By Barbara Pierce
One in eight women in the U.S. will develop breast cancer over her lifetime. Your individual risk depends on several things: family history, pregnancy history, ethnicity, and age (the younger you are, the lower the risk.)
There’s no sure way to prevent breast cancer. But you may be doing things that increase your chances of developing breast cancer. Lower your risk by changing the risk factors that are under your control.
Risk factors for breast cancer, from Kim McMahon of the American Cancer Society, (ACS) Northeast Region:
Drinking alcohol is clearly linked to an increased risk of breast cancer. The risk increases with the amount of alcohol consumed. Women who have one drink a day have an up to 10% increase in risk; women who have two-three drinks a day have about a 20% higher risk. (A drink is defined as eight ounces of beer, one ounce of hard liquor, a small glass of wine.)
Smoking can cause a significant increased risk of breast cancer, especially in women who started smoking during adolescence or who have a family history of the disease.
Being overweight or obese after menopause increases breast cancer risk. Before menopause, your ovaries make most of your estrogen, and fat tissue makes only a small part of the total amount. After menopause (when the ovaries stop making estrogen), most of a woman’s estrogen comes from fat tissue. Having more fat tissue after menopause can raise estrogen levels and increase your chance of getting breast cancer. (A body mass index of 25 or above is considered overweight.)
Not being physically active: Evidence is growing that regular physical activity reduces breast cancer risk, especially in women past menopause. Some studies have found that even as little as a couple of hours a week might be helpful, although more seems to be better.
Not being pregnant: Women who never been pregnant or were first pregnant after age 30 have a slightly higher breast cancer risk overall. Having many pregnancies and becoming pregnant at an early age reduces breast cancer risk.
Birth control: Some birth control methods use hormones, which might increase breast cancer risk. Most studies have found that women using birth control pills have a slightly higher risk of breast cancer than women who have never used them. Once the pills are stopped, this risk seems to go back to normal within about 10 years.
Hormone therapy after menopause: Hormone therapy with estrogen (often combined with progesterone) has been used for many years to help relieve symptoms of menopause. After about four years of use, the use of combined hormone therapy does increase the risk of breast cancer. Studies of the use of estrogen alone after menopause have had mixed results, with some finding a slightly higher risk and some finding no increase. If it does increase the risk, it’s not by much.
Assessing your risk: Your health care provider can help you determine your risk of breast cancer; several risk assessment tools are available to help estimate a woman’s breast cancer risk. You can estimate your risk with an online assessment tool. These tools give approximate estimates of breast cancer risk based on different combinations of risk factors.
Screening: Whether you have risk factors or not, it’s important to get screening mammograms. The goal of screening is to find the cancer before it causes symptoms (like a lump that can be felt). When found early, breast cancer is easier to treat. Getting regular screenings is the most reliable way to find it early.
Recommendations from the ACS for screenings in women who have an average risk for breast cancer:
All women should know how their breasts normally look and feel and report any changes to a healthcare provider right away.
Women ages 40-44 should have the choice to start annual breast cancer screening with mammograms if they wish to do so.
Women ages 45-54 should get a mammogram every year.
Women ages 55 and older may switch to a mammogram every two years, or continue yearly.
Screenings should continue as long as she is in good health.
Women who are at high risk for breast cancer should get a breast MRI and a mammogram every year, typically starting at age 30, continuing as long as she is in good health.
If you are at increased risk for breast cancer (for instance, because you have a strong family history of breast cancer or have a known gene mutation that increases breast cancer risk) there are things you can do that might help lower your chances of developing breast cancer.
Genetic counseling and testing for breast cancer risk (if it hasn’t been done already)
Close observation to look for early signs of breast cancer
Medicines to lower breast cancer risk
Preventive (prophylactic) surgery
Discuss with your health care provider which, if any, of these options might be right for you.
It’s a myth:
Antiperspirants don’t cause breast cancer: Internet and e-mail rumors have suggested that chemicals in underarm antiperspirants are absorbed through the skin, interfere with lymph circulation, and cause toxins to build up in the breast, eventually leading to breast cancer.
Studies have found no connection between personal care products and breast cancer.
Underwire bras don’t cause cancer: Internet and e-mail rumors and at least one book have suggested that bras cause breast cancer by obstructing lymph flow, leading to a buildup of toxins in your breasts.
There is no scientific evidence for this claim. Researchers found no association between wearing a bra with or without underwire and breast cancer.
Induced abortion does not cause cancer: Several studies have provided very strong data that induced abortions or spontaneous abortions (miscarriages) do not have an effect on the risk of breast cancer