Miss America contestant explains double mastectomy

• Washington representative is opting for preventive surgery
• Her mother and grandmother died of breast cancer

Her name is Allyn Rose. She's 24. A Miss America contestant.

And Rose, a Maryland native who is representing Washington, D.C., is going to have a double mastectomy after the January pageant.

Many of the women in her family have died of breast cancer, she says, so she's opting for the surgery as a preventive measure. Her mom, she said, was diagnosed at age 27, and died when Rose was 16. Her grandmother also died of breast cancer.

This morning on Good Morning America, Rose explained, "It's incredibly drastic, but at the same time it's something that can help prolong my life."

She added, "I'd rather do something that helps me be here for my children, that helps me be able to live a long and healthy life."

She has had doctors tell her that it's something she could wait to do later, but she cites her mom. "It's not a risk I'm willing to take."

When her dad told her, "I don't want you to end up dead like your mother," that made her take the "proactive" route.

As for the beauty pageant world, she says, "This probably will be my last pageant."

GMA's Robin Roberts, who is a breast cancer survivor, tweeted support for Rose while she was on the air: "Proud of Miss DC @AllynRose, being proactive in fighting breast cancer. Admire your courage & candor sharing your decision w/ us. Blessings"

The Miss America Pageant airs live on ABC on Jan. 12. Rose told People magazine that if she's crowned the winner, she'll wait to have the procedure and reconstructive surgery once her year-long reign is up in January 2014. Should she lose, she'll have the surgery in June.