I don't know about breast cancer, but i do know with cervical cancer the treatment regimes are aggressive and not necessarily evidence based (unless you count the "if thy hand offend thee" approach to treatment). I have a friend who had stage 1 and 2 cell changes (which can come and go and do NOT necessarily mean the cells will become cancerous) she was told her options "we could wait and see, but you could get aggressive cancer, or we can operate to remove the problem before it becomes a REAL problem" - she opted for a cone biopsy, and is now on her 3rd pregnancy with a cervical stitch, the first 2 having ended in 2nd tri losses due to incompetant cervix. THey have actually convinced her it is "95% sure" her cervix was incompetant before they cut half of it away. *shaking my head*
Don't get me wrong, my mother DIED of cervical cancer, i know it can be a killer, but she NEVER missed a smear and because the cancer began within the cervical canal, not near the os, she was back and forth to the well woman clinic every 3 weeks with unexplained post-menopausal bleeding for 18 months before they decided to do a scan. By then she had grade 4 tumour and secondaries, it was terminal. I always wonder if the often unwarranted hyper-aggressive treament when they DO catch these things early is a way of protecting the fragile denial of the truth - that cancer isn't always curable and despite the best allopathic medicine has to offer nowadays people still die.