Know Your Risk: Family History, Genetic Testing, and What BRCA Results Mean

When someone is diagnosed with breast cancer, one of the first questions their family members ask is: does this mean I’m at risk too? It’s a reasonable question, and it deserves a clear answer. But the relationship between family history, genetics, and breast cancer risk is more nuanced than most people realize, and the fear of what you might find out can be just as paralyzing as not knowing at all.

This post is designed to help you understand what hereditary breast cancer actually means, what genetic testing can and cannot tell you, and what to do with the information once you have it. Risk is not destiny. Knowing where you stand is a tool, not a verdict, and it’s one that can meaningfully shape the decisions you make about your health going forward. As always, this is general education. Your provider and a genetic counselor are the right people to interpret your personal risk.

How Much of Breast Cancer Is Actually Hereditary?

This is where the conversation should start, because the assumption that breast cancer is primarily a genetic disease is one of the most common misconceptions in cancer awareness.

The reality is that only about 5% to 10% of breast cancers are considered hereditary, meaning they’re driven by an inherited gene mutation passed from parent to child. The vast majority of breast cancers, roughly 85% to 90%, occur in women with no family history of the disease at all. These cases are considered sporadic, caused by acquired genetic changes that happen over a lifetime rather than mutations present from birth.

This distinction matters because it shapes how you should think about your own risk. Having a family member with breast cancer does increase your statistical likelihood, but it does not mean a diagnosis is inevitable. And not having a family history does not mean your risk is zero.

What the numbers actually tell us:

• About 85% to 90% of breast cancers are not hereditary and occur in women with no significant family history
• Having one first-degree relative (mother, sister, daughter) with breast cancer roughly doubles your risk compared to the general population, but your absolute risk may still be relatively low
• Risk increases further when multiple relatives on the same side of the family have been diagnosed, particularly at younger ages
• Male breast cancer in the family is also a relevant factor, as it can indicate the presence of BRCA mutations
• Inherited mutations account for a meaningful minority of cases, but lifestyle, environment, hormonal factors, and age play a larger role in overall breast cancer incidence

Understanding this context helps you approach genetic testing from a grounded place rather than an anxious one. The question isn’t whether your family history guarantees anything. It’s whether your history suggests that additional information could help you and your provider make better screening and prevention decisions.

What Are BRCA1 and BRCA2 in Plain Terms?

BRCA1 and BRCA2 are genes that every person has, regardless of sex. Their job is to produce proteins that help repair damaged DNA in your cells. When these genes are functioning normally, they act as tumor suppressors, helping prevent cells from growing and dividing in uncontrolled ways.

A BRCA mutation means that one copy of the gene has a change in its DNA sequence that prevents it from doing its repair work properly. When the body’s ability to fix DNA damage is compromised, the risk of certain cancers, including breast and ovarian cancer, increases significantly.

Key facts about BRCA1 and BRCA2:

• Everyone has these genes. BRCA stands for BReast CAncer gene. Having the gene is normal. Having a harmful mutation in the gene is what elevates risk.
• Mutations are inherited. A BRCA mutation is passed from parent to child. If one of your parents carries a mutation, you have a 50% chance of inheriting it.
• BRCA1 and BRCA2 are different genes with different risk profiles. Women with a BRCA1 mutation have an estimated 55% to 72% lifetime risk of developing breast cancer. For BRCA2, the estimate is 45% to 69%. These are significantly higher than the general population risk of about 13%, but they are not certainties.
• Men can carry and pass on BRCA mutations too. A father with a BRCA mutation can pass it to his children. Male carriers also have an elevated risk of breast cancer, prostate cancer, and other cancers, though the absolute numbers are lower than for women.
• BRCA mutations also affect ovarian cancer risk. BRCA1 carriers have a 39% to 44% lifetime risk of ovarian cancer. BRCA2 carriers have a 11% to 17% risk. This is why genetic counseling for BRCA often addresses both cancers together.

It’s also worth noting that BRCA1 and BRCA2 are not the only genes associated with hereditary breast cancer. Other genes, including PALB2, ATM, CHEK2, and TP53, can also carry mutations that affect breast cancer risk, though generally to a lesser degree. A comprehensive genetic test may evaluate multiple genes, not just BRCA.

Who Is Typically a Candidate for Genetic Counseling?

Genetic testing for breast cancer risk is not recommended for everyone. It’s most useful when your personal or family history suggests a pattern that could indicate a hereditary mutation. Genetic counseling is the first step in the process, and a counselor can help you determine whether testing is appropriate and what it could realistically tell you.

Factors that may indicate a referral for genetic counseling:

• A first-degree relative diagnosed with breast cancer before age 50
• Multiple relatives on the same side of the family with breast cancer, ovarian cancer, or both
• A relative with cancer in both breasts (bilateral breast cancer)
• A male relative diagnosed with breast cancer
• A known BRCA or other hereditary mutation in the family
• Ashkenazi Jewish ancestry, which carries a higher prevalence of specific BRCA mutations
• A personal history of breast cancer diagnosed at a young age or triple-negative breast cancer diagnosed before age 60
• A family history of ovarian cancer at any age

A genetic counselor will review your family history in detail, assess whether testing is likely to provide actionable information, and explain what the possible outcomes mean before you decide whether to proceed. This pre-test counseling is an important part of the process because it ensures you’re prepared to interpret the results, whatever they turn out to be.

If you’re unsure whether your family history warrants a conversation, bring it up at your next routine appointment. Your provider can help you assess whether a referral to genetic counseling makes sense based on your specific circumstances.

What Does a Positive, Negative, or Uncertain Result Mean?

Genetic test results fall into three categories, and each one requires a different response. Understanding what they mean before you’re looking at your own report helps you process the information more clearly.

