What does it mean when Angelina Jolie, the Hollywood actress and activist who epitomizes beauty and sexual power, tells the world that she’s just had a double mastectomy? It’s almost as if Marilyn Monroe announced she had her breasts removed.

“I started getting e-mails at 6 a.m.,” said Eleni Tousimis, the chief of breast surgery at MedStar Georgetown University Hospital. “When such a beautiful woman and icon talks about this openly, it just changes everything.”

The op-ed by Jolie in Tuesday’s New York Times about her decision to remove her breasts and therefore reduce her chances of getting breast and ovarian cancers, was in many ways more shocking than a cancer diagnosis itself, especially in a society in which a Hollywood superstar’s appearance — specifically Jolie’s breasts — is seen as a public commodity. But, this is a fact that Jolie’s now proudly dismissing as defining her or her value.

“On a personal note, I do not feel any less of a woman,” she wrote. “I feel empowered that I made a strong choice that in no way diminishes my femininity.”

Jolie, 37, is already well-known for her unconventional behavior. She had a very public and dramatic journey — from a dark, wild spirit who once wore a vial of then-husband Billy Bob Thornton’s blood around her neck when she won an Academy Award for playing a sociopathic mental patient in 1999’s “Girl, Interrupted” to her current do-gooder life as a mother of six and global humanitarian. She spends lots of her time visiting places such as Congo and Darfur, and speaking out against sexual violence.

Cancer survivors and others around the world took to social media to praise her decision “as brave and honest.” Breast cancer survivors often joke that their reconstructed breasts are firmer and look better in clothes. Jolie could have easily avoided saying anything and her new breasts probably would have gone unnoticed. Or as the actress said, “The results can be beautiful.”

“She’s a superwoman and more sexy already, if that’s even possible,” said cartoonist Marisa Acocella Marchetto, a breast cancer survivor and author of the graphic novel “Cancer Vixen.” “ . . . It’s that fearlessness that makes her attractive. She’s the most awesome woman in the world and just got even more awesome, in my book.”

But skeptical voices ask if a celebrity, empowered by fame and wealth, could cause a rush of expensive testing, leading to panic and misinformation.

Well-known personalities who have spoken about the importance of getting tested and treated for prostate cancer, for example, “have done harm because the information they put forth is actually misinformation,” said Otis Brawley, chief medical officer for the American Cancer Society.

Among prostate cancer survivors, about half of those treated “would not have been bothered by the disease” if they not had been diagnosed in the first place, Brawley said.

Jolie shared that once she knew she carried a harmful mutation of the BRCA1 gene that gave her an 87 percent chance of developing breast cancer and a 50 percent risk of ovarian cancer, having surgery and reconstruction made it easier for her to reassure her children and her partner, Brad Pitt, that she would stave off cancer. Her mother died of ovarian cancer at 56.

Pitt, Jolie wrote, supported her and told London’s Evening Standard on Tuesday that her decision was “absolutely heroic.”

“I found in my research for my book that most husbands do support their wives and tell them they will love them just as much,” said Marc Silver, author of “Breast Cancer Husband: How to Help Your Wife (and Yourself) during Diagnosis, Treatment, and Beyond.” “But that doesn’t mean it’s some easy decision.”

Jolie’s disclosure has opened up discussion on the wisdom of celebrities as role models in medical decisions. Hours after Jolie revealed that she had a preventive double mastectomy, the American Cancer Society issued a lengthy statement Tuesday urging caution.

The condition that Jolie has is a rare harmful mutation in a gene called BRCA1. Less than 1 percent of all women have a mutation in that gene or another one called BRCA2, Brawley said.

Mutations in the two genes are estimated to account for 5 to 10 percent of breast cancers and 10 to 15 percent of ovarian cancers among white women, according to the National Cancer Institute.

Men with these mutations also have an increased risk of breast cancer. About one-third of all men who have breast cancer have these mutations, Brawley said.

Brawley praised Jolie for showing “tremendous understanding of this disease and the problem of genetic mutation.” Her op-ed was reasonable and science-based, he said.

But some cancer experts are worried that women and their families might hear only part of Jolie’s message “and rush out and get an expensive test,” he said.

The rush to test could be particularly worrisome because the analysis screening has become significantly less expensive under the new health law, the Affordable Care Act. The genetic test is among the preventive services that insurers are required to cover without cost to the patient.

The U.S. Preventive Services Task Force recommends that only women with a strong family history of cancer be evaluated for genetic testing for BRCA mutations. This group represents only about 2 percent of adult women in the United States, experts said.

The task force recommended against widespread BRCA screening in 2005 and reiterated that stance in draft recommendations last month.

Brawley likened the BRCA1 gene to a word that is 200,000 letters long, with a mutation being any misspelling. Some mutations, like the one Jolie has, are linked to very high risks for breast cancer. Others are associated with a lesser cancer risk, still others are linked to risks of undetermined significance and a few mutations appear to be linked to no significant increased risk of breast cancer, he said.

“When I have a woman who has no family history and a mutation of undetermined significance, I don’t know what that means,” Brawley said. “I know that woman is going to freak out and want to get treated, but I don’t know that she needs that.”

By comparison, if a woman had the same mutation of undetermined significance but had a family history of breast cancer, that risk “is likely to be significant,” he said.

Surgery to remove both breasts before cancer is diagnosed can greatly reduce the risk of breast cancer, by as much as 97 percent, but it does not prevent breast cancer because even a very careful surgeon could leave behind a small amount of breast tissue that might become cancerous, according to the statement issued Tuesday by the American Cancer Society.

But Jolie’s op-ed probably will inspire other women to find out more information and think about their choices, said Tousimis, of Georgetown hospital.

“There are many options when you test positive and sometimes that’s very close monitoring,” she said. “But what I like about this is the title of her essay, ‘My Medical Choice.’ She had the gene test and made an informed decision and shared it. It’s a powerful moment.”