Discover Your Risk: Understanding Breast Cancer Genetics
Breast cancer remains one of the most common cancers worldwide, prompting many individuals to seek information about their genetic risk. This guide discusses key genetic factors linked to breast cancer and explains how you can take proactive steps toward better health.
The Basics of Breast Cancer Genetics
We All Have the BRCA1 Gene (and That’s OK)
It may surprise some to learn that every person has the BRCA1 gene, (pronounced “BRAH-kuh”) among many other genes that have been associated with cancer. The presence of these gene by itself does not mean you will develop cancer.
In fact, we all have many genes that help our bodies function, and BRCA1 is one of them. Problems arise only when there is a mutation—an alteration or change—in certain genes that disrupts their normal function.
Why It Matters
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BRCA1’s Role: When functioning correctly, the BRCA1 gene helps repair DNA breaks that can lead to cancer.
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Mutation vs. Normal Gene: Only mutated versions of BRCA1 (or other cancer-related genes) significantly increase your risk. This distinction is crucial for understanding personal health and risk factors.
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Did you know? BRCA stands for BReast CAncer gene. Both men and women can carry these genes and pass them down to children.
On The Podcast
On The Blog
Genetic testing. What exactly is it and how does it concern you? Why is it important that you get tested and why are there conflicting conversations surrounding the topic?
These were some of the questions I had walking into the podcast interview with Fatima Amir, a Genetic Counselor at Dana Farber.
Breast cancer, one of the most prevalent cancers among women, can be categorized into two main types: hereditary (or germline) and sporadic. Understanding the distinctions between these types is crucial as they differ in causes, risk factors, and implications for treatment and prevention.
After putting extra hormones in my body during the IVF process, I knew that I would always be at a higher risk for some cancers. Little did I know, that is not what was putting me at a higher risk for breast cancer and ovarian cancer.
What is a Genetic Mutation
A genetic mutation is a permanent alteration or change in the usual sequence of DNA in a gene. Think of your genes as an instruction manual. When an instruction (sequence) is out of place, it can cause an entire process in the body to go awry.
Somatic vs. Germline
Mutations
Germline mutations are inherited from a parent and are present in every cell of your body from birth.
If one parent carries a germline mutation, there is a 50% chance of passing it on to each child.
Somatic mutations happen during a person’s lifetime and are not inherited from parents. They occur in only certain cells and are usually caused by environmental factors, lifestyle factors, or random mistakes when cells divide. Somatic mutations cannot be passed on to your children.
Key Takeaways
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Not All Mutations Lead to Cancer: Many genetic changes are harmless or have minimal impact.
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High-Risk Mutations: Mutations in genes like BRCA1, BRCA2, and others can impair DNA repair, leading to an elevated cancer risk.
Breast Cancer–Related Genes
While BRCA1 is often in the spotlight, several other genes can influence your likelihood of developing breast cancer—plus, new risk-associated genes continue to be discovered. Notable examples include:
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BRCA2
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Similar in function to BRCA1; responsible for DNA repair
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Mutations can increase the risk of breast, ovarian, and prostate cancers
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TP53
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Known as the “guardian of the genome” for its role in preventing abnormal cell growth
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Mutations can lead to Li-Fraumeni syndrome, associated with multiple cancers
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PTEN
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A tumor suppressor gene linked to Cowden syndrome
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Increases risk of breast, thyroid, and endometrial cancers
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ATM
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Plays a critical role in DNA damage response
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Mutations can lead to increased breast cancer risk
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CHEK2
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Involved in cell cycle regulation
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Mutations can modestly increase breast cancer risk
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STK11
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Associated with Peutz-Jeghers syndrome
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Increases risk for breast, pancreatic, and gastrointestinal cancers
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PALB2
Carrying a hereditary cancer gene mutation can raise the likelihood of developing more than just breast cancer. Some of the cancers associated with BRCA1, BRCA2, and other related genes include:
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Ovarian Cancer
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Prostate Cancer
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Pancreatic Cancer
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Male Breast Cancer
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Melanoma
Why These Genes Matter
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Risk Assessment: Knowing whether you carry a mutation in one or more of these genes informs your breast cancer screening schedule, often leading to earlier and more frequent screening.
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Personalized Medicine: Genetic testing can guide individualized prevention and treatment strategies, such as risk-reducing surgeries, enhanced screening protocols, or targeted therapies.
Ongoing Discovery
Researchers are continually uncovering new genes associated with inherited breast cancer risk. Staying informed about the latest developments in genetic testing is especially important for individuals with a strong family history of breast or related cancers
Genetic Testing &
Counseling
If you have a strong family history of breast, ovarian, or other associated cancers, consider genetic testing. A licensed genetic counselor can guide you through:
Risk Assessment
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Reviewing personal and family medical history
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Evaluating the appropriateness of genetic testing
Types of Genetic Tests
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BRCA-only tests focus on BRCA1 and BRCA2
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Multigene panels screen for multiple genes simultaneously (BRCA, TP53, ATM, etc.)
Test Interpretation
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Understanding positive, negative, or “variant of uncertain significance” (VUS) results
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Exploring implications for family members
Action Plan
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Enhanced screening (e.g., earlier mammograms, breast MRI)
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Risk-reducing surgeries (e.g., mastectomy, oophorectomy)
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Lifestyle changes (diet, exercise, avoiding tobacco)
