Genetic Testing for Breast Cancer: Know Your Risk & Options

Genetic testing for breast cancer is not one test and not one decision. This guide walks through how to prepare, what the panel actually reads, who should be tested first in a family, how to read an uncertain result, and which separate gene tests matter once treatment starts.

Have you ever wondered why breast cancer seems to show up more in some families than others? It often comes down to something in your genes, like the basic guidebook your body follows every day. Genetic testing for breast cancer looks closely at your DNA to find any small changes that could raise your chances of getting the disease. This helps you and your doctor figure out the best ways to stay ahead of it, whether through check-ups or other steps.

From the latest guidelines by the National Comprehensive Cancer Network, people diagnosed with breast cancer at 50 or younger should get testing for changes in genes like BRCA1, BRCA2, CDH1, PALB2, STK11, and TP53. It’s a big step toward making this available to more folks who need it.

What Is Genetic Testing for Breast Cancer

A genetic test for breast cancer checks your DNA for little shifts known as mutations or harmful changes. These passed-down tweaks can make it much more likely you’ll face breast cancer at some point in life.

How the test is done:

• A small blood sample, saliva sample, or cheek swab sample is taken.
• Then sent to a genetics laboratory.
• Results typically return within 2-4 weeks, and sometimes it takes a bit longer.

Types of Test Results:

When you get your test reports from a breast cancer genetic testing panel, they fit into one of three results:

• Positive: A gene change that raises your risk of breast cancer is found
• Negative: Nothing unusual showed up in the genes they checked
• Variant of Uncertain Significance (VUS): There’s a change, but no one’s sure yet if it matters for cancer risk

Remember: A positive result does not guarantee you will develop breast cancer; it indicates a higher risk than the general population.

Key Genes Linked to Breast Cancer

BRCA1 and BRCA2: The Primary Gene

When some people talk about genes for breast cancer, they often mean BRCA1 and BRCA2. These genes help repair broken DNA. When a harmful change stops one of them from working properly, that repair work fails, damage builds up, and cells can start to grow out of control.

• Women with a shift in the BRCA gene face a much higher chance of breast cancer, plus risks for ovarian, pancreatic, or other types too. The numbers can feel heavy.
• Women with a BRCA1 or BRCA2 mutation have a much higher lifetime risk of breast cancer than the general population. The published estimates cover a wide range, so ask a genetic counselor what the current figures mean for your own situation.
• But keep in mind, only about 0.25 percent of people overall have one of these changed BRCA genes—that’s roughly one in 400.

Other Important Genes

New steps forward in genomic testing for breast cancer have pointed out more genes that play a part in raising risks:

• PALB2: Works with BRCA2 to repair damaged DNA and also increases breast cancer risk.
• PTEN: Regulates cell growth; mutations can raise cancer and non-cancer growth risks.
• TP53: Associated with multiple cancers, including breast, blood, and brain cancers.
• CDH1: Linked to lobular breast cancer and stomach cancer.
• ATM, CHEK2, STK11: Moderate increase in breast cancer risk.

Several genes beyond BRCA1 and BRCA2 are now linked to higher breast cancer risk, which is why full panel genetic testing for breast cancer is often considered instead of just checking BRCA1 and BRCA2.

Who Should Consider Genetic Testing?

Not everybody needs a genetic test for the breast cancer gene. It’s most helpful for those with certain signs in their own or family health stories.

Talk to your doctor about genetic testing for breast cancer if you have:

• Got breast cancer before turning 50
• Have triple-negative breast cancer found before 60
• Dealt with breast cancer on both sides
• Have several close family members with breast cancer, like mom, sister, or daughter
• Know of male breast cancer in the family
• Have relatives with ovarian, pancreatic, or tough prostate cancer
• Come from an Ashkenazi Jewish background (some BRCA changes are more common there)
• Have a family member known to have a BRCA or other cancer-linked change

If a parent has a BRCA mutation, there’s a 50 percent chance their children inherit it.

