Transcript for Miss America Contestant to Undergo Double Mastectomy
She does look fantastic. Another fantastic woman, allyn rose. The 24-year-old is announcing she will underknow major surgery, a double mastectomy just after the pageant. This after losing her mother to breast cancer. She's removing her breast as a precaution. Almost all the women in her family, in fact, have died of breast cancer. Allyn joins us. Thank you for joining us. Thank you. What made you decide to have both breasts removed than take the chance of contracting it? Well, my mother was diagnosed at the age of 27. SHE PASSED AWAY IN HER 50s. And I heard what it was like, from her, to lay in the hospital bed after losing her breast to say I may never run again. She was a marathon runner. I may never finish my degree, what man is going to love me with one breast. At that moment, she said I'm not going to give up and cancer is not going to win. She didn't let cancer define her life. And she lived a wonderful life and she was the most beautiful and resilient woman. I thought if my mother can do this, I can do this. I want to be around for my children. How long have you known that you had this genetic predisposition? What age did you learn that? They did that testing when i was a child so I knew I had it for a while. When I passed 16, it was one of those things I thought I can be incredibly vigilant for the rest of my life or doing some drastic that can prolong my life. Anything I can do, absolute, I'm going to go with that. What do doctors tell you the chances are if you don't have the mastectomy what the odds are? Don't know what the odds are. But to have your mother DIAGNOSED IN HER 20s AND THEN Come back at a later age. My grandmother died of breast cancer. Her sister died of breast cancer. There's such a large predisposition to breast cancer in my life. I'd rather be here for my children and be able to live a long healthy life. Doctors are not in agreement with your decision. You've had doctors tell you that they don't think you should do this? It's not necessarily that they don't think I should do this. Maybe it's something that i could wait to do later in life. But, I mean, my mom almost died at 27. And to be 24 and to know that that's three years away from me, to know that I could be facing a battle for my life, you know, it's not a risk that I'm willing to take. And in fact, your dad and your mom met after her first battle with breast cancer. Tried to convince her second breast removed as well, and she didn't. And that was the breast where she contracted the cancer that eventually killed her? Yeah. My whole life, my dad said, judy, why not have the surgery, get the second one removed. It could come back. I think it was something where maybe she was worried about losing her other part of her femininity. She was living her entire life with one breast. And to take that extra leap i think was extra scary for her. But it's ultimately what killed her but I'm just, like I say, not willing to take that risk at all. You're going to compete in the miss america pageant. You make a living in the beauty industry, as we say. What is this like going forward after having a double mastectomy, can you continue to compete in pageants? This probably will be my last pageant. It's an incredibly scary decision. I was there with the late bloomers. I had just gotten my breasts and my dad he looked at me, he said I don't want you to end up like your mother. It was oftenen is abrasive incorporate that he said, that it made me take notice. I thought, I neat to be proactive. This is about igniting women's health care and teaching them to be proactive. Allyn rose, thank you for that. Robin saying proud of miss allyn rose being proactive in fighting breast cancer. From one breast cancer survivor to another. Thank you. Thanks for being here. Thank you for having me. You can see allyn rose and allyn compete in the miss america pageant. It will be live here on january 12th right here on abc. Good luck to you. Lara? I'll be cheering for her.
This transcript has been automatically generated and may not be 100% accurate.