My mother in law who is 92 and has early onset dementia with type 2 diabetes and stage three kidney disease has been prescribed with letrozole. Did to the dementia we were unaware she had cancer but when an ecg was carried out a small tumour and disfiguration of her breast was discovered. She is a frail 92 year old, already tired most of the time, spends great deal of day immobile although we try to walk 20 mins a day. We are worried about starting the prescription because of possible side effects and how this will impact on her when she is already not in the best of health. The breast clinic were unable to give an indication of how long she's had the cancer for. They said take the drug and we will see her in three months time! Any advice? Should we just let nature take its course of inflict more suffering on her with possible side effects?