activation related to breast cancer and treatment by using functional magnetic resonance imaging. Patients and MethodsPatients treated with chemotherapy (CTxϩ; n ϭ 16) or without chemotherapy (CTxϪ; n ϭ 12) and healthy controls (n ϭ 15) were scanned during an n-back task at baseline (after surgery but before radiation, chemotherapy, and/or antiestrogen treatment), 1 month after completion of chemotherapy (M1), and 1 year later (Y1), or at yoked intervals for CTxϪ and controls. SPM5 was used for all image analyses, which included cross-sectional between-group and group-by-time interaction and longitudinal within-group analyses, all using a statistical threshold of 0.001. ResultsAt baseline, patients with cancer showed increased bifrontal and decreased left parietal activation compared with controls. At M1, both cancer groups showed decreased frontal hyperactivation compared with controls, with increased hyperactivation at Y1. These cross-sectional findings were confirmed by group-by-time interaction analyses, which showed frontal activation decreases from baseline to M1 in patients compared with controls. Within-group analyses showed different patterns of longitudinal activation change by treatment group (CTxϩ or CTxϪ), with prominent alterations in the frontal lobes bilaterally. ConclusionSignificant frontal lobe hyperactivation to support WM was found in patients with breast cancer. Superimposed on this background, patients showed decreased frontal activation at M1, with partial return to the previously abnormal baseline at Y1. These functional changes correspond to frontal lobe regions where we previously reported structural changes in this cohort and provide prospective, longitudinal data that further elucidate mechanisms underlying cognitive effects related to breast cancer and its treatment.

Default mode network connectivity distinguishes chemotherapy-treated breast cancer survivors from controls

“…These previous results in combination with our present findings suggest that there are likely region-and/or network-specific effects of cancer and its treatments. For example, C− may be more associated with prefrontal network disruption compared with DMN (11,32,35). However, it is also possible that our sample sizes were too small and/or the cross-sectional nature of the present study prevented us from detecting differences in DMN in the C− group.…”

Challenges in research on the neural basis of „chemobrain”

“…In line with the findings from the animal work reported above, diffusion tensor imaging (DTI) studies have found chemotherapy-related reductions of white matter integrity that correlated with cognitive performance [30]. A prospective DTI study Paradigms included verbal long-term memory [37,38], verbal working memory [39,40], and tasks requiring rule testing or planning, both involving prefrontal cortex [41,42]. Activation …”

Associations Between Physical Fitness Indices and Working Memory in Breast Cancer Survivors and Age-Matched Controls

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