Note: Inherited (germline) genetic testing for breast cancer looks for gene changes you were born with. It does not report HER2 status, which is measured on the tumor tissue itself, and it is not used to choose a chemotherapy regimen. Your oncology team puts tumor testing, stage and your overall health together to plan treatment.

Understanding BRCA Testing CPT Codes

BRCA testing CPT codes are standard numbers used for billing and insurance.

Common ones are:

• CPT 81162: Full check of BRCA1 and BRCA2 genes
• CPT 81212: BRCA testing for known changes (often the Ashkenazi Jewish set)
• CPT 81432: Panel for hereditary breast cancer (covers many genes)

Diagnosis Codes: Z15.01 – Genetic susceptibility to breast cancer. Your clinic’s billing team can confirm which codes your insurer expects before the sample is collected.

Where to Get Genetic Testing for Breast Cancer

Starting the Process

Figuring out where to get genetic testing for breast cancer starts with talking to your doctor. It’s a good idea to see a counselor before and after. Counselors review family history, discuss risks, and help determine which genes to test.

Testing Locations:

You can get a genetic test for breast cancer through:

• Programs at hospitals for genetics
• Labs that do genetic work on their own
• Centers focused on cancer care
• Doctors in regular care who know genetics well

Some research studies and community health programs also offer hereditary cancer testing at little or no cost, so it is worth asking your care team whether one is enrolling in your area.

What Happens After Testing?

Understanding Your Results

After receiving your results, meet with a genetic counselor or your doctor to discuss what they mean for you and your family.

• Positive: High-risk mutation detected
• Negative: No known mutation detected
• Uncertain: Mutation found, but impact unknown

Remember:

Your DNA doesn’t change, so your test result for a specific mutation will always stay the same. What can change is how experts understand certain gene changes. A result marked “uncertain” today may be reclassified in the future as research improves.

Risk Management Options

If you’re positive for a high-risk change, there are solid ways to lower the chances:

Enhanced Screening:

• Mammograms starting sooner and more often
• Adding breast MRI to mammograms
• Breast checks by a doctor every 6 to 12 months

Preventive Medications (Chemoprevention):

• Tamoxifen or raloxifene before menopause
• Aromatase inhibitors after menopause

Risk-Reducing Surgery:

• Preventive breast removal (prophylactic mastectomy)
• Ovarian removal for BRCA carriers (prophylactic oophorectomy)

Risk-reducing surgery can lower the chance of breast cancer substantially, but it is a major and permanent decision. Work through the benefits, the limits and the recovery with your surgeon and your genetics team before choosing it.

Implications for Family Members

The results of your genetic test may also be relevant for your family members, as they could share the same gene changes. If you test positive, your siblings and children have a 50% chance of carrying the same mutation. Encourage them to consider genetic counseling and testing.

Hereditary vs. Sporadic Breast Cancer

• Hereditary Breast Cancer: Approximately 5-10% of breast cancer cases are hereditary, which means the mutational gene comes from the parents.
• Sporadic Breast Cancer: But 90-95% breast cancer cases are not inherited. These cancers usually occur due to aging, daily habits, environmental exposure, and random changes in DNA that occur naturally over a lifetime.

Research into the genetics of breast cancer continues to uncover new genes and mechanisms, which also helps doctors identify individuals at higher risk and offer more personalized care.

While RPH Labs does not offer breast cancer genetic testing, our at-home pharmacogenetic (PGx) tests provide insights into how your body processes medications, which can be crucial for personalized healthcare. You can search your gene in our platform to access relevant guidelines and CPIC publications (PMID).

Recent Advancement and Research Updates

• Expanding Testing Criteria: Wider rules for who gets tested are opening up more info on genes, making care for breast cancer more exact.
• Polygenic Risk Scores: Past just one-gene checks, experts are building polygenic risk scores that mix data from hundreds of small gene tweaks for a finer look at risks. These new scores provide additional detail to the standard genetic testing for inherited cancer risk.
• Cost Trends: Testing costs have dropped a ton. Today, comprehensive panel tests are more affordable than ever, making genetic testing accessible to a wider range of people who may benefit from it.

