Chemo brain: an unintended consequence of treatment for breast cancer. Women so afflicted and their Oncologists have known for over ten years that chemotherapy given after a breast cancer diagnosis to try to prevent metastasis causes changes in memory and concentration in a large percentage of women. Only recently has this phenomenon been studied rigorously. Changes in brain structure have been demonstrated on MRI scans with treatment and changes in brain function can be seen on PET scan. A recent report by McDonald et al in the July 10, 2012 Journal of Clinical Oncology has shed further light on this phenomenon. These investigators, from Indiana University, Dartmouth and Memorial Sloan Kettering in New York did special MRI scans on women newly diagnosed with breast cancer, months later at the end of their chemo, and one year later. They found profound changes in brain activity in specific areas of the brain at diagnosis pre-treatment, and increasingly abnormal activity in these areas after chemo was done. After a year the scans came back to pre-treatment levels but were not normal. This paper for the first time using this technique shows how cancer affects the brain irrespective of treatment, even when it hasn’t spread to the brain, and how treatment can make this situation worse. The implications are huge, in that at least ten women receive adjuvant chemotherapy for every one who is actually saved from dying. The other nine women arguably have wasted their time and effort. If in the process they suffer brain damage the cost/benefit ratio flips remarkably. For those of you who wish to read an abstract of this paper it can be found here. The full article can only be read if you subscribe to the journal. This field is evolving rapidly. Stay tuned for new developments.