BRCA2

BRCA2 is a gene that prevents and fights cancer. It’s a key tumor suppressor gene. But most people only learn about it when they find out that they have an abnormal BRCA2 gene — a mutation. Mutations in BRCA2 increase your risk of developing breast, ovarian, prostate and pancreatic cancers.

Less than 1% of people have this mutation. You can inherit it if either of your biological parents carries a copy of the faulty gene and passes it on to you. If one of your parents has the gene, there’s a 50% chance you’ll inherit it. The risk is the same no matter your sex.

Having a BRCA2 mutation doesn’t mean that you’ll get cancer. And if you do develop cancer, it doesn’t mean that it’s untreatable or incurable. In fact, having this mutation may mean you have more treatment options than someone without it.

But the BRCA2 mutation does increase your cancer risk. It increases your chances of getting a cancer diagnosis at an early age. This is why it’s important to know what having this mutation means for your health. 

Which cancers are associated with BRCA2?

In the 1990s, doctors found that mutations in the BRCA1 and BRCA2 genes increase the risk of breast and ovarian cancers. Now, we know that BRCA mutations also increase a person’s risk of prostate and pancreatic cancer. Others — like melanoma, stomach cancer and uterine cancer — may also be linked to BRCA2. But more research is needed to know for sure.

The table below compares the lifetime risk of developing these cancers in people with the mutation versus the general population.

^{Stats on general population risk from NCI; stats on BRCA2-related risk from NCCN Guidelines.}

BRCA2 and Fanconi anemia

Inheriting a BRCA2 mutation from both parents causes a form of Fanconi anemia. This rare condition increases a person’s risk of developing several types of blood disorders and cancer.

It’s very rare that both parents carry the gene. But it’s still a good idea to meet with a genetic counselor and assess the risks before trying to have a baby.

Who needs testing for BRCA2 mutations?

Your healthcare provider may suggest BRCA testing after reviewing your personal and family medical history. “Family,” in this instance, means your first- and second-degree blood relatives. First-degree relatives include your parents, siblings and children. Second-degree relatives include your grandparents, aunts and uncles. This helps providers know how likely it is that you inherited the gene.

Risk factors include:

• Being of Ashkenazi Jewish, Icelandic, African or West African descent
• Having been diagnosed with a cancer linked to the BRCA2 mutation in the past
• Having family members who were diagnosed with breast cancer before age 50
• Having many relatives on the same side of the family who’ve been diagnosed with cancer linked to the BRCA2 mutation
• Having relatives with triple-negative breast cancer, male breast cancer or high-grade prostate cancer

There are different testing options. Some test a blood sample, while others test your spit for the mutation. Often, tests check for several mutations at once to assess your cancer risk.

What does a positive BRCA2 mean? 

What your results mean depends on when you learn you have the mutated gene. For most people, that’s usually after getting their DNA test results or as part of their cancer diagnosis.

BRCA2-positive results following a DNA test

A positive result means your cancer risk is greater than in most people. Your healthcare provider will explain what this means for your health. They’ll help you understand:

• How to detect early warning signs of cancer: They may teach you to do breast self-exams at home, so you’re more likely to detect early warning signs of breast cancer.
• What cancer screenings you need: Your cancer screening schedule will look different from most people’s. You may need breast imaging starting in your 20s or 30s. You may need yearly prostate exams starting at age 40. Follow your provider’s screening plan for you.
• Surgeries for cancer prevention: There may be surgeries available to reduce your cancer risk. You may choose to have your breast tissue removed to prevent breast cancer. Having your ovaries and fallopian tubes removed prevents ovarian cancer.
• Medicines that may help: Your doctor may prescribe medicines to reduce your cancer risk. For example, medicines like tamoxifen may reduce your risk of developing breast cancer. Your provider will help you weigh benefits against potential side effects to help you decide.
• Your options for having a baby: Your provider can let you know how likely it is that you’ll pass the gene on to a child. They can suggest procedures like IVF to keep a future child from getting the gene. 
• How to inform family members: It’s important to let your relatives know that a BRCA2 mutation runs in the family. Your provider may be able to share resources you can give to them. 

​BRCA2-positive results during a cancer diagnosis

These mutations inform both your outlook (prognosis) and your treatment options.

For example, BRCA2-related breast cancers are often HR-positive (HR+). This means they grow in response to hormones. They tend to be less aggressive than some other types of breast cancer. They also respond well to treatment.

In contrast, most breast cancers linked to the BRCA1 gene are triple-negative. These tend to be aggressive.

But most BRCA2-positive prostate cancers grow and spread faster than ordinary prostate cancers.

Having this mutation often means that the cancer will respond to certain kinds of treatment. Common treatments include:

• Platinum-based chemotherapy: Chemotherapy doesn’t work on all cancers. But platinum-based chemo is usually effective if you have a BRCA2 mutation. Treatments include the drugs cisplatin, carboplatin and oxaliplatin.
• PARP inhibitors: Treatments like olaparib (Lynparza^®) block cancer cells from getting a protein they need to grow. You may get this medicine after chemotherapy to keep the cancer from coming back. Sometimes, it keeps cancer from getting worse.
• Aromatase inhibitors: These medications can treat HR+ breast cancers. Examples of these medicines include letrozole (Femara^®) and anastrozole (Arimidex^®). Most breast cancers that involve the BRCA2 mutation are HR+. 

Having the BRCA2 mutation may also impact surgeries. For instance, these breast cancers may be more likely to recur (come back) after treatment. To prevent this, your provider may recommend removing your entire breast (or both breasts) instead of just the tumor.

What can I expect if I have a BRCA2 mutation?

It varies. You can have the mutation and never develop cancer. If you do, having the BRCA2 mutation provides just one sliver of info about your diagnosis. The cancer type and stage, your age, health and treatment response are a few factors that also matter. Some BRCA2 cancers can be cured. Others are more serious. No one with a BRCA2 mutation has the same life expectancy or experience. 

On the one hand, the uncertainty can feel overwhelming. But knowing your risk can also help you take charge of your health. You can work with your healthcare provider to decide what your cancer screening schedule should be. You can also decide what steps you want to take to prevent cancer.

You may choose to have a mastectomy to reduce your breast cancer risk. You can also decide to have surgery to remove your ovaries — but delay it until after you’ve had children. You and your healthcare provider can weigh the pros and cons so that you’re doing what’s best for your health.