Biography
Dr. Morton received a B.A. in 1999 from Dartmouth College and a Ph.D. in Epidemiology in 2004 from Yale University, with a focus on cancer epidemiology. She subsequently joined the Hormonal and Reproductive Epidemiology Branch in DCEG as a Post-Doctoral Fellow and became a Research Fellow in 2005. During her doctoral and postdoctoral training, she concentrated her research on the etiology of lymphoid neoplasms and broadened her training in molecular epidemiology. When Dr. Morton became a tenure-track Epidemiologist in the Radiation Epidemiology Branch in 2008, she expanded her research to the study of multiple primary cancers, including investigation of late effects from radiotherapy and chemotherapy, as well as shared risk factors for multiple primary malignancies. Dr. Morton’s research has been recognized both within the NIH by the NCI Career Development Innovation Award and the NIH Fellows Award for Research Excellence, as well as in the greater research community by the Lymphoma Foundation of America’s 2006 Young Scientist Award and the American Association for Cancer Research Scholar-in-Training program.
Research Interests
Etiology of lymphoid neoplasms
Non-Hodgkin lymphoma (NHL) comprises a group of closely related yet heterogeneous diseases, each characterized by the malignant transformation of lymphoid cells but with distinctive morphologic, immunophenotypic, genetic, and clinical features. The strongest known NHL risk factor is severe immunodeficiency, but the etiologies of most lymphomas remain unknown. Understanding patterns of etiologic heterogeneity among NHL subtypes may illuminate mechanisms of lymphomagenesis. I have therefore focused my research on elucidating environmental and genetic risk factors for lymphoma by disease subtype.
I am a Steering Committee member for the NCI-SEER NHL Case-Control Study, a multi-center, population-based study of 1321 NHL cases and 1057 controls that includes detailed interview data, biospecimens, and environmental samples. We have recently conducted the first comprehensive assessment of risk factor patterns for the major NHL subtypes using both environmental and genetic risk factor data collected in the study. Currently, we are using the candidate gene approach to identify common genetic variants in relation to both NHL susceptibility and survival, focusing on key genes in cell cycle control, DNA repair, and immune function pathways that likely contribute to lymphomagenesis. In recent years, gene expression profiling has strongly suggested that molecularly distinct disease entities with divergent clinical behavior exist within the current histologic categories of NHL. Therefore, we are also conducting interdisciplinary molecular studies utilizing the paraffin-embedded tumor tissue collected for the cases.
I am also a member of the Pathology and Environmental/Behavior Working Groups of the International Lymphoma Epidemiology Consortium (InterLymph). The goal of the consortium is to enhance collaboration among epidemiologists studying lymphoma, provide a forum for the exchange of research ideas, and create a framework for collaborating on analyses that pool data from multiple studies. In a pooled dataset of approximately 6500 cases and 8500 controls, we reported the most conclusive evidence to date on the increased risk of follicular lymphoma associated with smoking, and decreased risk of most NHL subtypes associated with alcohol consumption. These projects and others within InterLymph highlighted the need for standardizing the definition of lymphoma subtypes in epidemiologic research. I therefore collaborated with the InterLymph Pathology Working Group, an international team of pathologists and epidemiologists, in the development of a proposed nested classification of lymphoid neoplasms to facilitate the analysis of lymphoma subtypes in epidemiologic research. This classification is already in use in multiple pooled analyses within InterLymph, as well as in numerous other case-control and cohort studies. Currently, I am collaborating within the consortium on pooled analyses of gene-environment interactions and evaluations of risk factors for rare lymphoma subtypes.
Multiple primary cancers
In 2003, REB investigators together with international collaborators launched a multi-center study of second primary gastrointestinal cancers among survivors of Hodgkin lymphoma and cancers of the testis, breast, and cervix. The study consists of two components. First, four international population-based cohorts including over 900,000 1-year survivors of Hodgkin lymphoma and cancers of the testis, breast, and cervix were assembled. The purpose of these cohorts was to evaluate site-specific second cancer incidence and trends in cause-specific mortality. Analyses of these cohorts have newly quantified the age and temporal patterns of risk for subsequent cancer and non-cancer outcomes, and highlighted that many of the excess risks often persist for over 25 years following the first cancer diagnosis. Second, in order to evaluate in detail the radiation dose-response relationship for cancers in three gastrointestinal organs (stomach, esophagus, and pancreas), a nested case-control design was chosen, resulting in a total of seven case-control studies: Hodgkin lymphoma followed by stomach, pancreas, and esophagus cancers; testis cancer followed by stomach and pancreas cancers; breast cancer followed by esophagus cancer; and cervical cancer followed by stomach cancer. For all cases and controls in the studies, detailed information was abstracted from medical records. Data collection is nearly complete, and I am helping to launch the analytic efforts.
Keywords
Non-Hodgkin lymphoma; neoplasms, second primary; neoplasms, radiation-induced; genetic susceptibility.
