Answer: "Chemobrain" is a very interesting and somewhat controversial topic. But one that is an area of very active research, so we'll know more about it in the next few years. What we can say is that women after a diagnosis of breast cancer -- and in particular, it seems to me, those who have received chemotherapy -- report difficulty with multi-tasking. And at the same time, some of the studies that have been done suggest that -- using formal tests -- that there is a difference in how they think and how they perform tasks, compared to what would be expected for women their age.
What is a little less clear is whether it has to do with the chemotherapy itself, or whether it's related to stress or a form of post-traumatic stress disorder; and I think they'll know more as the research matures. The good news is that it seems to be something that gets better with time. And so I think that, for women as they're about to go into chemotherapy, you'll be aware that you may not remember where your keys are all the time as well as before, for a short time, but that it should get better, and that none of it seems to be something that affects people permanently or in a particularly debilitating way.