Preventive mastectomy: understanding Angelina Jolie's decision

Actress Angelina Jolie’s revelation that she has undergone a preventive mastectomy to reduce her risk of breast cancer is all over the news, drawing attention to mutations in genes BRCA 1 and BRCA 2 that dramatically elevate some women’s risk for the disease.

Writer Jenny Hall spoke to Kelly Metcalfe, a professor at the Lawrence S. Bloomberg Faculty of Nursing at the U of T and an adjunct scientist at the Familial Breast Cancer Research Institute at the Women’s College Research Institute.

Metcalfe researches the prevention and treatment of cancer in those with an increased risk of developing the disease. She has published extensively on the treatment of BRCA-associated breast cancer, and the implications of cancer preventive options including mastectomy.

What was your reaction to the news that Angelina Jolie underwent a preventive mastectomy?
It’s not surprising. We know that women are making this decision every day. Now we know there’s a celebrity who is making that decision. I’m sure there are more celebrities we just don’t know about. But genetic testing is common. It is a part of medical care now. If a woman meets criteria in any of the provinces—they’re based on family history of cancer, the types of cancer, the age of onset—she’s eligible to be tested at no cost.

Can you tell me about this genetic mutation that Jolie has?
We all have genes called BRCA 1 and 2. It’s only when there’s a mutation or a mistake that can be passed down from a parent to a child, that you have a problem. When there’s a mutation, your body can’t fight cancer off very well. That’s why we see higher rates of cancer in these individuals and we see earlier ages of onset. Breast cancers that result from these gene mutations typically happen in the 30s and the 40s. And women with mutations are also at a very high lifetime risk of developing ovarian cancer.

Because these genes are involved in fighting both breast and ovarian cancer?
That’s right.

How common are these mutations?
It’s about 1 in 250 to 1 in 400 in Caucasian women. It’s much more frequent in certain groups—like Ashkenazi Jews, where it’s about 1 in 50.

What proportion of women with breast cancer developed it because of these mutations?
Five to 10 per cent of all breast cancers are due to these mutations.

Of women who have a mutation, how many go on to have a mastectomy?
About 30 per cent of Canadian women who are identified as having a mutation will elect to have a preventive mastectomy.

What do the rest do?
There are other preventive procedures, though none of them reduce the risk as much as preventive mastectomy. Women can take a drug called Tamoxifen, but we know that very few women—less than 10 per cent—elect to do this. You can also have your ovaries removed. We strongly encourage women to have their ovaries removed because we don’t have good screening for ovarian cancer. The great majority—80 per cent—have their ovaries removed. That also offers protection against breast cancer if they do it young enough, before the age of 50.

All women with a mutation are involved in very intensive cancer screening programs. They all have annual breast MRIs in addition to mammograms and clinical breast exams.

This must be a difficult, emotional decision for women.
For most women this is the hardest decision. On the other hand, there are women who know exactly what they want to do—they know as soon as they get the results that they’re going for a preventive mastectomy. But for the majority, it is a difficult decision to make. That’s why we encourage women to visit surgeons and talk to them about the options, and to visit other women who have undergone this type of surgery. We want a woman to have a realistic expectation of what she might expect to look and feel like after surgery.

Do some women have the mastectomy and not do breast reconstruction?
In cases of bilateral prophylactic mastectomy (without a diagnosis of breast cancer), almost all women elect for breast reconstruction done in the same surgery as the bilateral mastectomy. With no cancer there, they can conserve the skin and the nipple. They just go in and scoop the breast tissue out and reconstruct at the same time. A woman is never going to look exactly like she did before, but we have some great plastic surgeons, especially here in Toronto, and they’re really able to work with the woman so she can decide what she wants to look like after the surgery.

You’re involved in helping women with these mutations. What do you do?
I work at Women’s College Hospital. I see women after they’ve received their genetic test results and have met with the genetic counsellor. If they’re having difficulties making decisions, I spend time with them, explaining their options and going over some of the pros and cons and helping them work towards a decision.

And what about your research?
My research is in cancer prevention. I’m following huge populations of women who have these genetic mutations. I publish on the rates of uptake of the various decisions.

Overall, do you think Jolie’s revelation is going to have a positive impact?
It’s going to draw attention to the fact that this is out there, that it’s available. I hope it doesn’t instil fear in women. We have to remember that these genetic mutations are rare. It’s important to know your family history, and not just for cancer, for everything. With breast cancer, we’re fortunate to be able to look at our family histories and we have genetic testing to determine if we really are at the high risk suggested by those histories.

Jenny Hall is a writer with the Office of the Vice-President, Research and Innovation