9 Q&A: What you should know about the role of genetics in breast cancer

CINCINNATI - October is National Breast Cancer Awareness Month. Women with a family history of breast cancer share a common worry: Will I get it, too? WCPO talked about the role of genetics in breast cancer with Dr. Hilary Shapiro-Wright, a breast surgeon with Mercy Health Physicians.

1. How much of a genetic link is there for breast cancer?

Overall, about 10 percent of breast cancers occur in women who are genetically predisposed. It’s not that they have a familial history, but that they have a gene that would predispose them.

2. What percentage of people who have breast cancer have a family history of the disease?

It depends on what you’re including as family history. Is it first-degree relatives? (Mother, daughter or sister). We split cases into sporadic and those with a gene mutation. Eighty-five to 90 percent of breast cancers are what we consider sporadic. But it’s not a genetic or hereditary predisposition. It’s hard to just say family history. Because almost anybody has a family history of breast cancer if you include second cousins, aunts or grandmothers.

3. How close does the family member have to be for that link to be a concern?

If I’m looking at a new breast cancer patient, the things that would raise a red flag that would make me think there a possibility of a gene mutation or a strong risk are: Women diagnosed younger than 45, or depending on family history maybe 45 to 50; women with another first-degree relative  that has the gene (that’s a mother, daughter or sister); women who have multiple first-degree family members who may have been tested, are negative, but they’re young. I still would test the patient. If your mother had breast cancer, and your sister had breast cancer, and your sister was tested and came back negative, I would test you. Your mother may have had the gene. And you have a 50 percent likelihood of passing it.

4. What are the reasons someone should consider genetic testing to look for the gene mutation that’s linked to breast cancer?

Women who are younger than 45 with multiple first-degree family members. Men with breast cancer. Women who have men in their family with breast cancer. Women of Ashkenazi Jewish decent. Also, women who are diagnosed with either bilateral breast cancer at the time of their diagnosis or have been diagnosed two separate times with two separate cancers. And women with a family history of ovarian cancer.

5. Are there people for whom regular mammograms are more important because of a family history?

No. A screening mammogram is important for all women. The recommendation is to begin at age 40 for women of average risk. For women with first-degree family members who have had breast cancer, the recommendation is 40 or 10 years prior to the age of diagnosis of the first-degree relative, whichever comes first. If your mom was diagnosed at 45, you would begin at 35.

For women with the gene mutation, they would screen with mammograms and annual MRIs. They follow the high-risk model. They are seen every six months for a clinical breast exam by a breast specialist. They get an annual screening mammogram and an annual screening MRI completed 6 months apart. And there are risk-reducing medications we can offer.

6. Is the genetic link true for men and women?

It’s the same genetic mutation. You would inherit the gene mutation from a parent. It can be either your mother or father. It’s the same gene that would be passed from a mother or a father. One percent of all breast cancers occur in men.

7. Once find out you carry the genetic mutation, what are the implications?

Women who have the breast cancer gene have a 90 percent chance  of getting it. For ovarian cancer, there’s a 60 to 70 percent risk. The gene also can be linked to testicular and pancreatic cancer.

From that standpoint, the patients are considered high-risk. For women, if they choose to do prophylactic mastectomy, that’s a choice. They can continue to be screened regularly.

Reconstruction can be completed with prophylactic mastectomies. And we do recommend they have their tubes and ovaries removed as well. If the woman chooses to keep her breasts, we recommend a risk-reduction medication.

8. For women who test positive for the gene, if they have children, do you recommend they have their children tested?

There is a 50 percent likelihood of passing the gene because half a child’s genetic material comes from the mother, and half comes from the father. If a woman is tested and be found to be positive, you can test her children. However, there’s only a 50 percent chance she would pass that gene to her children.

Next page: What do you recommend?

9. What do you recommend?

It’s a personal choice. There are laws that prevent insurance companies from holding back insurance if a genetic risk factor is identified. It’s a personal choice. It’s not something I would tell a patient to do or not to do. I let them make an educated decision.

My goal is not to tell a patient this is what you have to do. I believe my job is to educate the patient so they can make an educated decision. Some people want to know, and they believe knowledge is power. Other people don’t want to know. And that’s a personal decision.

Doing the genetic testing is great. The counseling that comes with the testing is just as important as the testing. Meeting with a certified genetic counselor is part of the process here at Mercy Health.

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