Positive result

A positive result means that a harmful (pathogenic) mutation was identified in one of the genes tested. This confirms that you carry a hereditary mutation associated with increased cancer risk. 

A positive result does not mean you will develop cancer. It means your risk is elevated compared to someone without the mutation, and it opens the door to enhanced screening, risk-reduction strategies, and informed decision-making with your medical team.

A positive result also has implications for your biological relatives. Siblings, children, and parents may want to consider testing to determine whether they carry the same mutation.

Negative result

A negative result means no harmful mutations were identified in the genes tested. If you were tested because a known mutation exists in your family and your result is negative, that’s a true negative. It means you did not inherit the specific mutation your family carries, and your risk is closer to that of the general population.

If no known mutation exists in your family and your result is negative, the interpretation is less straightforward. It’s possible that a hereditary factor exists but wasn’t detected by the current test, or that the cancer in your family is not driven by a detectable genetic mutation. Your genetic counselor will help you understand what a negative result means in your specific context.

Variant of uncertain significance (VUS)

This is the result that causes the most confusion. A VUS means that a genetic change was found, but there isn’t enough scientific evidence yet to determine whether it’s harmful or harmless. It’s not a positive result, and it’s not a negative one. It’s an open question.

VUS results are more common than many people expect, and they can be frustrating because they don’t provide a clear answer. The standard recommendation is to treat a VUS as a negative result for clinical decision-making while the variant continues to be studied. Over time, as more research data becomes available, a VUS may be reclassified as either benign or pathogenic. 

Your genetic counselor may recommend periodic check-ins to see if the classification has been updated.

How Can Results Change a Screening Plan?

One of the most practical reasons to pursue genetic testing is that the results can directly influence the type and frequency of breast cancer screening you receive. For women who carry a BRCA mutation or other high-risk genetic finding, the standard screening recommendations shift significantly.

How a positive result may affect your screening plan:

• Earlier screening start. Women with BRCA mutations are often recommended to begin breast MRI screening at age 25 and mammography at age 30, rather than the standard recommendation of age 40.
• More frequent imaging. High-risk screening protocols typically alternate between mammography and breast MRI every six months, so you’re being screened every six months rather than every one to two years.
• Supplemental imaging. Breast MRI is often added to the screening plan because it’s more sensitive than mammography in detecting cancers in dense breast tissue, which is more common in younger women.
• Risk-reduction conversations. Your provider may discuss medications (such as tamoxifen or raloxifene) that can lower breast cancer risk, or surgical options (such as prophylactic mastectomy) that can significantly reduce risk for high-risk carriers. These are deeply personal decisions that should be made with a full understanding of benefits, risks, and alternatives.
• Ovarian cancer screening. Because BRCA mutations also affect ovarian cancer risk, your provider may recommend additional monitoring or risk-reduction strategies for ovarian cancer as well.

For women whose results are negative or who have a VUS, screening recommendations generally follow the standard guidelines based on age and other risk factors. But even a negative result in the context of a strong family history may lead your provider to recommend enhanced screening as a precaution.

The point is that genetic information gives your medical team a more complete picture of your risk profile, which allows them to tailor your screening plan rather than relying solely on population-level guidelines. For a detailed look at what preventive steps and screening checkpoints look like on an annual basis, The Pink Jet’s breast health checklist walks through the essentials.

How Do You Start the Family History Conversation?

Gathering your family health history is one of the most valuable things you can do before a genetic counseling appointment, and it’s something you can start today without any medical involvement. But for many families, these conversations don’t happen naturally. Cancer diagnoses may have occurred decades ago, in generations where the disease wasn’t discussed openly, or in family branches you’re not in regular contact with.

How to approach the conversation:

• Start with what you know. Write down any cancer diagnoses you’re already aware of in your family, including the type of cancer, the age at diagnosis, and which side of the family (maternal or paternal) the person is on.
• Ask both sides. BRCA mutations can be inherited from either parent, so your father’s family history is just as relevant as your mother’s. This is a detail that’s often overlooked.
• Be specific when you ask. Instead of “has anyone in our family had cancer,” ask about breast cancer, ovarian cancer, pancreatic cancer, and prostate cancer specifically, as these are the cancers most commonly associated with BRCA mutations.
• Note ages at diagnosis. Younger age at diagnosis is one of the strongest indicators of hereditary risk, so knowing whether a relative was diagnosed at 38 versus 68 is significant information.
• Include male relatives. Male breast cancer is rare in the general population but more common in BRCA carriers. If a male relative has been diagnosed, that’s important information to share with your provider.
• Don’t worry about gaps. If parts of your family history are unknown, that’s okay. Share what you have. A genetic counselor can work with incomplete information and help you assess whether what you do know is enough to warrant testing.

The goal isn’t to diagnose anything from the kitchen table. It’s to gather the information your provider needs to assess whether genetic counseling is a worthwhile next step for you.

Map Your History and Bring It In

Understanding your genetic risk starts with a conversation, first with your family, then with your provider. You don’t need to have all the answers before you walk into that appointment. You just need to bring what you know and be willing to ask the questions.

If this post helped you understand the landscape, save it for reference. And if someone in your life has been wondering whether their family history means something, send it their way. The information isn’t a reason to worry. It’s a reason to get informed.

At The Pink Jet, we believe that early detection starts with understanding your own risk. Through aviation, we bring breast cancer awareness to audiences across the country, using a striking pink L-39 Albatros aircraft and an inspiring team of female pilots to spark conversations, support survivors, and raise funds for research and advocacy organizations.

Visit thepinkjet.org to learn more about upcoming events, explore resources, and discover how you can help take the fight against breast cancer to new heights.