Answers to common questions about the breast cancer gene

Answers to common questions about the breast cancer gene ( how it can impact your family)

By Christopher Shale, MD

Working with patients during breast reconstruction is both challenging

and rewarding. Helping women deal with a breast cancer diagnosis can be tough, but I’m continually inspired by their incredible strength and resolve.

Breast cancer patients are often mothers, and invariably their thoughts turn to protecting their families. My patients often ask, “What does this diagnosis mean for my family, my daughters?” They are concerned about passing “the breast cancer gene” to their children, but only 5-10 percent of women with breast cancer have a gene that could convey an increased risk for breast cancer. More accurately, “breast cancer genes,” when normal, can actually protect you from getting certain types of cancer. It’s when these genes mutate that there’s an increased risk of developing certain types of cancer, of which breast and ovarian cancer are the most common.

The following questions will help you understand how genetics affect breast cancer so that you and your family can find answers and stay healthy.

Who should be tested?

Specific mutations in the BRCA gene, such as BRCA 1 and BRCA 2, have demonstrated an increased risk of breast and ovarian cancer, but they are very uncommon. In the general public, it’s estimated that less than one in 400 individuals have one of these significant BRCA mutations.

As we learn more about our genetics, there are other genes that can also increase the risk of breast cancer – such as the PALB2, CHEK2, ATM, TP53, PTEN and BRIP1 genes. Studies show there are risk factors that can increase the chances of having one of these genetic mutations. However, even for people with these risk factors, only 15-20 percent will have one of these breast-cancer gene mutations. This may seem complicated, as so much of the information keeps developing and updating every year, which is why it’s important to work with a breast cancer specialist and genetic counselor, so they can help you understand whether you should be tested and what the results mean. People with any of these risk factors can be tested and have the test covered by their medical insurance – because it’s considered preventative care.

RISK FACTORS FOR BREAST CANCER GENE TESTING

A first- or second-degree relative who was diagnosed before they were age 50 with breast cancer Any male first- or second-degree relative diagnosed with breast cancer

Two or more breast cancers in the same first- or second-degree relative Two or more relatives on the same side of the family with breast cancer

Breast cancer and ovarian cancer in the same first- or second-degree relative, or in family members on the same side of the family

A family member with a “triple negative” breast cancer diagnosed before age 60

Having a first- or second-degree relative with a known mutation of BRCA

How do I get tested?

Genetic testing can be ordered by a physician, or through a genetic counselor. After reviewing your family history, the physician or counselor can decide which test would be most appropriate based on the types of cancer in the family. Sometimes they can see patterns associated with certain syndromes that can have an increased risk of breast cancer, such as Cowden or Li-Fraumeni syndrome. They can also determine who would be best to test first. Sometimes it’s better to get a family member further up the family tree who has had cancer tested first. If they don’t have the genetic mutation, it’s unlikely they passed it on. A genetic counselor or physician will also be key when reviewing genetic test results. The tests are complicated and don’t always give you a simple “yes” or “no” answer. Everyone’s genes are a little different, and we’re still learning the importance of certain genes, so there can be variances that we yet don’t know what to make of. The test result may show a variation of unknown significance that’s still “normal,” and a genetic counselor can explain these results to you.

What if I do have a harmful mutation of BRCA 1 or 2?

First, know this does not mean you will get cancer. Although the risk of developing cancer with one of these mutations is higher than in the general population, it isn’t 100 percent. The table below lists the risk for developing breast or ovarian cancer, and this information changes as data continues to come in. There are ways to decrease risks for getting cancer, and close monitoring can be done to catch cancers in an earlier stage. However, the options you choose are incredibly personal. I recently counselled a 17-yearold girl about the BRCA gene mutation and what that meant for her. This is a very different discussion from the one I have with a 60-year-old grandmother who took the test to get information to help her children. Prevention strategies can include a spectrum of options, from more frequent exams, mammograms and MRIs, medications – or surgery to remove the breast tissue and ovaries, which can dramatically reduce the risk of breast and ovarian cancer. It’s important to review these options with a physician, so you can make an informed decision that’s right for you.

RISK OF DEVELOPING CANCER BY THE AGE OF 70

Breast Cancer

Ovarian Cancer BRCA 1 72% (55-85%) 44%

BRCA 2 69% (43-84%) 17%

ASSESSING YOUR RISKS

Moderate exercise DECREASES by 15-25%

Breastfeeding DECREASES risk of breast cancer

Alcohol

Estrogen/progesterone hormone replacement therapies

Tobacco >3 or 4 drinks per week INCREASES risk by 15%

Use of HRT INCREASES risk by 25%

INCREASES risk of breast cancer

Obesity

Radiation INCREASES risk of breast cancer

INCREASES risk of breast cancer

If I don’t have the BRCA mutation, does that mean I can’t get breast cancer?

Unfortunately, that’s not true. Up to 95 percent of women with breast cancer and 85 percent of women with ovarian cancer do not have a mutation in the BRCA genes. The lifetime risk for the general population to develop breast cancer is about 13 percent, and 1.3 percent to develop ovarian cancer. However, there are things you can do to decrease your risk of breast cancer.

Knowledge is power

Breast cancer can be intimidating, but I hope this discussion has eased your mind. Don’t be afraid to ask your doctor any further questions. Understanding BRCA mutations, diagnostic tests and cancer prevention measures will help you and your family stay well and happy.

A native of San Diego, ASPS member Christopher Shale, MD, received his undergraduate degree in Nuclear Engineering at the University of California-Berkely and went on to medical school at Jefferson Medical College. He did General Surgery internship at U.S. Naval Hospital Balboa in San Diego, and after a tour with a Marine helicopter squadron deployed to Iraq, he completed his plastic surgery training at Scott & White Hospital. He’s now a plastic and reconstructive microsurgeon in Utah, specializing in breast and oncologic reconstruction as well as cosmetic surgery.