Angelina Jolie Has Preventative Double Mastectomy

The BRCA1 and related BRCA2 genes belong to a class of human genes known as tumor suppressors. According to the U.S. National Cancer Institute, in normal cells, the BRCA1 and BRCA2 genes help to maintain the stability of a cell's genetic material called DNA -- and help prevent uncontrolled cell growth. Mutation of these genes has been linked to the development of hereditary breast and ovarian cancer.

An estimated 12 percent of women -- or 120 out of 1,000 -- in the general population will develop breast cancer during their lives. But in women with a mutation in BRCA1 or BRCA2 genes, the risk of breast cancer increases dramatically. Approximately 60 percent of women -- 600 out of 1,000 with these genetic mutations -- will be diagnosed with breast cancer. Said another way, a woman who has inherited a harmful BRCA1 or BRCA2 mutation is about five times more likely to develop breast cancer than a woman who doesn't have such a mutation, according to the U.S. National Cancer Institute (NCI).

These genetic mutations are most commonly found in Jewish women of eastern European descent. Also, Norwegian, Dutch, and Icelandic peoples have higher rates of BRCA1 and BRCA2 mutations, according to the cancer institute.

A double mastectomy involves removing as much "at-risk" tissue as possible to reduce the risk of cancer. The procedure does not, however, guarantee complete protection against cancer, according to the NCI.

Writing in the Times, Jolie said, "My doctors estimated that I had an 87 percent risk of breast cancer and a 50 percent risk of ovarian cancer, although the risk is different in the case of each woman.

"Once I knew that this was my reality, I decided to be proactive and to minimize the risk as much as I could. I made a decision to have a preventive double mastectomy."

Jolie said the process of having her breasts removed was finished by late April, and included the reconstruction of both breasts with implants. "There have been many advances in this [reconstruction] procedure in the last few years, and the results can be beautiful," she wrote.

According to the NCI, genetic testing can reveal whether a woman carries a BRCA1 or BRCA2 mutation. There are benefits to such testing, whether a woman receives a positive or a negative result. "The potential benefits of a negative result include a sense of relief and the possibility that special preventive checkups, tests, or surgeries may not be needed. A positive test result can bring relief from uncertainty and allow people to make informed decisions about their future, including taking steps to reduce their cancer risk," the agency said.

For her part, Jolie said: "I wanted to write this to tell other women that the decision to have a mastectomy was not easy. But it is one I am very happy that I made. My chances of developing breast cancer have dropped from 87 percent to under 5 percent. I can tell my children that they don't need to fear they will lose me to breast cancer.