Experts estimate that about one in eight women born in the U.S. today will be diagnosed with breast cancer. You may already know someone who is battling it. "Much of what causes breast cancer is not something that a woman has control over," says Dr. George Sledge, professor of medicine and chief of the division of oncology at Stanford. That's a scary thing to hear about a disease that kills nearly 40,000 U.S. women a year.
But there's hope: Some of what causes breast cancer can be controlled — they're what doctors call "modifiable" risk factors. By making a few positive changes now, you can lower the chance that you'll get a diagnosis. "I'm not going to say all of them are super easy, but I think they're doable," says Dr. Therese Bevers, professor of clinical cancer prevention and medical director of the cancer prevention center at M.D. Anderson Cancer Center. "And if need be, your physician can help you with resources to do them successfully."
Keep your BMI in a healthy range.
Fat cells make estrogen. The more fat you carry, the higher your estrogen levels. And the higher your estrogen levels, the higher your risk, especially in women who gain extra weight post-menopause. Of course, losing weight is easier said than done. But it's worth it, especially over a lifetime. "It's this long exposure to moderately high estrogen levels that's bad for you," says Virginia Kaklamani, co-director of the cancer genetics program and director of translational breast cancer research at Northwestern University. So keep tabs on your body-mass index and make sure it stays below 25. (Here's how to calculate your BMI.) Even being a few points over 25 can have a negative impact. "Whether you have a BMI of 28 or 30 or 40, it's the same," says Kaklamani.
2. Stay active.
Research shows that women who exercise regularly have a 25 percent lower risk of developing breast cancer compared to the most inactive women. The American Cancer Society recommends that adults do moderate-intensity exercise at least 150 minutes a week — that's just three gym classes. But you don't need to go nuts to make a positive impact: Simple activities like walking count. Researchers looked at 73,615 post-menopausal women and found that those who simply put one foot in front of the other seven hours per week — about an hour a day — had a 14 percent lower risk of breast cancer compared to their inactive peers.
More good news? You don't have to be slim to benefit from working out. "Even overweight women who exercise routinely are at lower risk of developing breast cancer," says Bevers. "[But] clearly her risk may be even lower if she, through exercise, were able to attain a healthy body weight."
3. Drink less alcohol.
The more booze you consume, the more you increase your risk. Researchers don't yet know why alcohol increases risk, but they do know "it's related to how many drinks you have," says Sledge. According to Kaklamani, "The mechanism is not clear, but usually women who drink have higher estrogen levels." Alcohol increases cholesterol, which gets converted into estrogen. Limit alcohol intake to no more than one drink a day.
4. Breastfeed if you have children.
It's good for your baby — and your breast health. "The more months you breastfeed, the lower your likelihood of developing breast cancer," says Sledge. Why? "Starting periods later, ending periods sooner, and having fewer periods because you've been breastfeeding or exercising a lot all reduce your risk," he says. It boils down to decreased exposure to estrogen.
Giving birth to your first child at a younger age also decreases the likelihood of developing breast cancer, though no one knows why. "One thought is with the first pregnancy, the breast undergoes an irreversible change that makes it less sensitive to carcinogens," says Sledge. "It might be related to the milk-producing hormone prolactin."
5. Keep hormone therapy short.
The Women's Health Initiative study showed that a combination of estrogen and progesterone increased the risk of breast cancer. If you and your doctor feel you need hormone-replacement therapy because of menopausal symptoms, take the lowest possible dose for the shortest possible time. If you're on birth control, keep in mind that taking the pill slightly increases your risk — but it seems to go back to normal over time once you stop taking the pill, according to The American Cancer Society.
6. Get regular mammograms.
While mammograms don't prevent cancer, they make a cure more possible. "You're detecting it at a stage where it's more likely to be curable," says Kaklamani. Breast cancer is curable in 90 percent of stage one cases, 80 percent of stage two cases, and 60 percent of stage three cases, she says.
The American Cancer Society recommends that women receive the low-dose x-ray procedure annually beginning at age 40. The U.S. Preventive Services Task Force, which is concerned about false positives for women in their 40s who have denser breast tissue, recommends getting them every other year beginning at age 50. Which rule should you follow? "We're approaching an area where we try to individualize," says Sledge. "Not all women should get the same diagnostic techniques." Work with your doctor to find a screening schedule that's right for your particular factors.
7. Research your family history.
Check if any family members have a history of breast and ovarian cancer — and, remember, even men can get breast cancer. If you're related to a carrier of an inherited mutation (known as BRCA1 and BRCA2), make sure to get tested. And tell your doctor if you've had any radiation exposure to the chest at a young age — another risk factor.
8. Make your doctor your ally.
Check the National Cancer Institute's Breast Cancer Risk Assessment Tool, which looks at variables such as age, time of first menstrual cycle and birth of a first child, history of first-degree relatives, and race. (For unknown reasons, white women are more likely to develop breast cancer after menopause and black women before menopause.) Then talk to your doctor to interpret the test. She may suggest specific tests and a more aggressive screening schedule. The most important thing is that you work together — and that you do what you can to reduce your modifiable risk factors. "Maintain a healthy body weight, be as active as you can be, and, if you drink alcohol, don't have more than a drink a day," says Alpa Patel, PhD., a strategic research director at The American Cancer Society.
