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Your Environment. Your Health.

Sister Study or el Studio de Hermanas

Study / Trial Background

The Sister Study is conducted by the National Institute of Environmental Health Sciences, one of the National Institutes of Health, of the US Department of Health and Human Services. From 2004 to 2009, more than 50,000 women across the US and Puerto Rico, who were between ages 35–74 and whose sister had breast cancer, joined this landmark research effort to find causes of breast cancer. Because of their shared environment, genes, and experiences, studying sisters provides a greater chance of identifying risk factors that may help us find ways to prevent breast cancer.

The Sister Study is currently tracking the health of women in the cohort. Participants complete health updates each year, as well as detailed questionnaires about health and experiences every two-to-three years. Research in the Sister Study focuses on causes of breast cancer and other health issues in women, as well as on factors that influence quality of life and outcomes after a breast cancer diagnosis.

Eligibility Criteria

  • Ages Eligible for Study: 35–74 years
  • Genders Eligible for Study: Female
  • Accepts Healthy Volunteers: No
  • Have a sister (living or deceased) who had breast cancer
  • Never had breast cancer themselves
  • Live in the United States

Contact Information

Additional information can be found at the Sister Study website or contact:

Sister Study
Tel 877-4SISTER (877-474-7837)
For deaf or hard of hearing:
866-TTY-4SIS (866-889-4747)

Be mindful, personal information sent through email cannot be protected. 

Principal Investigator

Photo of Sandler, Dale P.
Dale Sandler, Ph.D.
Chief, Epidemiology Branch and Senior Investigator
Tel 984-287-3711
Fax 301-480-3290
P.O. Box 12233
Mail Drop A3-05
Durham, N.C. 27709
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