I understand that atypical ductal hyperplasia can be a precursor to BC so your doctor has ordered one of the anti-estrogen drugs although I'm not familiar with the drug you mentioned. I am on Femara after having stage 1 BC. Of course, anti-estrogen drugs will only work if you are prone to having estrogen or progesterone positive fueled dysplesia or carcinoma. Some of these drugs are not without side effects. I personally have not suffered any ill side effects from Femara but many woman have written that they have. Like anything else the benefits have to be wade against the risk, certainly if this drug can prevent the occurrence or delay occurrence it may be worth trying.