My aunt had breast cancer...after she had a rare form of blood cancer. Complications of both finally took her in May of last year. It was such a shock to the family because both cancers were in remission...their effects apparently weren't.
My mom's best friend had breast cancer and had a breast removed. (My aunt did as well). She went into remission for 10 years and then the cancer came back with a vegence and spread through her entire body. Doctors gave her a matter of weeks to live. She lived more than 3 years and was able to spend time with her four granddaughters, who she might never have seen had the doctors been right.