Double Mastectomy: Why Angelina Jolie Had Breast Removal Surgery

Actress Angelina Jolie has undergone a preventive double mastectomy, she revealed Tuesday in The New York Times.

She wrote an opinion piece, titled "My Medical Choice," explaining that she underwent the breast removal procedure because she has a mutated BRCA1 gene known to raise a woman's risk of breast and ovarian cancers.

The BRCA1 and BRCA2 genes work in the body to keep DNA stable and to make sure cells don't grow out of control, according to the National Cancer Institute. But certainmutations of these genes can dramatically raise cancer risk.

Jolie, 37, explained her risks from BRCA1 in the piece:

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.

Only a fraction of breast cancers result from an inherited gene mutation. Those with a defect in BRCA1 have a 65 percent risk of getting it, on average.

Jolie began the process on Feb. 2, when she underwent a "nipple delay" procedure to make sure there is no breast cancer behind the nipple. She completed all the mastectomy procedures on April 27, including breast reconstruction with an implant, she wrote.

"I wanted to write this to tell other women that the decision to have a mastectomy was not easy," she wrote. "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."

The type of mastectomy a person undergoes depends on each individual case. Nipple-sparing mastectomy only involves surgical removal of breast tissue -- not the nipple or areola -- while skin-sparing mastectomy involves removal of all the breast except for the breast skin, according to the Mayo Clinic. A simple mastectomy involves surgical removal of the whole breast, while a modified radical mastectomy involves surgical removal of the whole breast in addition to the chest muscle lining, underarm lymph nodes and sometimes a part of the chest wall.

CNN recently reported on a study showing that preventive mastectomy, also known as prophylactic mastectomy, is more common in the United States than in other countries.

However, the same study showed that many American women get the procedure toprevent cancer recurrence, even though it may not be necessary because of their breast cancer types, AnnArbor.com reported. The procedure is recommended for people like Jolie -- those with a known genetic risk because they possess the BRCA1 or BRCA2, or have a strong family history of the disease, NPR reported.

Earlier this year, 24-year-old Miss America contestantAllyn Rose, announced she was undergoing a preventive mastectomy because she has a strong family history of breast cancer (her mother has the disease).