19 April 2016


The parent SOFT (see trials in follow-up) was done to see if suppressing ovarian function, plus giving tamoxifen or exemestane is better at preventing the return of breast cancer than giving tamoxifen alone in premenopausal/younger women. The cognitive function sub-study evaluated the effects of these hormone treatments on memory and thinking (cognitive function).


It is known that oestrogen has an important role in brain function and so it is possible that these hormone treatments might affect cognitive function, however very few studies have been completed to investigate this. It is important to clarify any effect of hormonal treatments on cognitive function in younger women so that in the future women with breast cancer will have better information on which to base their treatment choices.

Scientific Title

The Cognitive Function Sub-study to the Suppression of Ovarian Function Trial (SOFT)


The Co-SOFT study provides no evidence that adding ovarian function suppression to oral endocrine (hormonal) therapy substantially affects overall cognitive function.


Adjuvant ovarian function suppression and cognitive function in women with breast cancer. Phillips KA, Regan M, Francis P, et al for Co-SOFT Investigators. British Journal of Cancer. 26 April 2016. 114 (9); 956 -964.