Both drugs are relatively inexpensive with modest side effects, but only about 5 to 20 percent of high risk women use them to reduce their risk of breast cancer, said Gabriel Hortobagyi, MD, chair of breast medical oncology at M buy priligy online usa Whether extending treatment beyond five years is more beneficial or harmful than the five year course is a question doctors will not be able to fully answer until 2010, the head of the team, Prof