Lymphoma Epidemiology of Outcomes (LEO) Study

The Lymphoma Epidemiology of Outcomes (LEO) Study is a multicenter, prospective cohort study to better understand current and long-term unmet health needs of people diagnosed with non-Hodgkin's lymphoma.

Patients with a new diagnosis of non-Hodgkin's lymphoma are offered enrollment into the study. Once enrolled, participants complete questionnaires about their health history, lifestyle, quality of life and other factors.

The LEO study team abstracts clinical, pathology and treatment data from medical records. Participants also provide a blood sample, which is processed and stored in the LEO biorepository. LEO study pathologists review and classify diagnostic tumor tissue, some of which is also stored in the LEO biorepository. The LEO team then actively follows all participants over time to collect disease outcomes, new treatments and subsequent cancers (all validated), as well as updated medical and lifestyle data, patient-reported outcomes (including quality of life), and other factors potentially impacting survivorship.

Dr. Cerhan's Lymphoma Epidemiology Lab at Mayo Clinic is coordinating the study. The study is funded by the National Cancer Institute (U01 CA195568).

Visit the LEO Cohort website for more details.

Study goals

The goals of the LEO lymphoma study are to:

  • Follow patients over time to identify factors that affect outcomes and survivorship in non-Hodgkin's lymphoma
  • Improve diagnosis, risk stratification, treatment, and short-term and long-term management of patients with non-Hodgkin's lymphoma
  • Find new and better ways to improve the length and quality of life for people living with non-Hodgkin's lymphoma

The LEO lymphoma study supports a broad research agenda aimed at identifying factors that significantly influence prognosis and survivorship, including:

  • Treatment and clinical factors
  • Biologic factors, including genetics and immune and tumor factors
  • Diet and lifestyle factors
  • Environmental and chemical exposures
  • Medical history
  • Family history of cancer
  • Psychosocial factors

The first phase of LEO (LEO Phase 1, NCT02736357) enrolled 7,748 patients with newly diagnosed non-Hodgkin's lymphoma from July 2015 through May 2020. The LEO study was renewed from 2021 to 2026 to continue following up on all participants and continue targeted recruitment as LEO Phase 2 (NCT04996706).

Dr. Cerhan's lab is coordinating the LEO lymphoma study with these seven other study sites:

  • The University of Iowa
  • Emory University
  • Cornell University
  • MD Anderson Cancer Center
  • University of Miami
  • University of Rochester Medical Center
  • Washington University

Learn more about LEO Lymphoma Study participants.

Related study files

Researchers can learn more about the study by reviewing these PDF files for study news and questionnaires: