Angelina Jolie doesn't have cancer - here's why she had her ovaries and breasts removed

Tuesday morning actress and sex symbol Angelina Jolie announced that she had both of her ovaries removed in a preventative surgery to reduce her risk for ovarian cancer after some signals of precancer turned up on a routine scan.

She had a previous surgery in 2013 to remove her breasts because she has a mutation in a gene called BRCA1 which increases the risk of breast and ovarian cancers.

"I did not do this solely because I carry the BRCA1 gene mutation," Jolie clarified, in her New York Times essay about removing her ovaries. But that was a major part of her decision.

What's the risk?

Mutations in the BRCA genes (there are two, named 1 and 2 respectively) increase a person's risk for cancers, including breast and ovarian. Only about 0.25% of the general population has mutations in one of these genes.

While this is only a small amount of the population, someone who carries a mutation in one of these genes is much more likely than the average person to get cancer. A New England Journal of Medicine study indicates that having a mutated BRCA gene increases your lifetime risk of breast cancer to between 60% and 85%, and a lifetime risk of ovarian cancer between 15% and 40%, depending on the gene and the mutation.

The mutation is present in about 2% of female breast cancer cases and 10 to 15% of ovarian cancer cases.

Men with BRCA mutations are also at an increased risk for cancer, including male breast, pancreatic, and prostate cancers.

One dangerous mutation

Genes are the blueprint for the proteins that make up every cell of our body. They are made of a code of DNA letters, which sometimes are copied wrong when cells multiply, creating a mutation in the gene. When a gene is mutated, it could stop working correctly, which may result in health problems.

In the case of the BRCA mutations, the normal BRCA genes act as "tumor suppressors" - genes that protect cells from growing out of control and becoming cancerous. Unmutated BRCA genes help repair mistakes in genes that are commonly made when a cell multiplies and play a role in the "cell cycle" which regulates how quickly cells grow and multiply.

Therefore, a non-functioning BRCA gene could let tumors develop and also fail to prevent other cancer-promoting mutations.

Any given cell usually needs more than one mutated tumor-suppressor gene to become cancerous, however, which is why having one mutated BRCA gene isn't necessarily a death sentence.

Different mutations

Another important note on mutations in the BRCA genes - they aren't all the same. Mutations in different parts of the gene have different effects. Not all mutations break the gene completely - and there is no definitive test to tell if you have a BRCA gene that is fully broken or still works just fine even with a mutation.

In 10 to 15% of cases where doctors see a mutation in the gene they can't say whether it will break the gene and contribute to cancer risk.

In Jolie's case, however, her doctor reportedly said that her mutation carried a 87% risk of breast cancer and a 50% risk of ovarian cancer. She has previously lost her mother, grandmother and aunt to cancer.

A lifetime of risk

Since discovering her risk, Jolie had her breasts removed to prevent breast cancer, and now, after showing pre-cancerous signals on a test, has had her ovaries and Fallopian tubes removed. As Jolie wrote for the New York Times:

Then two weeks ago I got a call from my doctor with blood-test results. "Your CA-125 is normal," he said. I breathed a sigh of relief. That test measures the amount of the protein CA-125 in the blood, and is used to monitor ovarian cancer. I have it every year because of my family history.But that wasn't all. He went on. "There are a number of inflammatory markers that are elevated, and taken together they could be a sign of early cancer." I took a pause. "CA-125 has a 50 to 75 percent chance of missing ovarian cancer at early stages," he said. He wanted me to see the surgeon immediately to check my ovaries.

After ultrasounds, a fully body scan, and blood tests put her in the clear for cancer, Jolie decided to stop waiting to have the ovary removal surgery. It is a difficult choice for many women; the surgery will put Jolie into early, forced menopause and she won't be able to have more children naturally.

She doesn't think that every woman should jump to this drastic surgical intervention, though:

I did not do this solely because I carry the BRCA1 gene mutation, and I want other women to hear this. A positive BRCA test does not mean a leap to surgery. I have spoken to many doctors, surgeons and naturopaths. There are other options. Some women take birth control pills or rely on alternative medicines combined with frequent checks. There is more than one way to deal with any health issue. The most important thing is to learn about the options and choose what is right for you personally.But for Jolie the choice was simple: "I feel feminine, and grounded in the choices I am making for myself and my family. I know my children will never have to say, 'Mom died of ovarian cancer.'"

Note: We relied heavily on the National Cancer Institute's wonderful, but very technical, summary of the Genetics of Breast and Ovarian Cancer for this post.

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