Understanding your personal breast cancer risks

287,850 women are expected to be diagnosed with invasive breast cancer, and another 51,400 diagnosed with non-invasive breast cancer in 2022.¹ Additionally, more than 2,700 men in the US will develop breast cancer this year.²

Fortunately, early diagnosis and advancements in treatment have enhanced a person’s chances of survival, with more than 3.8 million breast cancer survivors alive in the US today.¹

There are several risk factors that increase your risk of developing breast cancer. 

Lifestyle risk factors 

• Limit alcohol intake – the more alcohol you drink, the higher your risk. 
• Maintain a healthy weight – it is beneficial to maintain a healthy weight throughout your entire life, but your risk of developing breast cancer increases more if you gain weight after menopause. 
• Be physically active – Studies have shown that women who participate in regular exercise have a 10-20% lower risk of developing breast cancer.^1-7 
• Consider non-hormonal therapy options after menopause – Some hormonal replacement therapies taken during or after menopause over the course for five or more years may increase your risk. Additionally, some birth control pills have also been found to increase your risk. 
• Reproductive factors – Studies have shown that delivering your first child before 30 years old and breastfeeding decreases your risk of developing breast cancer. However, you should feel confident in the decisions you make surrounding pregnancy and breastfeeding, no matter what path you decide. 

Risk factors that you cannot change:

• Aging – As you get older, your risk of developing breast cancer increases. Most breast cancers are diagnosed after the age of 50.
• Genetic mutations and family history – Some women inherit the BRCA1 and BRCA2 gene mutations, which increase your risk. You are also more likely to develop breast cancer if there is an immediate family history of breast or ovarian cancers. 
• Personal history of breast cancer – If you had breast cancer before, you are at risk of getting it a second time.  
• Dense breasts – The denser your breasts are, the higher your risk of developing breast cancer.
• Previous radiation therapy treatment – Your risk of developing breast cancer is higher if you had radiation therapy to the chest or breast for other diseases before you turned 30. 
• Diehylstillbestrol (DES) exposure – If you have taken DES, or if your mother took DES while pregnant with you, you may be at a higher risk of developing breast cancer. DES is a drug that was given to women in the United States between 1940 and 1971 to prevent miscarriage. 

Risk factors for males

Risk factors for men developing breast cancer include:

• Aging – As you get older, your risk of developing breast cancer increases. Most breast cancers in men are diagnosed after the age of 60. 
• Genetic mutations and family history – Some men inherit the BRCA1 and BRCA2 gene mutations, which increase your risk. 
• Conditions or diseases that increase female hormones – When a male is born with more than one copy of the X chromosome, they can get the genetic Klinefelter’s syndrome, which causes abnormal testicle development. Because of this, they produce higher levels of estrogen, which increases their risk. Some liver diseases also increase female hormones. Additionally, testicle disease, such as orchitis, or even surgery to remove a testicle, can increase the risk of developing breast cancer.
• Obesity – It is beneficial to maintain a healthy weight since obesity causes higher levels of estrogen. 

It is important to know that having a risk factor for breast cancer doesn’t mean that you will definitely get it, but it makes it more likely. Talk to your doctor about your personal risk of developing breast cancer and actions you can take to reduce your chances. 

1. Eliassen AH, Hankinson SE, Rosner B, Holmes MD, Willett WC. Physical activity and risk of breast cancer among postmenopausal women. Arch Intern Med. 170(19):1758-64, 2010.
2. Hildebrand JS, Gapstur SM, Campbell PT, Gaudet MM, Patel AV. Recreational physical activity and leisure-time sitting in relation to postmenopausal breast cancer risk. Cancer Epidemiol Biomarkers Prev. 22(10):1906-12, 2013.
3. Pizot C, Boniol M, Mullie P, et al. Physical activity, hormone replacement therapy and breast cancer risk: A meta-analysis of prospective studies. Eur J Cancer. 52:138-54, 2016.
4. Gong Z, Hong CC, Bandera EV, et al. Vigorous physical activity and risk of breast cancer in the African American breast cancer epidemiology and risk consortium. Breast Cancer Res Treat. 159(2):347-56, 2016.
5. Neilson HK, Farris MS, Stone CR, Vaska MM, Brenner DR, Friedenreich CM. Moderate-vigorous recreational physical activity and breast cancer risk, stratified by menopause status: a systematic review and meta-analysis. Menopause. 24(3):322-344, 2017.
6. Cifu G, Arem H. Adherence to lifestyle-related cancer prevention guidelines and breast cancer incidence and mortality. Ann Epidemiol. 28(11):767-773, 2018.
7. Guo W, Fensom GK, Reeves GK, Key TJ. Physical activity and breast cancer risk: results from the UK Biobank prospective cohort. Br J Cancer. 122(5):726-732, 2020.