Ian M. Thompson Jr., M.D., is the director of the Cancer Therapy & Research Center and a urologic oncologist who specializes in prevention, early detection, and treatment of prostate and other urologic cancers, including cancers of the kidney, bladder and testis. He serves as a trustee of the American Board of Urology, chairman of the Early Detection Research Network of the National Cancer Institute, and chair of the Genitourinary Cancer Committee of the Southwest Oncology Group, one of the largest cancer treatment trials organizations in the world. He was principal investigator of the Prostate Cancer Prevention Trial, an 18,882-subject study published in 2003 that demonstrated that finasteride can reduce the risk of prostate cancer. In 2004, he and his colleagues published a major discovery, finding that cancers, including aggressive prostate cancers, can be present at lower levels of prostate-specific antigen. He continues to oversee multiple major studies in the United States and abroad with the goal of preventing, detecting or curing prostate cancer.