The Sister Study: Genetic and Environmental Risk Factors for Breast Cancer

April 14, 2015 updated by: Dale Sandler, National Institute of Environmental Health Sciences (NIEHS)
The Sister Study is prospectively examining environmental and familial risk factors for breast cancer and other diseases in a cohort of 50,884 sisters of women who have had breast cancer. Such sisters have about twice the risk of developing breast cancer as other women.

Study Overview

Status

Completed

Conditions

Detailed Description

The Sister Study is prospectively examining environmental and familial risk factors for breast cancer and other diseases in a cohort of 50,884 sisters of women who have had breast cancer. Such sisters have about twice the risk of developing breast cancer as other women. The frequency of any relevant genes and shared risk factors will also be higher. Studying sisters enhances our ability to understand the interplay of genes and environment in breast cancer risk and to identify potentially preventable risk factors. We assess exposures before the onset of disease, thus avoiding biases common to retrospective studies. The assembled cohort has created a framework from which to test new hypotheses as they emerge.

Cancer-free sisters aged 35-74 were recruited nationally. Enrollment was completed July 2009 with 50,884 women fully enrolled. Participants have enrolled from all 50 states and Puerto Rico. The cohort is now being followed actively. Cohort members are occasionally invited to participate in add-on studies, which sometimes include asking participants to invite their family members to provide information.

Data on potential risk factors and current health status were collected with telephone interviews and self-completed questionnaires. Blood, urine, and environmental samples were collected and banked for future use in nested studies of women who develop breast cancer (or other diseases) and a sample of those who don't. The cohort is being followed prospectively for 10 or more years. Annual questionnaires update medical history and changes in exposures. About 300 new cases of breast cancer are expected to occur in the cohort each year. Analyses are ongoing and assess the independent and combined effects of environmental exposures and genetic polymorphisms that affect estrogen metabolism, DNA repair, and response to specific environmental exposures. Future analyses will focus on known and potential risk factors (e.g. smoking, occupational exposures, alcohol, diet, obesity) and include measurement of phthalates, phytoestrogens, insulin, growth factors, micro-nutrients, and genes. Women who develop breast cancer during the study are followed to assess the role of environment and genes in healthy survival following diagnosis and treatment. The cohort will also be used to explore risk for other diseases (e.g. heart disease, osteoporosis, other hormonal cancers, and autoimmune diseases) that are important for women.

Study Type

Observational

Enrollment (Actual)

50884

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • North Carolina
      • Research Triangle Park, North Carolina, United States, 27514
        • NIEHS

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

35 years to 74 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Description

Inclusion Criteria:

Women who are eligible for the Sister Study:

  • Have a sister (living or deceased) who had breast cancer
  • Ages 35-74
  • Never had breast cancer themselves
  • Live in the United States

The Sister Study is currently recruiting sisters of women diagnosed with breast cancer nationwide.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Institute of Environmental Health Sciences (NIEHS)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2003

Primary Completion (Actual)

August 1, 2009

Study Completion (Actual)

April 1, 2015

Study Registration Dates

First Submitted

October 23, 2002

First Submitted That Met QC Criteria

October 23, 2002

First Posted (Estimate)

October 24, 2002

Study Record Updates

Last Update Posted (Estimate)

April 15, 2015

Last Update Submitted That Met QC Criteria

April 14, 2015

Last Verified

November 1, 2012

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 02-E-N-271

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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