About the Branch

Overview

The Infections and Immunoepidemiology Branch (IIB) formerly known as the Viral Epidemiology Branch (VEB) conducts multidisciplinary studies of carefully selected domestic and foreign populations, with the goal of clarifying the relationship of infectious agents, especially viruses, to human cancer and other conditions. Viruses may cause or increase the risk of malignancy through several mechanisms, including direct transformation, expression of "oncoproteins" that interfere with mitosis check points or DNA repair, expression of cytokines or other growth factors, and alteration of the immune system. While some viruses have been related to cancer for many years, new agents continue to be found. Recent branch research has concentrated on human retroviruses (HIV-1 and human T-lymphotropic viruses types I and II (HTLV-I and -II)), with additional studies on human papillomaviruses (HPV), hepatitis viruses, papovaviruses, and human herpesviruses (HHV), especially HHV-8, which was discovered in 1994 and has been linked to Kaposi's sarcoma, a rare type of non-Hodgkin's lymphoma, and perhaps other malignancies.

Because these viruses are exogenous, their biology, transmission routes, and natural history can be identified. The Branch utilizes the principles of both infectious and chronic disease epidemiology, supported by statistical modeling and laboratory investigations conducted either at collaborating sites or at our Human Retrovirus Laboratory at the Frederick Cancer Research and Development Center.

Some cancer-associated viruses appear to rarely cause cancer. Other viruses, however, substantially increase the risk for cancer and the burden of this disease in the population. HIV-1 is responsible for substantial increases (18%) in cancer in young adults in the United States. Although it is not yet clear how to prevent most cancers that occur among HIV-infected persons, understanding the transmission routes and preventive measures should lower the incidence of infection, and the subsequent risk of non-Hodgkin's lymphoma and Kaposi's sarcoma. Similarly, reducing HTLV-I transmission will lower the incidence of adult T-cell leukemia/lymphoma. Furthermore, knowing which cancers are associated with the different viruses helps to promote targeted cancer screening, early detection, and treatment. Through use of classical and novel study designs and laboratory techniques, the Branch seeks definitive answers to significant questions regarding cancer etiology and its ultimate prevention or cure.

The Branch uses various means to achieve a better understanding of the important epidemiologic and biological issues in viral carcinogenesis. It uses its resources and experience to look ahead for new opportunities and ideas that will clarify the viral etiology of cancer. We believe that investigator initiatives, complemented by constructive internal review and extensive collaborations within and outside NCI, are critical to achieve important advances. New investigators, who range from summer students to fellows who have completed doctoral and medical specialty programs, are mentored by senior investigators, given tasks commensurate with their abilities, and strongly encouraged to develop their own research initiatives on the role of infectious agents to cancer.