Lindsay M. Morton, Ph.D.

Senior Investigator

Radiation Epidemiology Branch


9609 Medical Center Drive
Room SG/7E454
Rockville, MD 20850


Research Topics

Second cancers

In recent decades, new treatments and early detection have dramatically improved cancer survival. However, second cancers are a leading cause of morbidity and mortality among survivors. In 2003, REB investigators, together with international collaborators, launched a multi-center study of gastrointestinal (GI) cancers (stomach, pancreas, esophagus) among survivors of Hodgkin lymphoma and cancers of the testis, breast, and cervix. Dr. Morton now serves as the Principal Investigator for the study.

The initiative is made up of seven case-control studies of over 800 cases and 1500 controls. Investigators abstracted detailed treatment information from medical records, and estimated radiation doses to the GI organs with individualized radiation dosimetry. The study represents the first comprehensive effort beyond the atomic bomb survivor studies to quantify the radiation dose-response relationship for upper-GI cancers, and it is one of few studies to quantify chemotherapy-related solid tumor risks. The study also includes four international population-based cohorts including over 900,000 1-year survivors of Hodgkin lymphoma and cancers of the testis, breast, and cervix for site-specific second cancer incidence and trends in cause-specific mortality. From analyses of these cohorts researchers have newly quantified the age and temporal patterns of risk for subsequent cancer and non-cancer outcomes. In addition, they have noted that excess risks often persist 25 years or more following the first cancer diagnosis.

Treatment-related myelodysplasia and leukemia is a rare but highly fatal complication of radiotherapy and cytotoxic chemotherapy that appears in the years immediately following treatment. Expanding on her expertise and long-standing interest in hematopoietic malignancies, Dr. Morton is investigating the feasibility of launching a new research project investigating leukemia risks associated with current treatments and genetic susceptibility.

Although treatments for first primary cancer are an important cause of subsequent malignancy, many second cancers are likely caused by shared environmental and genetic risk factors. Historically, studies of second cancers have relied on historical medical records, with limited information on additional risk factors. Dr. Morton and collaborators are developing novel strategies for studying second cancers. For example, they are pilot testing an effort to pool data from existing epidemiologic cohort studies to evaluate second cancer risks associated with lifestyle, environmental, and genetic factors.

Etiology of lymphoid neoplasms

Non-Hodgkin lymphoma (NHL), the sixth most common cancer in the United States, comprises a group of closely related yet heterogeneous diseases. Because understanding differences in risk among NHL subtypes may illuminate mechanisms of lymphomagenesis, Dr. Morton’s research is focused on investigating environmental and genetic risk factors for lymphoma by disease subtype.

The International Lymphoma Epidemiology Consortium (InterLymph), initiated in 2001, comprises international investigators who have completed or are conducting ongoing case-control studies of NHL. Dr. Morton led the InterLymph Pathology Working Group efforts to develop a nested classification of lymphoid neoplasms for epidemiologic research. This classification has been adopted by InterLymph, numerous case-control and cohort studies, and the SEER Cancer Statistics Review. Dr. Morton is now leading a consortium-wide effort to comprehensively understand patterns of numerous risk factors across both common and rare NHL subtypes. She also collaborates on a number of other InterLymph projects, including an ongoing genome-wide association study to identify genetic susceptibility to NHL.

In addition to InterLymph, Dr. Morton is also collaborating on a number of studies of patients with HIV/AIDS or who received a solid organ transplant, since individuals with severe immunosuppression have strikingly increased risk for hematologic malignancies.


Dr. Morton received a B.A. from Dartmouth College and a Ph.D. in Epidemiology from Yale University with a focus on cancer epidemiology. She then joined DCEG’s Hormonal and Reproductive Epidemiology Branch as a Postdoctoral Fellow and became a Research Fellow. During her doctoral and postdoctoral training concentrated in molecular epidemiology, she focused her research on understanding the causes of lymphoid neoplasms.

