Has Your Sister Had Breast Cancer?

Sister Study, a study of the environmental and genetic risk factors for breast cancer, is seeking women age 35 to 74 in the U.S. and Puerto Rico who have not had breast cancer, but whose sisters have, for a long-term national study to learn how environment and genes affect the chances of getting breast cancer.

Since its launch in October 2004, Sister Study has recruited more than 34,400 participants for the study, which is overseen by the National Institute of Environmental Health Sciences of the National Institutes of Health and the Department of Health and Human Services. NIEHS hopes to meet its enrollment goal of 50,000 women by the end of 2007.

The non-invasive study includes questions about what participants are doing now, as well as about when they were growing up, and when they were in their 20s. Some questions include, “Where have you lived the longest since age 20?,” “During the ages of 10-13, about how often did you wear make-up?,” “Before she was pregnant with you, did your mother smoke?,” and “What kinds of fat or oil do you usually use in cooking?”

“Things we already know may influence a woman’s chances of getting breast cancer — things like family history, reproductive history, age at menarche and menopause, weight, exercise — together account for less than half of breast cancer cases,” said Dale Sandler, Ph.D., chief of the epidemiology branch at NIEHS and principal investigator of the Sister Study. “Our genes influence the way we respond to exposures in our environment, which is why it is important to examine genes, personal history and exposures to things in the environment in the same study.”

The website explains how the study is conducted. Basically, a female health technician comes to your home to collect small samples of blood, urine, toenail clippings and house dust, which will also help give researchers a better picture of your environment and genes. Then, for about 10 years, Sister Study will touch base once a year to inquire about address, health or environmental changes. You won’t be asked to take any medicine or make any changes to your diet or daily life.

Meet the investigators leading the study or check out this list of frequently asked questions. Information on eligibility is available here.