Selected Publications
- Morton LM, Zheng T, Holford TR, Holly EA, Chiu BCH, Seniori Costantini A, Stagnaro E, Willett EV, Dal Maso L, Serraino D, Chang ET, Cozen W, Davis S, Severson RK, Bernstein L, Mayne ST, Dee FR, Cerhan JR, Hartge P. Alcohol consumption and risk of non-Hodgkin lymphoma: a pooled analysis from the InterLymph consortium. Lancet Onco 2005;6:469-76
- Morton LM, Wang SS, Devesa SS, Hartge P, Weisenburger DD, Linet MS. Lymphoma incidence patterns by WHO subtype in the United States, 1992-2001. Blood 2006;107:265-76
- Morton LM, Schenk M, Hein DW, Davis S, Zahm SH, Cozen W, Cerhan JR, Hartge P, Welch R, Chanock SJ, Rothman N, Wang SS. Genetic variation in N-acetyltransferase 1 (NAT1) and 2 (NAT2) and risk of non-Hodgkin lymphoma. Pharmacogenet Genomics 2006;16:537-45
- Cerhan JR, Wang SS, Maurer MJ, Ansell SM, Geyer SM, Cozen W, Morton LM, Davis S, Severson RK, Rothman N, Lynch CF, Wacholder S, Chanock SJ, Habermann TM, Hartge P. Immunogenetic predictors of survival in follicular lymphoma. Blood 2007; 109:5439-46, Epub 2007 Feb 27
- Morton LM, Turner JJ, Cerhan JR, Linet MS, Treseler PA, Clarke CA, Jack A, Cozen W, Maynadie M, Costantini AS, Rudiger T, Scarpa A, Zheng T, Weisenburger DD. Proposed classification of lymphoid neoplasms for epidemiologic research from the International Lymphoma Epidemiology Consortium (InterLymph). Blood 2007; 110:695-708. Epub 2007 Mar 27
- Willett EV, Morton LM, Hartge P, Becker N, Boffetta P, Cerhan JR, Chiu BCH, Cocco P, Cozen W, Dal Maso L, Davis S, de Sanjose S, Smedby KE, Foretova L, Holly EA, La Vecchia C, Matsuo K, Maynadié M, Melbye M, Severson RK, Spinelli JJ, Staines A, Vornanen M, Roman E, for the InterLymph Consortium. Non-Hodgkin lymphoma and obesity: a pooled analysis from the InterLymph consortium. Int J Cancer 2007; Dec 31 [Epub ahead of print]
Collaborators
DCEG Collaborators
- Neil E. Caporaso, Stephen J. Chanock, Nilanjan Chatterjee, Joanne S. Colt, Rochelle E. Curtis, Susan S. Devesa, Eric A. Engels, Ethel S. Gilbert, Patricia Hartge, Ruth A. Kleinerman, Qing Lan, Ola Landgren, Martha S. Linet, Mark Purdue, Preetha Rajaraman, Nathaniel Rothman, Sholom Wacholder, Sophia S. Wang, Shelia H. Zahm.
Other NCI Collaborators
Louis M. Staudt, M.D., Ph.D. (Metabolism Branch, Center for Cancer Research)
Other Scientific Collaborators
- James R. Cerhan, M.D., Ph.D. (Mayo Clinic College of Medicine, Rochester, MN)
- Wendy Cozen, D.O., M.P.H., University of Southern California, Los Angeles, CA
- Bhavana J. Dave, Ph.D., F.A.C.M.G., University of Nebraska, Omaha, NE
- Scott Davis, Ph.D., M.S., Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA
- Graca M. Dores, M.D., M.P.H., VA Medical Center, Oklahoma, OK
- Elizabeth A. Holly, Ph.D., M.P.H., University of California at San Francisco, San Francisco, CA
- Eric J. Holowaty, M.D., F.R.C.P.C., M.Sc., Cancer Care Ontario, Toronto, Ontario, Canada
- Heikki Joensuu, M.D., Ph.D., Helsinki University Central Hospital, Helsinki, Finland
- Froydis Langmark, M.D., Cancer Registry of Norway, Oslo, Norway
- Charles F. Lynch, M.D., M.S., Ph.D., University of Iowa, Iowa City, IA
- Vishala T. Neppalli, M.D., University of Iowa, Iowa City, IA
- Richard K. Severson, Ph.D., Karmanos Cancer Institute, Wayne State University, Detroit, MI
- Hans H. Storm, M.D., Danish Cancer Society, Copenhagen, Denmark
- Marilyn Stovall, Ph.D., University of Texas M.D. Anderson Cancer Center, Houston, TX
- Mohammad A. Vasef, M.D., University of New Mexico, Albuquerque, NM
- Dennis D. Weisenburger, M.D., University of Nebraska, Omaha, NE
