Breast Cancer Screening - Know Your Risk & What You Can Do About It
Isla Oliver, DNP, CNM, ARNP
Fall comes with many excellent reminders to be aware of our breast and chest health! Patients often come in unsure of when to start mammograms, whether their family history "counts," what screening tools they really need, or whether a medication they're taking is quietly raising their risk. I’m here to break down what the evidence actually says.
What do we look at to calculate breast cancer risk?
1. Family History – Most breast cancer is not linked to genetics.
Only about 5-10% of cases are linked to an inherited gene change, like BRCA1 or BRCA2. But if you carry one of those gene changes, your risk goes up a lot. By age 80, about 72% of BRCA1 carriers and 69% of BRCA2 carriers will develop breast cancer. Compare that to about 12-13% for the average woman. 1, 2
If your mom, sister, or child has had breast cancer — especially before age 50 — or if a relative has a known BRCA gene change, talk to your provider. This is true even if you have not been tested yourself. You may need genetic counseling or earlier screening. 3
2. Personal History – If you've had breast or ovarian cancer before, your risk of getting it again is higher than someone who hasn't.
This risk sticks around for years, not just right after treatment. A past diagnosis of atypical hyperplasia or LCIS (lobular carcinoma in situ) also raises your lifetime risk, even though neither one is cancer itself.
If any of this applies to you, you need a personalized screening plan.
3. Medication Use – Certain medications can increase your risk of breast cancer.
Combined estrogen-progestin Menopause Hormone Therapy is linked to a small rise in breast cancer risk. 4
To put the numbers in perspective: it means about one extra case for every 1,000 women who use it each year. Importantly, women in these studies were not more likely to die from breast cancer.
Estrogen-only therapy (used by women who've had a hysterectomy) has not shown this same risk increase. 4
Contraceptives (pills, patches, vaginal rings, IUDs, and implants) may slightly increase your risk of breast cancer, but that risk is small & is reversible when you stop using the medication. 9
4. Screening for “Average Risk” People – This is where the biggest recent change happened.
In 2024, the USPSTF (a national panel of health experts) updated its advice. It now recommends a mammogram every two years starting at age 40 and continuing through age 74. 5 The American Cancer Society has long said women can choose to start yearly mammograms at 40, with all women starting by 45. You can switch to every two years at 55 if you prefer. 6 The bottom line: if your risk is average, you should be discussing mammograms by your 40th birthday.
Breast exams are a hotly debated topic, with little evidence that they are helpful in finding cancer in people who don’t have symptoms. Because of this, USPSTF, American Cancer Society and the CDC no longer recommend clinical breast exams for women of average risk. 5,6 The exception would be if someone has noticed a change in breast tissue, or a lump.
It is recommended that you are familiar with, and feeling your tissue so that you would notice a change. 5,6
5. Screening for “High Risk” People – If your lifetime risk is 20% or higher
This can be calculated on your own, or with the help of a provider, by reviewing your personal & family history. If you are high risk, The American Cancer Society recommends a yearly breast MRI in addition to your yearly mammogram. MRI can catch more in this group. 7
If you've never had a real risk assessment performed by a provider, and you’re concerned you may be high risk, it only takes about ten minutes, and it can change your whole screening plan.
6. How To Reduce Your Risk.
No lifestyle change removes all risk. But a few things do lower it. These include getting at least 150 minutes of moderate exercise a week, keeping a healthy weight, having one or fewer alcoholic drinks day, and breastfeeding after pregnancy if you’re able. 8
Together, healthy habits like these are thought to prevent a large share of breast cancer cases. Add in knowing your family history, getting a risk assessment, and staying on top of screening, and you're doing what actually helps.
If you're not sure where your risk falls, that's exactly what a visit is for. Bring your family history, ask questions, and let's build a plan that fits you.
References
Kuchenbaecker KB, et al. Risks of Breast, Ovarian, and Contralateral Breast Cancer for BRCA1 and BRCA2 Mutation Carriers. JAMA. 2017.
American Cancer Society. Key Statistics for Breast Cancer.
National Cancer Institute. BRCA Gene Mutations: Cancer Risk and Genetic Testing.
Rossouw JE, et al. Risks and Benefits of Estrogen Plus Progestin in Healthy Postmenopausal Women: Women's Health Initiative Randomized Controlled Trial. JAMA. 2002.
U.S. Preventive Services Task Force. Final Recommendation Statement: Breast Cancer Screening. April 30, 2024.
American Cancer Society. American Cancer Society Recommendations for the Early Detection of Breast Cancer.
American Cancer Society Breast Cancer Advisory Group (Saslow D, et al.). American Cancer Society Guidelines for Breast Screening with MRI as an Adjunct to Mammography. CA Cancer J Clin. 2007.
American Cancer Society. Diet and Physical Activity Guideline for Cancer Prevention.
Susan G Komen. Breast Cancer Risk Factors: Birth Control Pills and Other Hormonal Birth Control. https://www.komen.org/breast-cancer/risk-factor/birth-control-pills/
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