In 2008, Dr. Morton joined the Radiation Epidemiology Branch (REB) as a tenure-track investigator. She expanded her research to the study of multiple primary cancers, evaluating the carcinogenic effects of radiotherapy and chemotherapy, as well as other environmental and genetic risk factors for second cancers. In 2015, Dr. Morton was awarded scientific tenure by NIH. Dr. Morton has been recognized for her research contributions with the NCI Career Development Innovation Award, the NIH Fellows Award for Research Excellence, and the Lymphoma Foundation of America’s Young Scientist Award.

Selected Publications

  1. Morton LM, Dores GM, Curtis RE, Lynch CF, Stovall M, Hall P, Gilbert ES, Hodgson DC, Storm HH, Johannesen TB, Smith SA, Weathers RE, Andersson M, Fossa SD, Hauptmann M, Holowaty EJ, Joensuu H, Kaijser M, Kleinerman RA, Langmark F, Pukkala E, Vaalavirta L, van den Belt-Dusebout AW, Fraumeni JF Jr, Travis LB, Aleman BM, van Leeuwen FE. Stomach cancer risk after treatment for hodgkin lymphoma. J Clin Oncol. 2013;31(27):3369-77.

  2. Lamart S, Stovall M, Simon SL, Smith SA, Weathers RE, Howell RM, Curtis RE, Aleman BM, Travis L, Kwon D, Morton LM. Radiation dose to the esophagus from breast cancer radiation therapy, 1943-1996: an international population-based study of 414 patients. Int J Radiat Oncol Biol Phys. 2013;86(4):694-701.

  3. Morton LM, Dores GM, Tucker MA, Kim CJ, Onel K, Gilbert ES, Fraumeni JF Jr, Curtis RE. Evolving risk of therapy-related acute myeloid leukemia following cancer chemotherapy among adults in the United States, 1975-2008. Blood. 2013;121(15):2996-3004.

  4. Wong JR, Morton LM, Tucker MA, Abramson DH, Seddon JM, Sampson JN, Kleinerman RA. Risk of subsequent malignant neoplasms in long-term hereditary retinoblastoma survivors after chemotherapy and radiotherapy. J Clin Oncol. 2014;32(29):3284-90.

  5. Morton LM, Slager SL, Cerhan JR, Wang SS, Vajdic CM, Skibola CF, Bracci PM, de Sanjosé S, Smedby KE, Chiu BC, Zhang Y, Mbulaiteye SM, Monnereau A, Turner JJ, Clavel J, Adami HO, Chang ET, Glimelius B, Hjalgrim H, Melbye M, Crosignani P, di Lollo S, Miligi L, Nanni O, Ramazzotti V, Rodella S, Costantini AS, Stagnaro E, Tumino R, Vindigni C, Vineis P, Becker N, Benavente Y, Boffetta P, Brennan P, Cocco P, Foretova L, Maynadié M, Nieters A, Staines A, Colt JS, Cozen W, Davis S, de Roos AJ, Hartge P, Rothman N, Severson RK, Holly EA, Call TG, Feldman AL, Habermann TM, Liebow M, Blair A, Cantor KP, Kane EV, Lightfoot T, Roman E, Smith A, Brooks-Wilson A, Connors JM, Gascoyne RD, Spinelli JJ, Armstrong BK, Kricker A, Holford TR, Lan Q, Zheng T, Orsi L, Dal Maso L, Franceschi S, La Vecchia C, Negri E, Serraino D, Bernstein L, Levine A, Friedberg JW, Kelly JL, Berndt SI, Birmann BM, Clarke CA, Flowers CR, Foran JM, Kadin ME, Paltiel O, Weisenburger DD, Linet MS, Sampson JN. Etiologic heterogeneity among non-Hodgkin lymphoma subtypes: the InterLymph Non-Hodgkin Lymphoma Subtypes Project. J Natl Cancer Inst Monogr. 2014;2014(48):130-44.

This page was last updated on December 6th, 2016