TODAY | November 19, 2013
>> men's health to a touching story tied to women's health. twin sisters both diagnosed with breast cancer both helping each other heal in a remarkable way. here's kristen welker.
>> reporter: in 34 years kelly and kristen shared just about everything. identical twins with a special connection that started before they were born.
>> they only heard one heart beat and they think we were laying on top of one another and our hearts were beating as one.
>> reporter: and both their hearts were broken, their families devastated when kelly was diagnosed with an aggressive form of breast cancer two years ago. she was pregnant with her first child.
>> you're thinking at 60, 65 you'll get your cancer diagnosis and something like that. not at 32 and definitely not when you're pregnant.
>> top three worst days of my life. i don't think that i stopped sobbing for weeks it seemed like.
>> i remember you just saying -- the only thing you said --
>> i can't live without her.
>> reporter: kelly , a nurse, started treatment just weeks after her son grey was born. but she had a nagging concern about her sister kristen . not only do they share a set of genes but they lost their mom last year to colon cancer .
>> the nurse and me kept saying kristen get tested, get tested.
>> reporter: she took her sister's advice and the news was stunning. she too was diagnosed with breast cancer .
>> you may have saved your sister's life.
>> she did. absolutely. hands down. she did save my life.
>> both are cancer free. both are recovering well. and very sort of elated at the situation.
>> and last week, kelly and kristen became the fourth twins ever to undergo shared reconstructive breast surgery with kristen donating her belly tissue to help rebuild a breast. this video shows them transporting the tissue.
>> that's the ideal situation where you don't have to use antirejection medication because you have a part of you living with your identical twin .
>> reporter: a fight for life that's brought these twins, both young moms now even closer .
>> she did it to heal me on the outside obviously, but it's healed me so much internally as well. it's amazing to have a part of her on me.
>> reporter: two sisters who truly do make each other whole.
>> we call it twin healing. twin healing. we've always said that.
>> reporter: kristen welker, nbc news, crown point, indiana.
>> and they're with us now. ladies, good morning to you.
>> good morning.
>> it's so good to see you looking so good. i see a couple of tears in those eyes this morning.
>> just a little bit.
>> kelly , how are you feeling? the surgery was a week ago and as we just heard it wasn't an easy one.
>> no it wasn't easy but i'm doing well now. kristen came over for the first time yesterday so i was feeling amazing yesterday.
>> well, kristen when a loved one goes through something often we feel so helpless and here's a situation where you could really help your sister. what did that mean to you?
>> it was amazing just to be able to help rebuild her self-esteem and to put her back to normal or a new normal as we call it now, it was a great feeling.
>> this is a case where you helped each other in so many ways but kelly you're the one at a talked kristen , as i understand it, into going to see the doctor which lead to her breast cancer diagnosis. how did you convince her to go when she didn't want to?
>> well i was going to use the twin card and i said if she didn't go get tested i was going to call and make the appointment under her name for her.
>> well, it worked. kristen , this is so serious. we love seeing you with your smiles and you're both doing so well but you have been through so much recently and your mom passed away from colon cancer and that's one of the reasons why you felt so strongly about moving forward and getting checked out.
>> yeah, being proactive about your health is something you have to be able to do, even at a young age, it's extremely important.
>> kelly i read something you said that was so lovely. you said now your sister is a part of you. she's right part of your heart.
>> yeah, the tissue that they transplanted sits right over my heart.
>> well, it's just a lovely story and kristen , i guess, what's your message to everybody? what do you want people to take away from this story?
>> just to be proactive about their health. to be able to trust their instincts and to trust themselves to know that if you're feeling like something isn't right with your body to take initiative to have it looked at for sure.
>> well, you two are lovely in every way and so profoundly lucky to have each other. thanks for being here and sharing your story.
>> thank you so much.