Information:

The American Society of Breast Surgeons now recommends that any breast cancer patient who wants genetic testing should be offered it, a major shift from older, more restrictive guidelines.

How to prepare for genetic testing for breast cancer

A little preparation makes genetic testing for breast cancer far more useful. The single most valuable thing you can bring to the appointment is a written family history, because the pattern in your family often decides which panel is ordered and whether insurance will cover it.

Before you go, try to collect the following for relatives on both sides of your family, going back to grandparents where you can:

• Who had cancer, what type it was, and the age at diagnosis.
• Any relative with cancer in both breasts, or with breast and ovarian cancer.
• Male relatives with breast cancer, and relatives with pancreatic or aggressive prostate cancer.
• Ancestry, since some variants are more common in certain populations.
• Any relative who has already had a brca gene test or a wider panel, and a copy of that report if you can get it.

Also write down what you want out of the result. Some people test to decide about screening, some to decide about surgery, some so that siblings and children have information. The reason matters, because it shapes which genes are worth reading.

Finally, ask the ordering clinic two practical questions: which laboratory the sample goes to, and what your out-of-pocket cost will be if your plan denies the claim. Most labs publish a self-pay price, and most will tell you before the sample is drawn.

What a brca gene test actually looks at

A brca gene test reads the DNA you inherited, usually from blood or saliva. It is looking for a germline change, meaning a change present in every cell of your body since conception. That is different from tumor testing, which reads the DNA of a cancer that has already formed.

Germline versus tumor testing

Both can be ordered for the same person, and they answer different questions. Germline results tell you about inherited risk and about relatives. Tumor results describe that one cancer and often guide treatment choices. If you are told you had genetic testing, it is fair to ask which of the two it was.

Modern hereditary panels read more than two genes. Alongside BRCA1 and BRCA2 they commonly include genes such as PALB2, ATM, CHEK2, TP53, PTEN, CDH1 and STK11. A panel finds more answers, but it also finds more results nobody can interpret yet, which is the tradeoff your clinician should explain up front.

Why an old negative result may need a second look

Laboratory methods have widened over time. A brca gene test from an earlier era may have read only the most common variants, or may have missed large deletions and duplications. If your testing predates current panels, ask whether an updated panel is reasonable rather than assuming the file is closed.

Why a genetic counselor belongs in the process

A genetic counselor is a clinician trained specifically in inherited risk. In practice their job is to choose the right test, explain what each possible result would mean before you consent, and then help you act on whatever comes back.

Meeting a genetic counselor before the sample is taken tends to prevent the two most common problems: the wrong person in the family gets tested, and the wrong panel gets ordered. Both are expensive mistakes to unwind.

• They translate an uncertain result, which is far more common than most people expect.
• They know which relatives should be offered testing and in what order.
• They can explain how results interact with life insurance and disability coverage, which federal employment and health insurance protections do not cover.
• They document a plan, so the result does not sit unused in a chart.

You can usually reach a genetic counselor through a cancer center, a hospital genetics program, or by telehealth, which has made access much easier outside large cities. If you are offered testing with no counseling attached, you can ask for a referral anyway.

Bring your written family history to that visit, and bring your questions. A good session is a conversation, not a lecture.

Breast cancer risk assessment beyond a single gene

Most people who develop breast cancer do not carry a high-risk inherited variant. That is why a normal result does not end the conversation, and why clinicians use a broader risk assessment alongside genetic testing for breast cancer.

A fuller assessment usually weighs several things together:

• Detailed family history, including ages at diagnosis.
• Personal history of breast biopsies and what those biopsies showed.
• Breast density reported on your mammogram.
• Reproductive and hormonal history.
• Any past chest radiation therapy, which raises risk independently of genes.

