Preventing Breast Cancer 101

You'd think that breast cancer would be the farthest thing from a 14-year-old's mind. But nearly as soon as they grow breasts, many girls begin to fear the worst. "They are full of misinformation; they worry that being bumped in the breasts will put them at higher risk," says Marisa Weiss, an oncologist in Philadelphia whose own college-age daughter recalls that she kept her puberty-era worries under wraps. Weiss, who founded the nonprofit informational group breastcancer.org, wanted to ease girls' fears—but also to tell them how they might reduce their eventual risk of the disease. So she has been talking to them and their mothers at school assemblies over the past 18 months.

Video: What Is Breast Cancer?

Weiss's effort—which also includes a book cowritten with her daughter called Taking Care of Your "Girls"—is one of a growing number of programs that aim to educate young girls about breast cancer and how to cut the odds of getting it. All are based on research suggesting that women may be able to reduce their risk through lifestyle measures like diet and exercise, and possibly by avoiding certain environmental toxins. Howard University's Project Early Awareness targets high school students in Washington, D.C. Zero Breast Cancer, a San Rafael, Calif.-based nonprofit focusing on the environmental contributors to breast cancer, has a program, as does Chicago's Breast Cancer Network of Strength. And local affiliates of Susan G. Komen for the Cure fund similar programs nationwide.

A big part of the message is that girls' risk is vanishingly small. The odds that a 10- or 15-year-old will develop breast cancer in the subsequent decade are about 1 in 10,000. Compare that with the 244-in-10,000 odds for a 50-year-old. "We need to protect that feeling of health," says Lisa Schwartz, a faculty member at Dartmouth Medical School and codirector of the VA Outcomes Group in White River Junction, Vt. "We need to say, 'You're young and vital and healthy, and you don't really need to worry about this.'"

That said, it seems clear that in the long run, lifestyle matters. In October, a study found that for normal-weight, postmenopausal women, vigorous exercise was linked to a 30 percent decline in the chances of getting the disease. And a 2007 report found "convincing" evidence that excess body fat increases the chances of breast cancer, again in postmenopausal women. So these programs encourage girls to simply develop good lifetime habits.

There's also evidence that the pre-childbearing years have an influence on future susceptibility to cancer, at least for some women. Scientists know that the exposure to estrogen and other steroid hormones over a woman's life is a key factor, and the earlier the onset of a woman's first menstrual period, the higher her later risk of breast cancer. How to manage exposure? In May, a study suggested that getting exercise as early as age 12 can help lower the risk of premenopausal breast cancer in later life, perhaps because it lowers the amount of estrogen in the body.

Some programs, like Zero Breast Cancer's, also recommend against exposure to environmental chemicals such as bisphenol A and phthalates, found in certain plastics and personal care and household products. It's a tricky message to deliver, because there's no consensus on which products are harmful, says Charles Atkin, chair of the communications department at Michigan State University, who researches how information about breast cancer is communicated to the public. Weiss argues that it's better to be safe than sorry—and she also advises girls to avoid drinking milk from cows given hormones. Often, she says, there's an easy alternative: Eat a more plant-based diet, and use a metal water bottle rather than a hard plastic one. Weiss adds that breast education should focus on general breast health, not on teaching teenage girls to do monthly breast self-exams or to get mammograms in the future. "It's about getting to know your body," she says.

A healthful diet, exercise, and knowing your own body? Sounds like a prescription for people of any age.