Hi dear, Your question doesn t include many information that would help me understand your situation well so i could give you the best advice. Anastrozole decreases estrogen production, (estrogen helps cancer growth). This reduction eventually decreases that chances of the cancer to grow further or relapse.According to recent studies the results showed good outcome for patients. Another drug is Tamoxifen which is in a group of drugs knowne as selective estrogen receptor modulators (SERMs). Tamoxifen is another option for you since both have same results in different mechanisms, however according to some studies it s seen that Anastrozole has better effectivness.Other studies showed that Tamoxifen have long term side effect of causing uterine cancer. Overall, speak to your current Doctors if they can change you to Tamoxifen, they can give you best advice because they follow up with your case. Administring these drugs are case dependent. Wish you all the best. If you have more questions don t hesitate to ask.