Peter Greenwald

Peter Greenwald built the cancer prevention research infrastructure at the National Cancer Institute, establishing the Division of Cancer Prevention and launching systematic clinical trial programs that evaluated tamoxifen, finasteride, selenium, and dietary interventions for cancer risk reduction. His creation of the Chemoprevention Branch enabled the first generation of large-scale randomized cancer prevention trials. He initiated the 5-A-Day public health campaign promoting fruit and vegetable consumption for cancer prevention.