Clinicians often run these inputs through a validated risk model to estimate lifetime risk. The output is an estimate, not a prediction about you personally, and different models can give different numbers for the same person. Treat it as a way to sort screening options rather than a verdict.

The practical value is that risk assessment can qualify someone for added screening, such as breast MRI alongside mammography, even when no variant is found. That decision belongs with your clinician, who will weigh your age, your breast density and what your imaging history already shows.

Hereditary breast cancer and which relative to test first

When a family is considering testing, the order matters. In hereditary breast cancer, the most informative person to test first is usually a living relative who has already had the cancer, ideally the one diagnosed youngest.

The reason is simple. If a variant is found in that person, everyone else in the family can be tested cheaply and precisely for that one change. If an unaffected relative tests first and the result is normal, it may only mean the test was pointed at the wrong gene.

Cascade testing, step by step

1. Test the affected relative with a full hereditary panel.
2. If a clear variant is found, offer single-site testing to first-degree relatives.
3. Work outward through the family as results come in.
4. Repeat the conversation with younger relatives as they reach an age where screening decisions start.

Families rarely move through this in one sitting, and that is fine. Some relatives will not want to know, and that choice deserves respect. What helps is one person keeping a copy of the laboratory report, since relatives need the exact variant name to be tested accurately.

Hereditary breast cancer also affects men in a family. A father can carry and pass on a BRCA2 variant, and his own risks for breast, pancreatic and prostate cancer may change as a result.

Medicines during treatment: where a dpyd gene test fits

Inherited cancer risk testing and pharmacogenomic (PGx) testing are two different things. PGx does not look for cancer genes and cannot tell you whether you will develop a disease. It reads genes that control how your body processes certain medicines, which becomes relevant once treatment starts.

A dpyd gene test is the clearest example. DPYD variants reduce the enzyme that clears fluorouracil and capecitabine, two chemotherapy drugs used in several cancers. People with reduced DPYD function can experience severe toxicity at standard doses, so guidelines support testing before the first dose and adjusting with the oncologist.

• DPYD and fluorouracil or capecitabine, where a dpyd gene test may change the starting dose.
• CYP2D6 and tamoxifen, since tamoxifen needs CYP2D6 to form its active metabolite.
• UGT1A1 and irinotecan, which is used in some regimens.
• CYP2D6 and ondansetron, a common anti-nausea medicine.

Timing is the practical catch. A dpyd gene test is most useful before treatment begins, so it is worth asking about early rather than after a reaction. Published gene and drug pairs are listed by CPIC and in the FDA table of pharmacogenomic biomarkers in drug labeling.

To be clear about what RPh Labs does and does not do: our 20-gene panel includes DPYD, CYP2D6 and UGT1A1 and reports on 240+ medications, and you can see the full list on our medication list. It does not include BRCA1, BRCA2 or any other hereditary cancer gene, and it does not assess disease risk. Inherited cancer risk testing has to be arranged through your own clinician or a cancer genetics program.

Questions to ask before and after genetic testing for breast cancer

Appointments move quickly. Writing questions down ahead of time is the easiest way to leave with something usable.

Before the sample

• Which genes are on this panel, and why these genes for me?
• Is this germline testing, tumor testing, or both?
• What will I owe if my plan denies the claim?
• How long until results, and who will call me either way?
• Will a genetic counselor review the report with me?

After the result

• What exactly was found, and can I have a copy of the laboratory report?
• Does this change my screening schedule, and starting when?
• Which relatives should be offered testing, and how do I explain it to them?
• If the result is uncertain, will the laboratory contact me when it is reclassified?
• Does anything here change medicines I already take, or would take during treatment?

That last question is where a pharmacogenomic report can help, and it is a separate order from genetic testing for breast cancer. If you want to understand how PGx reports are built, our overview of what PGx testing is covers the basics, and the at-home cheek swab kit page explains how sample collection works.

Limits worth knowing before you test

Honest limits make the result easier to live with. Genetic testing for breast cancer answers a narrow question well, and says nothing at all about many others.

