NEW BEDFORD, Mass. — Dulce Noonan’s cancer diagnosis may have saved her sister’s life.

When Noonan was told she had Stage 3A breast cancer, the news, naturally, frightened her. But the experience was also eerily familiar: Every woman on her father’s side of the family had been diagnosed with cancer.

This family history prompted her doctors to recommend genetic testing for her two sisters. One sister’s results showed no concerns.

But for her other sister, Susane Nunes of Fairhaven, the tests showed she had, like Noonan, genetic mutations to the BRCA2 gene. That significantly increased her chances of having breast and ovarian cancer.

For Nunes, the news resembled a “time bomb” ticking away in the background as she spent her days with her husband and son.

“I didn’t want to go through life saying ‘I might have cancer someday,” she said.

After serious thought and in consultation with medical professionals and her family, Nunes decided to have both breasts and her ovaries removed prophylactically to lower her chances of a future cancer diagnosis.

Noonan had similar surgery. She had both breasts removed, one that had cancer and the other prophylactically. She also had her ovaries and 17 lymph nodes removed.

Actress Angelina Jolie raised the profile of prophylactic surgeries for women with high cancer risks. She recently announced she had her ovaries and Fallopian tubes removed because of her family history and the results of genetic and medical testing.

She previously had her breasts removed in a preventative double mastectomy because of the results of genetic testing.

Making this announcement was courageous, said Dr. Therese Mulvey, physician-in-chief at the Southcoast Centers for Cancer Care, who specializes in genetic mutations.

“She’ll save women’s lives,” she said of Jolie, by encouraging conversations between patients and doctors.

She urged patients to find out as much as they can about family health history. “Your personal history and your genetic history have implications for your entire family,” she said. “People who know that information can make a much more informed decision.”

That decision, she stressed, rarely requires prophylactic surgery. “You need to have an incredibly strong family history” for surgery to be an option, she said. Surgery is the choice in a “very small minority” of her patients.

There are other options for many patients, including more aggressive screening and, in some cases, medication.

Dr. Uma Hari, an OB-GYN with Southcoast Physicians Group, agrees.

“The more knowledge you gain, the better decision you can make,” she said.

Noonan and Nunes stressed that, as Jolie wrote, every woman must make the decision that makes sense for her.