Sister Study seeks breast cancer’s unknown causes

Dixon says those numbers need to go up.

“Because the study is focused on women who have not been diagnosed with breast cancer, it is sometimes challenging to get them to understand why it is important to participate in the study,” says Dixon. “It’s really important to think about participation in medical research as being a part of prevention, just like getting a mammogram and just like going to the doctor to get your annual exams.”

That focus on women who have not developed breast cancer makes the Sister Study unique. Dixon says most breast cancer research has been conducted using women who have already been diagnosed.

“By the time a woman is diagnosed with breast cancer, her body has already been changed by the disease and she’s probably made lifestyle and dietary adjustments,” says Dixon. “So it’s hard to determine what happened before she was diagnosed.”

Researchers believe there is much more to be learned about what causes breast cancer; fewer than 20 percent of women who get breast cancer have a family history of the disease, according to Dixon, and only about 50 percent of those who develop it fit into traditional categories of known causes.

“You can’t find a cure unless you know what is causing the disease,” says Johnson.

Or unless researchers have relevant data. Dixon, an African American, points out that much of what is now known about breast cancer comes from studies that included mostly white participants, and that information is not as effective when trying to treat African American women.

“We will never learn what causes breast cancer in women of color if we’re not well represented in the Sister Study,” she says.

Johnson enrolled in the study four years ago. She received a start-up kit in the mail that included a questionnaire for her to fill out and materials for her to use in collecting samples of her urine, toenail clippings and house dust. After she’d done that, an examiner visited her place to take her baseline measurements and blood pressure.

Now Johnson’s only responsibility is to check in with researchers once a year and give general health information, an annual update she will provide for 10 to 14 years. Once enough women enroll, the study will begin analyzing the data gleaned from participants over that span — including which participants developed breast cancer and which ones didn’t.

While less than one in five women who develop breast cancer have family histories, it is still a significant risk factor worth studying, according to Dixon .

“Because [women with sisters diagnosed with breast cancer] have high risk of developing the disease, we know that over the course of 10 years, some of these women will develop breast cancer and others won’t,” she says. “So the goal of the study is to compare the information from those women who do develop breast cancer to the information we’ve collected from the women who don’t.”

For her part, Johnson says her lifestyle didn’t change much after she found out about her sister’s breast cancer. But if the study points out new risk factors in the future, she says she would adapt.

“I’m not sure I am doing anything wrong versus what [my sister] did,” she says.

For now, she says she makes sure to eat vegetables and fruits of different colors, tries to keep red meat at a minimum and looks to add more fish to her meals.

“We know that a lot of what we eat makes us unhealthy, and what we eat is usually what we were taught to eat as little kids,” says Johnson.

Johnson has learned from her family experience that breast cancer can have a significant impact on a woman’s self-esteem, her self-image and her interaction with the outside world.

“Breast cancer tends to be one of the worst things to affect women. It seems to cause, in many ways, more trauma,” she says. “It affects your relationships. When you have to worry about [things like] ‘Should I let them remove my whole breast?’ That is a traumatic thing … If you should have a new relationship with a man, do you share that ahead of time?”

If the study can find enough women to get involved, Dixon says, women may not have to go through such painful experiences in the future. Doctors and researchers may be able to find better treatments, or even a cure.

“Women should consider participating in breast cancer research even if they have not been diagnosed, because this information will be used to develop information that will help us prevent breast cancer in the future,” says Dixon.

Dixon’s drive to spread the word about research and prevention is a family matter, too — one born after witnessing the great-aunt, who helped raise her, battle breast cancer and succumb in 1991.

“I developed a passion for this work after I realized [I had] someone living in our family who basically didn’t talk about the fact that she had breast cancer until it was too late,” she says.

“If you care about your daughters and your granddaughters, take action now, so they won’t have to face breast cancer.”

The Sister Study is seeking African American, Latina, Asian, Pacific Islander and Native American women between the ages of 35 and 74, as well as Caucasian women between the ages of 65 and 74 with a high school degree or less. For more information, call 1-877-4SISTER (1-877-474-7837) or visit www.sisterstudy.org.