A normal result does not mean no risk. It means no variant was found in the genes that were read, with the methods used. Most breast cancer is not explained by a high-risk inherited variant, so screening recommendations still depend on your age, family history and imaging.

An uncertain result is not a diagnosis and is not a reason to act. Variants of uncertain significance are usually reclassified as harmless over time as laboratories gather more data. Management should be based on your family history until the laboratory says otherwise.

A variant also does not set a date. It shifts probability across a lifetime, which is why carriers are offered earlier and more intensive screening and, for some, risk-reducing options. Those choices are personal, they change with age and plans for children, and they are made with your care team over time rather than in one appointment.

And no genetic test replaces paying attention to your own body. A new lump, skin or nipple change, or persistent focal pain deserves evaluation whatever your genetic result says.

Conclusion:

Genetic testing for breast cancer can be a valuable resource in cancer prevention. If you have a family history or other risk factors that put you at increased risk, speaking to your physician about testing is important. Remind yourself that knowledge is power! Understanding your genetic risk allows you to take proactive steps toward protecting your health through improved screenings, preventive strategies, and informed decision-making.

RPH Labs remains committed to precision healthcare through our at-home PGx testing services, helping you understand how your genes influence medication responses.

Disclaimer:

This blog does not provide medical diagnosis or treatment recommendations. Always seek the advice of a licensed medical professional for health decisions. Images used in this article may be AI-generated and are shown for illustrative purposes.

Frequently Asked Question

Genetic testing for breast cancer FAQ

How do you test for the breast cancer gene?

Blood is drawn, saliva is taken, or a cheek swab is performed, and the sample is sent to a laboratory for genetic testing to look for specific breast cancer gene mutations.

Can men get genetic testing for breast cancer?

Yes! Men can get breast cancer as well, and BRCA mutations are also linked to a higher risk of pancreatic, prostate and some skin cancers. Men with BRCA mutations should undergo genetic testing and appropriate screening.

What if I had tested years ago?

Patients who had genetic testing previously may benefit from updated testing, especially if their testing occurred before 2013, when panels were much more limited.

Does a brca gene test tell me if I have cancer now?

No. A brca gene test reads inherited DNA and estimates risk. It does not detect a tumor. Finding cancer still relies on imaging such as mammography, ultrasound or MRI, plus examination and biopsy when something suspicious appears. A normal panel result does not remove the need for the screening schedule your clinician recommends.

Can I order hereditary breast cancer testing from RPh Labs?

No. The RPh Labs 20-gene panel is pharmacogenomic, which means it reports how you may process certain medicines. It does not include BRCA1, BRCA2 or other hereditary cancer genes and does not assess disease risk. Hereditary breast cancer testing is arranged through your own clinician, a cancer center or a genetics program.

How do I find a genetic counselor if my clinic does not have one?

Ask your primary clinician or oncologist for a referral to a hospital genetics program or cancer center. Many programs now offer telehealth visits, so you do not need to live near a large medical center. If testing is offered without counseling, you can still request a referral before or after the sample is collected.

Why would a dpyd gene test matter during chemotherapy?

DPYD makes the enzyme that clears fluorouracil and capecitabine. Reduced function can lead to severe toxicity at usual doses, so a dpyd gene test before the first dose lets your oncologist adjust the starting dose. It is most useful ordered early. Any dose decision belongs to the oncologist, alongside kidney and liver function and other medicines.

What happens if my result is a variant of uncertain significance?

It is treated as unresolved rather than positive. Care continues to be guided by your family history and other risk factors. Laboratories re-examine these variants as evidence accumulates, and most are eventually reclassified as harmless. Ask the laboratory and your clinic how you will be notified if the classification changes.

Do men need this testing too?

Sometimes. Men can carry and pass on variants in BRCA1, BRCA2 and other genes, and carrying one can change their own screening for breast, prostate and pancreatic cancer. If a variant is found in a family, male relatives should be offered testing as well. A genetics clinician can advise what screening, if any, follows.