If you have a family history of breast cancer, it’s only natural to worry about your chance of developing the disease. You may even fear that a diagnosis is inevitable, especially if your family history of breast cancer (or other cancers) is strong.
But the reality is that you’re not totally powerless—and a diagnosis isn’t inevitable. Most women diagnosed have no family history of breast cancer at all, and hereditary breast cancers tied to genetic mutations are rare.
There are many steps you can take to potentially reduce your risk of breast cancer. Read on to learn how experts determine a person’s odds of developing the disease based on family health history and the risk-reduction strategies they may recommend.
While family history is a major risk factor for breast cancer, the significance of that risk varies from person to person. There are multiple parameters that help your doctor determine how likely you are to develop breast cancer when you have a family history. Examples include:
Some women carry inherited genetic mutations—BRCA1 and BRCA2 are the best known—that put them at a very high risk of what’s known as hereditary breast cancer. Only an estimated five to 10 percent of all breast cancers are thought to be hereditary and caused by gene mutations. Most women, even those with a family history of breast cancer, do not carry these mutations.
Your doctor may use one of several tools to calculate your risk of breast cancer and genetic mutations that can cause hereditary breast cancer based on your personal and family health history, such as the Manchester Scoring System, Pedigree Assessment Tool, and FHS-7. Other risk assessment tools, such as the Tyrer-Cuzick model, developed by BCRF investigator Dr. Jack Cuzick, and the Breast Cancer Risk Assessment Tool (Gail model) include other breast cancer risk factors such as age at first menstrual period and a person’s history of breast biopsies.
Once the results are complete, he or she will assign you to one of three categories of risk: average, moderate, or strong. If you’re at average risk, that means your chance of developing breast cancer is similar to the general population risk. An example of someone at average risk based on family history is a woman with one second-degree female relative with breast cancer (in one breast only) diagnosed after age 50.
If you’re at moderate risk, it means you have a somewhat higher risk of breast cancer compared to the general population. However, most women who fall into this category never develop hereditary breast cancer. Genetic counseling and testing typically isn’t recommended for this group unless the person has Ashkenazi or Eastern European Jewish ancestry. Some women with moderate risk may be screened earlier and/or more frequently for breast cancer.
Those at strong risk have a much higher risk of breast cancer, though not everyone in this category will get it. If your risk is strong, your doctor will likely recommend you undergo genetic counseling and testing, and potentially other interventions like stepped-up breast screening and preventive surgery.
Even though family history is a non-modifiable risk factor for breast cancer, there are steps you can take to lower your chance of developing the disease. Depending on your degree of risk, your doctor may suggest one or more of the options below.
Experts recommend that everyone follow healthy habits below to lower their chance of getting breast cancer, regardless of whether they have a family history.
Maintain a healthy weight. Premenopausal women who are overweight or obese are 0.8 times as likely to develop breast cancer compared to those at a healthy weight, and risk is even higher for those who are postmenopausal (1.2 to 1.4). But if you can lose the excess weight, your risk drops. And it’s never too late to reap the benefits: Women over the age of 50 were less likely to be diagnosed with breast cancer if they lost weight and kept it off, according to a study co-authored by BCRF researcher Dr. Walter Willett.
Follow a healthy diet. While there is no such thing as a “breast cancer prevention diet,” eating a plant-based diet may help lower your risk. Aim to eat more vegetables, fruit, and whole grains and less meat.
Exercise regularly. In a study published in the European Journal of Cancer, the most physically active of the female participants had a 12 to 21 percent lower risk of breast cancer than those who were least physically active. How much is enough exercise is enough to make an impact? The American Cancer Society recommends that adults get at least 150 to 300 minutes of moderate intensity or 75 to 150 minutes of vigorous intensity activity each week (or a combination of these), preferably spread throughout the week. Aim to reach or exceed 300 minutes for maximum benefits.
Limit or stop drinking. Even drinking small amounts of alcohol—a known carcinogen—increases breast cancer risk. Studies show that the more alcohol women drink, the higher their risk. Women who have one drink a day (defined as moderate consumption) have a 7–10 percent increase in risk compared to non-drinkers, while those who consume 2 to 3 drinks a day have about a 20 percent higher risk. (One drink is defined as 12 ounces of beer, 5 ounces of wine, and 1.5 ounces of liquor.) Read more about the alcohol and breast cancer connection here.
