Genetics & Breast Cancer: What You Need to Know About BRCA1 and BRCA2 - Galaxy-care/blog GitHub Wiki

When we talk about breast cancer risk, family history is often one of the first things mentioned. But what does that really mean? As a breast cancer specialist, one of the most important conversations I have with patients involves understanding the role of genetics — especially the BRCA1 and BRCA2 genes.

Let’s break down what you need to know about these genes and how they influence breast cancer risk.

What Are BRCA1 and BRCA2? BRCA1 (Breast Cancer gene 1) and BRCA2 (Breast Cancer gene 2) are human genes that produce proteins responsible for repairing damaged DNA. These genes play a vital role in ensuring the stability of our genetic material. When either of these genes is mutated, DNA damage may not be properly repaired, which increases the risk of certain cancers — most notably breast and ovarian cancer.

How Do BRCA Mutations Affect Breast Cancer Risk? People who inherit harmful variants in BRCA1 or BRCA2 have a significantly higher risk of developing breast cancer:

BRCA1 mutation: Up to a 72% lifetime risk of breast cancer. BRCA2 mutation: Up to a 69% lifetime risk. Compare this to the average woman’s lifetime risk of breast cancer in the general population — about 13%.

As a breast cancer specialist, I emphasize that while these mutations don’t guarantee cancer, they do drastically increase risk, often at a younger age than average.

Who Should Consider Genetic Testing? Genetic testing for BRCA1 and BRCA2 mutations is typically recommended for:

Individuals with a strong family history of breast, ovarian, pancreatic, or prostate cancer. Women diagnosed with breast cancer under age 50. People with male breast cancer in the family. Those of Ashkenazi Jewish descent, who have a higher likelihood of carrying BRCA mutations. Individuals with multiple relatives affected by breast or ovarian cancer. If you meet any of these criteria, consult a breast cancer specialist or genetic counselor to discuss whether testing is right for you.

What Happens If You Test Positive? Testing positive for a BRCA1 or BRCA2 mutation can be overwhelming — but it also opens doors to proactive care and prevention. Options may include:

Increased screening (e.g., starting mammograms and MRIs earlier). Preventive surgeries, such as mastectomy or oophorectomy. Medications that help lower risk (chemoprevention). Lifestyle modifications and personalized surveillance plans. As a breast cancer specialist, my role is to help patients weigh the benefits and risks of these approaches based on personal values, age, and overall health.

How a Breast Cancer Specialist Can Help Navigating genetic risk isn’t something you should do alone. A breast cancer specialist can:

Interpret your genetic testing results. Help create a personalized prevention or treatment plan. Offer referrals to genetic counselors. Provide emotional support as you make difficult decisions. Final Thoughts Understanding BRCA1 and BRCA2 is a powerful tool in the fight against breast cancer. Genetic information, when used appropriately, allows you to take proactive steps — sometimes even before cancer ever develops.

If you’re concerned about your breast cancer risk or considering genetic testing, speak with a trusted breast cancer specialist. Knowledge is power, and early action can save lives.