Taxoxifen and age of patient

Is tamoxifen as useful to a woman of 75 as for a pre-menapausal woman? In other words, does age make a difference as to who should be on tamoxifen.  (I just had a lumpectory and radiation for a stage one tumor.) Thanks in advance.

[CCF-RN,MSN-JS]

Dear ning, Some breast tumors are found to be estrogen receptor positive, meaning that the presence of estrogen may have a role in stimulating their growth. Tamoxifen blocks the estrogen receptor in the breast and on the cancer cell so that the estrogen can not get to them to stimulate the growth of cancer.  After menopause the ovaries stop producing large amounts of estrogen (enough to stimulate ovulation), however a small amount is still produced and available in the body.  This is why tamoxifen is used even in women after menopause.