Professor Stewart Justman discusses his new book "Do No Harm" in which the results of the Prostate Cancer Prevention Trial cause us to reflect on Hippocratic ethical principals of 300BCE in our present practice. Finasteride leaves us with an ambiguity of reducing the incidence of cancer but also associated with a higher rate of aggressive neoplasm. In chemoprevention is any risk too much to be expectable? Hosted by Maurie Pickard.