Lymphoma Epidemiology of Outcomes (LEO) Study

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

People with a new diagnosis of non-Hodgkin lymphoma are offered enrollment into the study. Once enrolled, they 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. Study participants also provide a blood sample, which is processed and stored in a biorepository through the Biospecimen Accessioning and Processing (BAP) Core at Mayo Clinic. LEO study pathologists review and classify diagnostic tumor tissue, some of which also is stored in the LEO biorepository.

The LEO team actively follows all participants over time to collect validated information about disease outcomes, new treatments and subsequent cancers. They also gather updated medical and lifestyle data, participant-reported outcomes, including quality of life, and other factors potentially affecting survivorship.

Dr. Cerhan's lab coordinates the study. The study is funded by the U.S. 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 participants over time to identify factors that affect outcomes and survivorship.
  • Improve diagnosis, risk stratification, treatment and short-term and long-term management.
  • Find new and better ways to improve the length and quality of life.

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

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

The first phase of LEO (LEO Phase 1, NCT02736357) enrolled 7,735 people with newly diagnosed non-Hodgkin lymphoma from July 2015 through May 2020. The LEO study was renewed in 2021 to continue targeted recruitment as LEO Phase 2 (NCT04996706) and to continue following up on all participants in MER and LEO.

Dr. Cerhan's lab coordinates the LEO lymphoma study with 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 in St. Louis.

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: