In a video of a panel conversation taped in 2014 at Memorial Sloan Kettering Cancer Center in New York, four breast cancer experts discussed the risk factors that cause the disease. One of the experts, Dr. Larry Norton, deputy physician-in-chief for breast cancer programs at MSKCC, related the story of an active man he met who claimed that by getting up early and running 15 miles per day, eating right, skipping alcohol and cigarettes and keeping his weight in check, he had significantly lowered his risk of developing cancer. The man told Norton that “if people lived like me, they wouldn’t have to worry about cancer.” Norton’s response may have been a bit surprising: “You’ve given a lot of good reasons why you’ve dramatically increased your risk of getting cancer … because you’re not going to get a heart attack first.”
As Norton’s anecdote indicates, the biggest risk factor for developing any type of cancer is age. Or more specifically, longevity; the longer you live, the greater your chances of developing cancer. This is in part thanks to medical advances that are helping us live longer while avoiding other diseases that might have felled our ancestors.
[See: 7 Surprising Things That Age You.]
Nevertheless, breast cancer is a common disease, and age and sex are the primary risk factors for developing it. The National Cancer Institute reports that 12 percent of women born in the U.S. today will develop breast cancer at some point in their lives, with the vast majority of those cases occurring in women over the age of 50. The median age at diagnosis is 62. The American Cancer Society reports that fewer than 5 percent of women diagnosed with breast cancer are younger than 40. Bottom line: The older you get, the higher your risk. And wish as we might, there’s simply nothing that can be done to slow down the march of time.
Another uncontrollable risk factor for developing breast cancer is genetic predisposition. The Centers for Disease Control and Prevention reports that women who have “inherited changes [mutations] to certain genes, such as BRCA1 and BRCA2” have an increased risk of developing breast cancer. A woman who has a strong family history of breast cancer or has previously had breast cancer herself is also at higher risk.
Along with those genetic predispositions, individual variations in the age at onset of menstruation and menopause can also affect a woman’s chance of developing breast cancer. The Centers for Disease Control and Prevention notes that women who began menstruating prior to age 12 “are exposed to hormones longer, raising the risk for breast cancer by a small amount.” Starting menopause after age 55 also means a higher risk because of longer exposure to estrogen. Similarly, taking birth control pills, getting pregnant later in life or not getting pregnant at all can slightly increase a woman’s chance of developing the disease.
Breast density has also been implicated as a risk factor for developing breast cancer. In brief, some women have dense breasts that make it harder to detect precancerous lesions and tumors on a mammogram. These growths may develop into full-blown breast cancer before they’re caught.
[See: Which Medical Screenings Should You Have in 2017?]
Although many factors that affect breast cancer risk are outside your control, it’s not all doom and gloom. “From a public health point of view, we want to minimize everyone’s risk, and there are things you can do” to achieve that aim, Norton says.
One simple way you can exercise a measure of control over your chances of getting sick is by, well, exercising. The American Cancer Society reports that studies have shown regular exercise can lower a woman’s risk for developing cancer by up to 25 percent. One study they cite showed that walking briskly for 1.25 to 2.5 hours per week was enough to lower a woman’s risk by 18 percent, and the more women walked, the more their risk dropped. The CDC recommends 150 minutes of moderate exercise per week to reduce cancer risk.
How does this work? The Susan G. Komen organization reports that exercise can lower estrogen levels in some women, which may account for some of the reduced risk. Exercise also gives your immune system a boost, which can help it fight off cancer cells naturally. Women who exercise regularly are also less likely to be overweight or obese — both risk factors for breast cancer. Controlling your weight, especially after menopause, has been linked with reduced risk of developing breast cancer, the CDC reports, and the NCI notes that the connection between exercise and lowered risk is stronger in postmenopausal women than younger women.
[See: 14 Ways Alcohol Affects the Aging Process.]
In addition, controlling your diet, making sure you’re getting enough rest and limiting alcohol intake can all reduce your risk for developing breast cancer. Dr. Parvin Peddi, assistant clinical professor in the division of Hematology and Oncology at the David Geffen School of Medicine at UCLA in Los Angeles, says, “We generally counsel women to keep it to less than three drinks a week.” So as much as a nightly glass of wine might help you relax, it’s best to tipple in moderation.
Lastly, avoiding certain drug therapies may help reduce your risk. Peddi says using hormone replacement therapy can sharply increase a woman’s risk for developing breast cancer. “A lot of people used it when they went through menopause,” but she says “most people don’t have to. If they have the option, they should stay away from it. A lot of breast cancers are dependent on hormones to feed them,” and using HRT’s mix of estrogen, progesterone, progestin and possibly testosterone to ease the unpleasant aspects of menopause can actually feed the fire of breast cancer. Norton agrees, saying, “hormone replacement therapy has absolutely been proven to be dangerous. That I think is a real ‘no-no.'”
Concerned? The National Cancer Institute offers an online breast cancer risk assessment tool that may help you better understand your individual risks.
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What Factors May Increase My Risk of Breast Cancer? originally appeared on usnews.com
