Dr. Ian Thompson, SWOG (IMAGE) SWOG Caption Dr. Ian Thompson, Jr., was principal investigator of SWOG's Prostate Cancer Prevention Trial, one of the largest cancer prevention trials ever conducted. Credit SWOG/The Hope Foundation Usage Restrictions Please credit SWOG/The Hope Foundation License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.