Three sisters face breast cancer together

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By TODAY Health and Lisa A. Flam

Brenda O’Brien thought she'd gotten her family's share of bad luck when her breast cancer roared back out of remission. But within a year, both her younger sister, Angel, and her older sister, Kathleen, received the same devastating news: They too had breast cancer.

“As far as statistics go, I thought, ‘OK, I can handle it. I can deal with it, and they won’t have to deal with it,’” Brenda O’Brien told TODAY, gesturing to her siblings. 

“And then it was just shocking to then hear she (Angel) was diagnosed and then Kathy,” O’Brien told TODAY's Amy Robach. “That was very hard.” 

The women have the same breast cancer gene mutation, which increases the risk of developing the disease. And they have a family history of breast cancer. Their mother survived the disease when they were kids, and it claimed the life of their maternal great-grandmother. 

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Only 5 to 10 percent of breast cancers are genetic, and the fact that all three sisters developed the disease at the same time makes their story even more unusual. 

“Because most breast cancers are not hereditary, it’s very uncommon for three sisters to have breast cancer,” Dr. Rebecca Brightman, a clinical instructor of obstetrics and gynecology at Mt. Sinai Hospital, told 

Darlene O'Brien, the three sisters' mother, died of appendix cancer in 2000. She told her daughters: “I finally realized what would be worse than this. If one of you girls had this.” 

The sentiment rings bittersweet for the sisters as they fight their cancers together. The women say their mother, who stayed positive in the face of cancer, is with them today.

“I feel like she’s with me all the time still,” Brenda O’Brien said, “leading us into the right places and helping us.”

On TODAY, the women sought to raise awareness about the deadly disease, with Angel supporting genetic testing and Kathleen touting the benefits of early detection.

“Women all over the world really need to go out and be tested no matter how fearful they are,” said Kathleen, who wears her mother’s wedding ring. “Because early detection does make such a huge difference. And if you’re not getting the right answers where you go, you need to go get a second opinion.”

After lung cancer, breast cancer is the leading cause of cancer deaths among women. The American Cancer Society estimates that 226,870 new cases of breast cancer will be diagnosed this year, and that nearly 40,000 women will die from the disease.

While it’s not uncommon for siblings with a family history of breast cancer to get disease, the O’Brien case -- three diagnoses in a year -- is rare, said Dr. Otis Brawley, the cancer society’s chief medical officer and a breast cancer specialist.

“It’s very unusual for any doctor to have three sisters with breast cancer at one time,” he told

A genetic test can determine if you have a genetic mutation associated with breast cancer. Women who have a breast cancer gene mutation have a 40 to 80 percent chance of developing breast cancer, said Brightman, adding that family history should play a major role in who gets screened.

Brawley encouraged women with a family history of breast cancer to work with a genetic counselor to weigh the risks and benefits of genetic testing.

A test is helpful when it uncovers a known mutation. But there are mutations whose significance is still unknown, he said. Brawley recalled a woman who chose to have both breasts removed based on genetic testing, only to find out four years later that her mutation carried no risk.

As they deal with their disease, the O’Briens have each other and are connecting with the world through their Facebook page. They appeared upbeat on TODAY.

Kathleen had surgery about a month ago, Angel is undergoing radiation and Brenda is in the midst of reconstructive surgery.

“I’m not moving this arm too much but ... feeling good,” Brenda said with a laugh.

“Every day is different,” Angel said. “But just get up and put a smile on your face and do your best.”

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