My sister has 4th stage breast cancer, diagnosed when she was past menopause. All genetic tests came back negative. Her cancer is estrogen driven. I just began a course of Amberen, and had not had a period in over a year. The stuff works! ( I feel wonderful and my hot flashes are noticeably diminished.) One month into the treatment I spotted very lightly for one day. My gynecologist tested my blood and my estriadol level was 56, which is considered perimenopausal. Am I taking a chance by playing with my own hormones? Will this level of estriadol put me at risk for breast cancer?