WASHINGTON -- A national study to explore the links between biological
sisters, environmental factors and breast cancer is seeking volunteers
among American Indian and Alaska Native women.
The "Sister Study" is a long-range research project to learn how
environmental and genetic causes affect a woman's chance of getting breast
The landmark study is being conducted by the National Institute of
Environmental Health Sciences, one of the National Institutes of Health
within the U.S. Department of Health and Human Services.
The institute began recruiting women of all races for the study last year.
Over the next three years, 50,000 women who are cancer-free, but whose
sisters have or had breast cancer, will be asked to join the project. It is
the largest study of its kind to look at breast cancer risk factors.
"American Indian and Alaska Native sisters have powerful information to
share with the Sister Study," said Sara Williams, a spokesman for NIEHS's
Survey and Epidemiology Services Division.
"Breast cancer is the second-leading cause of cancer death among American
Indian and Alaska Native women. In recent years, their rate of death due to
the disease has risen in certain areas of the U.S., and the five-year
survival rate is lower than for white women. Yet scientists have very
little information on cancer histories in American Indian and Alaska Native
communities," Williams said.
The call for volunteers comes during October -- which is also National
Breast Cancer Awareness Month. It will be followed in November by American
Indian Heritage Month.
"We want to be sure that Native women across the country know about this
study," Williams said.
Women of all backgrounds and ethnic groups are eligible for the study if
they are between the ages of 35 and 74; live in the United States; have
never had breast cancer themselves; and have a sister -- living or deceased
-- who has had breast cancer.
To recruit a diverse group of volunteers and to ensure the results benefit
all women, researchers are especially encouraging -- in addition to
American Indian and Alaska Natives -- black, Latina, and Asian-American
women, as well as women 60 and older, to join the Sister Study.
Sisters may be the key to unlocking breast cancer risk mysteries, said Dale
Sandler, chief of the Epidemiology Branch at NIEHS and principal
investigator of the Sister Study.
"By studying sisters, who share the same genes, often had similar
experiences and environments, and are at twice the risk of developing
breast cancer, we have a better chance of learning what causes this
disease. That is why joining the Sister Study is so important."
The designers of the study expect sisters of cancer victims to be highly
motivated, and therefore expect high levels of response rates and
compliance over time.
The milestone study will follow the volunteers for 10 years and compare
those who develop breast cancer with the majority who do not. While past
studies have largely focused on hormones, reproductive health and
lifestyle, the Sister Study will take the most detailed look ever at how
women's genes, and things women come in contact with at home, at work and
in the community, may influence breast cancer risk.
"Genes are important, but they don't explain it all. The truth is that only
half of breast cancer cases can be attributed to known factors," Sandler
said. And two known genes linked to breast cancer -- called BRCA 1 and BRCA
2 -- play a role in only 5 to 10 percent of cases.
The researchers believe the study will enhance their ability to identify
potentially preventable risk factors before the onset of the disease, and
thereby avoid biases that commonly creep into retrospective studies.
The Sister Study opened in pilot states, including Arizona, Florida,
Illinois, Missouri, North Carolina, Ohio, Rhode Island and Virginia, in
2004. Partner organizations include the American Cancer Society, Sisters
Network Inc., the Susan G. Komen Breast Cancer Foundation and the Y-ME
National Breast Cancer Organization, as well as countless local community
breast cancer support and advocacy groups.
To volunteer or learn more about the Sister Study, visit
www.sisterstudy.org; call toll-free (877) 474-7837; deaf or hard of hearing
can call (866) TTY-4747.