I think going by the information out there, breast cancer is treated less agressively in those over 65. There are also losts of co morbilities the older you get.
Older people tend to take longer to recover than younger ones, and the cancer tends to grow more slowly the older you get. Although breast cancer tends to be more agressive the younger you are. As most other cancers are.
But compared with other types of cancer breast cancer is high on the survival rate , but something like pancreatic is one of the worst to get.
PMx