The breast cancer drug tamoxifen does not damage the brains of elderly women, alleviating fears of a neurotoxic effect of such treatment, recent study has revealed. According to researchers, tamoxifen has a similar effect on the brain to oestrogen, which has been linked with potentially neuroprotective action against cognitive decline.
The researchers used proton magnetic resonance spectroscopy to determine levels of the cerebral metabolite myo-inositol, which has been found at elevated levels during brain injury, in the brains of 80 women. Sixteen of the women were breast cancer patients who had received tamoxifen therapy for at least two years beforehand, 27 were healthy women who had received preventative oestrogen-based hormone replacement therapy (HRT) for at least two years and 33 were healthy women who had received neither tamoxifen nor HRT.
Dr Ernst and colleagues found that women who had received tamoxifen or oestrogen had lower levels of myo-inositol than the controls who had received neither treatment. The women who had received tamoxifen for the longest period of time had the lowest levels of the metabolite present in their brains.
The researchers concluded that both tamoxifen and oestrogen may have neuroprotective effects, and may modulate the effect on the brain. They added that further research is needed to determine the effects of oestrogen and tamoxifen on cognition.