Most recently, Dr. Castle was a tenured professor in the Department of Epidemiology and Population Health at Albert Einstein College of Medicine, Bronx, New York, and a visiting professor at institutions in Singapore, China and Australia. Dr. Castle was previously the Chief Scientific Officer of the American Society for Clinical Pathology. Dr. Castle has been a principal investigator for more than 15 years, initiating, conducting, and leading several large NCI molecular and clinical epidemiologic research studies in the U.S. and internationally, including the Mississippi Delta Project; the HPV (Human Papillomavirus) Persistence and Progression Cohort and the Guidelines Cohort at Kaiser Permanente Northern California (KPNC); and the Anal Cancer Screening Study.

Dr. Castle worked in the NCI Division of Cancer Epidemiology and Genetics (DCEG) as a fellow, investigator, and then senior investigator from 2002 through 2010. He has co-authored more than 400 published articles on HPV and cervical and anogenital cancers and other cancer-related research. Dr. Castle was named NCI Cancer Prevention Fellowship Distinguished Alumnus in 2017 and was honored with the Arthur S. Flemming Award for Government Service in Applied Science, Engineering, and Mathematics in 2010. Dr. Castle has received many professional honors and recognitions, which can be viewed in his full curriculum vitae (PDF, 819 KB), and his publications.