Angelina Jolie's surgery: What you need to know about double mastectomy

United Nations High Commissioner for Refugees (UNHCR) special envoy Angelina Jolie speaks during a press conference at the government palace in Beirut, Lebanon, Sept. 12, 2012.
AP Photo/Hussein Malla

(CBS News) Angelina Jolie says she revealed her story about her double mastectomy surgery in order to help other women at risk for cancer.

Jolie, 37, wrote in an op-ed in the New York Times that she underwent the surgery in an effort to reduce her risk of cancer because she possesses a so-called "faulty" version of the BRCA-1 gene, which predisposes her to cancer.

Angelina Jolie: I had preventive double mastectomy

BRCA1, an inherited gene that can pass on to a son or daughter, dramatically raises the risk for breast cancer and ovarian cancer, CBS News medical contributor Dr. David Agus explained Tuesday on "CBS This Morning."

There are two forms of the gene. There's BRCA1 and BRCA2. In normal cells, they are actually called tumor suppressor genes and they help to prevent the development of cancer, CBS News' Dr. Holly Phillips explained. "In people who have the mutation, it actually raises the risk of developing both breast cancer and ovarian cancer," she said. "In Angelina Jolie's case, she said the doctors estimated her lifetime risk of getting breast cancer around 87 percent."

Some people, such as those of Ashkenazi Jewish or Scandinavian descent are at a higher risk for the "faulty" gene. However, some people don't know their family history, and, Phillips added, "If you've had a male relative or one or two close female relatives with breast cancer, (testing is) something you want to consider."

There are no national standards for testing, but if you are someone who has a first-degree relative or two first-degree relatives at a young age with breast cancer, you need to be tested, Agus, director of the Westside Cancer Center at the University of Southern California, said.

For more with Agus, watch his full interview in the video below.

"The big issue came in the Supreme Court last month where they started to argue that a company is charging $3,000 for the test -- is it appropriate," Agus said. "A woman needs to know her own genetics and know her risk. The problem is much insurance doesn't cover the people who are moderate or lower risk and many people don't have insurance and they can't be tested and prevent this horrible disease."

About 5 percent to 10 percent of people with breast cancer have a mutation in the gene BRCA1 or BRCA2, Agus added.

In terms of the double mastectomy, Agus said "there is no right answer here."

He added, "Having a double mastectomy, the real benefit is that you dramatically reduce your risk of breast cancer. It doesn't go to zero because there is some breast tissue left, but it goes from in the case of Ms. Jolie the 80 percent range down to about 5 percent. The risk is that it is major surgery. Many people don't want that. So there are pills that one can take that can again dramatically reduce risk but it is taking a pill every day for the rest of your life and we don't have a lot of real long-term data with these pills yet."

Jolie has said her next step may be having her ovaries removed, CBS News' Norah O'Donnell added.

Agus remarked, "(Jolie) has about a 50 percent chance of having ovarian cancer. That's a dramatically increased risk from the average woman. Taking out ovaries is a relatively simple surgery, but is a big decision for a woman to make."

Watch Phillips' full "CTM" appearance in the video below.

Speaking of Jolie's decision, Phillips said, "I really commend Angelina Jolie. She's obviously somebody who talks the talk, but then walks the walk. You know, she really I think is making a difference just in terms of awareness of breast telling everyone what she went through. Those are very high numbers -- an 87 percent lifetime risk. She's made the decision to be pro-active and do a double mastectomy rather than reactive and treat breast cancer."