This patient support community is for discussions relating to breast cancer, biopsy, genetics, chemotherapy, hormone therapy, lumps, lumpectomy, lymph node dissection, lymphedema, mammograms, mastectomy, radiation therapy, reconstruction, self exams, and stage 3 and 4 treatments.
I'm sorry that your sister has stage 4 breast cancer.
How old is your sister?
How is she doing now?
What is the level of her liver enzymes?
How long has she been on tamoxifen?
Arimidex can be an option if your sister is postmenopausal. If she is already on tamoxifen, this can be shifted to arimidex after 2 years.
There is a study comparing tamoxifen and raloxifene for breast cancer. You may want to check the link below.
Perhaps all these options should be discussed with your sister's oncologist.
Good luck.