A recent study confirmed the long-term superior efficacy and safety of anastrozole (Arimidex) over tamoxifen as initial adjuvant
therapy for postmenopausal women with
hormone-sensitive early
breast cancer.
It is apparently considered likely that this would hold true for the other AIs, such as Aromasin, but if you wish, you could ask your doctor about the possibility of trying Arimidex in place of Aromasin.
Best wishes...