Allan Hildesheim, Ph.D.
|Organization:||National Cancer InstituteDivision of Cancer Epidemiology & Genetics, Infections and Immunoepidemiology Branch|
|Address:||Executive Plaza SouthRoom 7066|
Dr. Hildesheim received a Ph.D. in epidemiology from The Johns Hopkins School of Hygiene and Public Health in 1991. He has been at the NCI since 1987 and is currently the Chief of the Infections and Immunoepidemiology Branch. Dr. Hildesheim's research focuses on understanding host and viral factors involved in the pathogenesis of DNA virus-related tumors and in the evaluation of efficacy and underlying immunological mechanisms associated with the recently licensed prophylactic HPV vaccines.
We are conducting large-scale population studies to investigate exogenous and host factors involved in the pathogenesis of DNA virus-related tumors. Two groups of tumors are under investigation: female gynecological cancers linked to HPV and nasopharyngeal cancer linked to EBV. Non-viral factors involved in the pathogenesis of HPV and EBV-related cancers are also being examined, since infection alone is rarely sufficient for the development of cancer. We are also involved in the evaluation of the long-term impact of HPV vaccination and in elucidating immunological mechanisms involved in long-term vaccine efficacy. To this end, Dr. Hildesheim is the lead NCI investigator on a 7,465 women community-based HPV-16/18 Vaccine Trial in Costa Rica.
Our previous studies suggested that in addition to HPV infection, important determinants of cervical disease progression may include host immune response to HPV; exogenous and behavioral factors, such as parity, smoking and oral contraceptive use; and infection with sexually transmitted agents other than HPV. To further define the factors related to persistence of HPV infections and to the progression of these infections to high-grade cancer precursors, I have been involved in several U.S and international case-control and cohort studies, the largest of which is a population-based study of 10,000 women in Costa Rica who were enrolled and followed for 7 or more years. Within this large cohort, we have nested studies that have allowed us to evaluate immunological factors associated with HPV persistence, inherited genetic factors linked to persistence and progression of HPV infections, and other exogenous factors. We have also had the opportunity to explore mucosal immunological factors and their determinants.
HPV vaccines designed to prevent infection and associated lesions associated with oncogenic HPV types 16 and 18 have been licensed in many countries. These vaccines have the potential to profoundly impact cervical cancer prevention strategies, and if applied wisely to reach underserved populations that have historically not benefited from secondary prevention programs based on Pap smears. Dr. Hildesheim is the lead NCI investigator on a 7,465 women community-based HPV-16/18 vaccine trial in Costa Rica. Initiated in 2004, this trial is designed to evaluate the safety and efficacy of the HPV-16/18 vaccine, to examine broader questions of long-term population impact of vaccination, and to explore cost-effective ways in which HPV-based vaccination and screening might be applied in the future. The trial involves active follow-up of participants and includes a rich biological specimen collection component that allows for the added evaluation of numerous scientific questions of etiological and immunological interest.
Nasopharyngeal cancer has a very distinct geographic and ethnic distribution, occurring at high rates among ethnic Chinese from southeastern China and at much lower rates among Caucasians. While infection with EBV is believed to be necessary for development of the cancer, both genetic and exogenous factors are also thought to be important. Dr. Hildesheim has conducted several studies of NPC in Taiwan, including a case-control study of largely sporadic tumors (>1,000 participants) and a family-based study of multiplex NPC families (>3,000 participants from >350 families). These studies serve as the foundation from which numerous hypotheses related to genetic and environmental risk factors for NPC are being investigated.