Former "Good Morning America" host Joan Lunden made a bittersweet return today to the show that helped make her a household name; announcing that she was recently diagnosed with breast cancer

The 63-year-old, co-host of "GMA" from 1980 to 1997, revealed her battle to Robin Roberts - who along with “GMA” news anchor Amy Robach, has also been treated for breast cancer

"I heard those words that every woman fears and never wants to hear, 'You have breast cancer,'" she told Roberts. "In the beginning, it's such a shock. It's a stunner… For me, I'm a health advocate, I'm all over America talking to women, saying, 'Make sure that you get all of your checkups all the time.' You almost feel like, 'What did I do wrong?'"

In a blog post published during her interview on television, Lunden says doctors discovered a tumor in her right breast after a routine ultrasound. 

"I considered myself fit and healthy, I get checked faithfully every year and I didn’t have a history of breast cancer in my family," she writes. "But of course after covering many stories about breast cancer over the years, I knew that none of us are exempt. I also knew that I had to jump into action quickly, put together a team, and find the best course of treatment for the kind of cancer that I have."

According to her publicist Stan Rosenfield, Lunden's next steps will include a lumpectomy, chemotherapy and radiation.  

"I have decided to talk about my breast cancer because since the moment I took the job at Good Morning America I have lived my life sharing my joys and my disappointments with all of you: my pregnancies, my relationships, my career… I have shared my journey. So it certainly didn’t feel right keeping this part of my journey a secret." 

Lunden also credited her late father with giving her the inspiration to share this very private battle with the public. 

"My father was a cancer surgeon and he died when I was a young girl on a flight home from speaking at a Cancer Conference," she writes. "I so admired my father’s passion to save lives and work toward a cure for cancer. I thought about what he would say if he knew that I was going through this and that I had ultimately lived my life in front of an audience. I knew that he would want me to use this experience as an opportunity to spread the word about how important it is to get screened for all types of cancers and for women to do self-breast exams.

"Early detection is so crucial, I consider myself fortunate that I found this in the early stages and the prognosis is so promising."

According to her doctors, Lunden is expected to make a full recovery. You can view her interview with Robin Roberts on "Good Morning America" below. 

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Joan Lunden reveals breast cancer fight
Former 'Good Morning America' host says she's fortunate to have discovered the cancer in its early stages.