Cognitive impairment following hormone therapy: current opinion of research in breast and prostate cancer patients
Wu LM; Amidi A
Current Opinion in Supportive & Palliative Care2017
Summary (paraphrased)
This review compares cognitive effects of hormone therapy in breast cancer (estrogen blockade) and prostate cancer (androgen blockade) populations. It emphasizes that estrogen and androgen receptors are densely distributed in memory-relevant brain regions such as the hippocampus and cortex, and that testosterone reaches the brain both directly and via local conversion — 5α-reduction to DHT or aromatization to estradiol, which is itself neuroprotective and regulates synaptic plasticity and neurogenesis. The authors argue that disrupting sex-steroid signaling in either sex can impair cognition, and they flag shortcomings in the existing literature while proposing research directions.
Why it’s in the systems review
This is the axis's receptor-level record: androgen and estrogen receptors in the hippocampus and cortex make the brain a direct target of androgen-axis disruption, not just a downstream casualty of low circulating testosterone. Its explicit discussion of testosterone's dual brain fate — conversion to DHT by 5α-reductase or to estradiol by aromatase — ties the hormonal-axes axis back to 5AR (the finasteride target) and to the Melcangi-group theme of altered neuroactive-steroid signaling in the brain. It also provides the rationale for why manipulating steroid synthesis enzymes, not just replacing testosterone, is the mechanistically interesting treatment-candidate space.