Estrogen- and tamoxifen-associated effects on brain structure and function.
We evaluated the effects of estrogen and tamoxifen, a selective estrogen receptor modulator, on positron emission tomography (PET) measures of brain glucose metabolism and magnetic resonance imaging (MRI) measures of hippocampal atrophy. Three groups of postmenopausal women were studied, women taking estrogen (ERT+), women with breast cancer taking tamoxifen (TAM), and women not taking estrogen or tamoxifen (ERT-). All subjects received a PET scan, an MRI scan, and cognitive testing. The TAM group showed widespread areas of hypometabolism in the inferior and dorsal lateral frontal lobes relative to the other two groups. The ERT- group showed lower metabolism in the inferior frontal cortex and temporal cortex with respect to the ERT+ group. The TAM group also showed significantly lower semantic memory scores than the other two groups. Finally, the TAM group had smaller right hippocampal volumes than the ERT+ group, an effect that was of borderline significance. Both right and left hippocampal volumes were significantly smaller than the ERT+ group when a single outlier was removed. The ERT- group had hippocampal volumes that were intermediate to the other two groups. These findings provide physiological and anatomical evidence for neuroprotective effects of estrogen.
Eberling
Jamie L
JL
Department of Neurology and Center for Neuroscience, University of California, Davis, CA 95616, USA. jleberling@lbl.gov
Wu
Christine
C
Tong-Turnbeaugh
Regina
R
Jagust
William J
WJ
D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects / Q000627:therapeutic use*; D001284:Atrophy; D001288:Attention / Q000187:drug effects; D001786:Blood Glucose / Q000378:metabolism; D001943:Breast Neoplasms / Q000188:drug therapy*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000473:pathology; D004193:Discrimination Learning / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D015914:Estrogen Replacement Therapy; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects / Q000473:pathology; D006624:Hippocampus / Q000187:drug effects* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008570:Memory, Short-Term / Q000187:drug effects; D008875:Middle Aged; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000187:drug effects; D013629:Tamoxifen / Q000009:adverse effects / Q000627:therapeutic use*; D013702:Temporal Lobe / Q000187:drug effects / Q000473:pathology; D014055:Tomography, Emission-Computed; D014706:Verbal Learning / Q000187:drug effects
D018931:Antineoplastic Agents, Hormonal; D001786:Blood Glucose; D013629:Tamoxifen