Over decades of research, experts have helped us understand more about breast cancer risk. It’s not always simple, and a person’s risk level can depend on a combination of things they are born with, lifestyle choices, social disparities and exposures in our environment. The good news? Knowing your risk factors can improve your screening and care, which may mean cancer is caught early – when it is the most treatable. Some risk factors can even be eliminated completely.
Factors that increase risk and can’t be changed:
- Age: Risk increases significantly after age 50, although Black and Hispanic women have higher rates of breast cancer in their 40s than white women.
- Sex assigned at birth: Women are at much higher risk than men.
- Genetic mutations: Genetics can impact your risk. Testing has come a long way and there are now a large panel of known genes that can increase risk, not just the well-known BRCA 1 & 2 genes.
- Family history: First-degree relatives with breast, ovarian, endometrial, or colon cancer.
- Personal history: Previous breast cancer or certain benign breast conditions.
- Reproductive history: Early menstruation (getting periods before you’re 12 years old) or late menopause (a55).
- Dense breast tissue: Increases risk and makes mammogram detection harder.
- Radiation exposure: Especially before age 30.
- DES exposure: If your mother took the medication diethylstilbestrol when she was pregnant with you.
Risk factors we can look at and work on:
- Smoking
- Obesity after menopause
- Physical Inactivity: Aim for 30 minutes, 5 times per week or a total of 150 minutes per week.
- Alcohol consumption: There is no known safe amount of use, but lower exposure = less risk.
- Hormone therapy: Long-term use of estrogen + progesterone after menopause.
- Birth control pills: Newer research suggests limited lifetime risk, if any, but risk may be higher with progestin-only pills.
- Reproductive history: First pregnancy after 30, no history of breastfeeding.
- Overnight shift work: Although this has the least causative research, there is ongoing study into why serious and long-term sleep disruption may increase breast cancer risk.
Environment
Fear mongering over what’s in our food, clothes and personal care products is everywhere. Harmful misinformation has made folks afraid to eat certain fruits, wear deodorant, and more! The good news is that most chemicals that are strongly linked to breast cancer are industrial chemicals. Unless you work in certain industries or live in specific areas, the likelihood of continued and significant exposure is low.
Early exposure: For example, in utero (in the womb).
Long-term exposure: Such as working with a risky chemical or living near a chemical site.
Industrial chemical exposure: DDT, PCBs, PFAS.
Racial disparities in breast cancer – why are Black women 40% more likely to die?
Although White and Hispanic women are more likely to develop breast cancer overall, Black women who do develop breast cancer may be more likely to die from breast cancer. Here are some of the differences that Black women may face:
- Younger age impact: Among women under 50, Black women have double the mortality rate compared to white women. Screening guidelines have only recently changed to include this lower age range (40-50). Insurance companies now must cover screening based on updated age guidelines.
- Type of breast cancer: Black women are 2.7 times more likely to develop triple-negative breast cancer (TNBC), an aggressive subtype of cancer that doesn’t respond to hormone therapy. Even within favorable subtypes, Black women still experience worse survival outcomes.
- Healthcare access: Black women are more likely to be uninsured or underinsured, and live farther from high-quality treatment centers. Because of this, Black women are less likely to receive mammograms in facilities with advanced technology, and often get screened later, when the disease has already progressed.
- They face delays in diagnosis and treatment, and are less likely to receive timely follow-up after abnormal screenings.
- Socioeconomic factors like financial stress, transportation issues, childcare responsibilities, and work constraints often derail treatment.
- Structural racism and implicit bias in healthcare settings can affect the quality of care received.
What you can do today
Evaluate your risk: Online or with your provider, check your risk status every year. This will help you get the best annual screening possible.
Lifestyle changes: Whether it’s quitting smoking or getting in more physical activity, consistent lifestyle changes have a huge impact.
Genetic Counseling: Based on your personal and family risk factors, you may want to consider meeting with a genetic counselor, and further genetic testing. The more information you have about your health, the better!
Know your body and talk to your healthcare provider about any changes or concerns.
Sources
- Niemeyer Hultstrand, Jenny et al. Hormonal contraception and risk of breast cancer and breast cancer in situ among Swedish women 15–34 years of age: A nationwide register-based study The Lancet Regional Health – Europe, Volume 21, 100470
- Boyd NF, Guo H, Martin LJ, Sun L, Stone J, Fishell E, Jong RA, Hislop G, Chiarelli A, Minkin S, Yaffe MJ. Mammographic density and the risk and detection of breast cancer. N Engl J Med. 2007 Jan 18;356(3):227-36. doi: 10.1056/NEJMoa062790. PMID: 17229950.
- Megdal SP, Kroenke CH, Laden F, Pukkala E, Schernhammer ES. Night work and breast cancer risk: a systematic review and meta-analysis. Eur J Cancer. 2005 Sep;41(13):2023-32. doi: 10.1016/j.ejca.2005.05.010.
- Murphy Lam Yim Wan, Vanessa Anna Co & Hani El-Nezami (2022) Endocrine disrupting chemicals and breast cancer: a systematic review of epidemiological studies, Critical Reviews in Food Science and Nutrition, 62:24, 6549-6576
- Lui, H et al. Endocrine-disrupting chemicals and breast cancer: a meta-analysisFront. Oncol., 08 November 2023. Sec. Breast Cancer Volume 13 – 2023 | https://doi.org/10.3389/fonc.2023.1282651
- Giaquinto, A.N., Sung, H., Miller, K.D., Kramer, J.L., Newman, L.A., Minihan, A., Jemal, A. and Siegel, R.L. (2022), Breast Cancer Statistics, 2022. CA A Cancer J Clin, 72: 524-541. https://doi.org/10.3322/caac.21754