Quit smoking. You may know that smoking increases your chances of getting breast cancer, but results of a 2022 study published in Breast Cancer Researchsuggest that the risk is even greater among women with a family history of breast cancer. If you’re struggling to quit the habit, talk to your doctor about smoking cessation methods, such as counseling and medication.
Breastfeed if possible. Studies show that breastfeeding your children reduces your risk of breast cancer, especially if you can do it for at least one year. You’ll get the most benefit if you nurse for more than two years, regardless of whether those years are spent nursing one child or are the total number of years spent breastfeeding.
Limit hormone replacement therapy (HRT). Some types of HRT can increase your chance of developing breast cancer, though the significance of the risk varies depending on several factors, including how long you use it and the dose your take. And for many women, the risks outweigh the benefits. If you have a family history of breast cancer and you’re concerned about using HRT, talk to your doctor about whether it’s a safe for you.
Women found to be at high risk of breast cancer due to a strong family history of the disease and/or a genetic mutation may need more frequent screening than those with no family history or mutations. Your doctor will develop a personalized screening plan for your situation, which may include getting a mammogram every year. Supplemental screenings, such as MRI or whole breast ultrasound (WBUS ), may also be recommended because they provide more detailed images of breast tissue.
You might also need to start screening early. Most major health organizations recommend getting your first mammogram at age 40, but if you’re at high risk of breast cancer, you may benefit from starting screening at age 30 or younger.
Preventive therapy, or chemoprevention, is an option for those at strong risk of breast cancer in addition to recommended screening. There are two types of risk-reducing medication, which work by blocking estrogen in the body:
Selective estrogen receptor modulators (SERMs). The SERMs tamoxifen and raloxifene can cut the risk of breast cancer by about 40 percent. They work by blocking estrogen, which can fuel the growth of breast cancer cells. Both drugs are FDA approved to reduce the risk of breast cancer in women with higher-than-average risk. However, raloxifene is only approved for postmenopausal women, while tamoxifen is approved for both pre- and postmenopausal women. SERMs may not be recommended if you have a history of blood clots.
Aromatase inhibitors (AIs). Large studies have shown that the AIs anastrozole and exemestane can lower the chance of developing breast cancer in some post-menopausal women who are at increased risk of the disease. While they’re not FDA approved for this purpose, doctors do prescribe them to certain patients, such as those who have a history of blood clots and therefore shouldn’t take tamoxifen or raloxifene.
If your risk of hereditary breast cancer is very strong, your doctor may suggest preventive surgery (or prophylactic surgery.) The most common procedure used—a bilateral risk-reducing mastectomy—has been shown to cut the risk of developing the disease by 90 percent in women with a strong family history of the disease. In this procedure, your surgeon may perform a total mastectomy—meaning the nipple and areola are removed—or a nipple-sparing mastectomy, which preserves the nipple and areola. Both are highly effective, but a total mastectomy provides slightly more protection.
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Breast cancer prevention: aromatase inhibitors. (n.d.). American Cancer Society. https://www.cancer.org/cancer/types/breast-cancer/risk-and-prevention/aromatase-inhibitors-for-lowering-breast-cancer-risk.html
Breast cancer prevention: tamoxifen and raloxifene. (n.d.). American Cancer Society. https://www.cancer.org/cancer/types/breast-cancer/risk-and-prevention/tamoxifen-and-raloxifene-for-breast-cancer-prevention.html
Breast cancer screening. (2023, June 26). Cancer.gov. https://www.cancer.gov/types/breast/patient/breast-screening-pdq
Jones, M. E., Schoemaker, M. J., Wright, L. B., Ashworth, A., & Swerdlow, A. J. (2017). Smoking and risk of breast cancer in the Generations Study cohort. Breast Cancer Research, 19(1). https://doi.org/10.1186/s13058-017-0908-4
Khan, M., & Chollet, A. (2021, January 1). Breast cancer screening: common questions and answers. AAFP. https://www.aafp.org/pubs/afp/issues/2021/0101/p33.html
Physical activity and cancer fact sheet. (2020, February 10). Cancer.gov. https://www.cancer.gov/about-cancer/causes-prevention/risk/obesity/physical-activity-fact-sheet
Surgery to reduce the risk of breast Cancer fact sheet. (2024, June 26). Cancer.gov. https://www.cancer.gov/types/breast/risk-reducing-surgery-fact-sheet#:~:text=The%20main%20type%20of%20surgery%20to%20reduce%20breast,nipple-sparing%20mastectomy%2C%20which%20preserves%20the%20nipple%20and%20areola.
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