Joan Lunden, former 'Good Morning America' host, reveals she has breast cancer

Former "Good Morning America" host Joan Lunden says she has breast cancer.

She disclosed her diagnosis on Tuesday's edition of the ABC morning show, which she co-anchored from 1980 through 1997. She spoke with "GMA" host Robin Roberts, who has also been treated for breast cancer recently, as has "GMA" co-host Amy Robach.

Lunden said her treatment will include surgery and radiation. She said she's already started chemotherapy.

She said after the initial shock of the diagnosis, she resolved to learn everything she can about the illness and go into what she called "warrior mode." She said she expects to make a full recovery.

The show's news anchor Robach recently spoke out about her struggles with chemotherapy, telling the New York Daily News suffered memory loss from the treatment.

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She was unable to recall filming an entire segment for "Good Morning America" and was shocked to see it on-air.

“It brought tears to my eyes because I just could not believe that I couldn’t remember doing any of it. I figured that out when I was in the moment, doing things, I functioned — but I couldn’t remember doing any of it afterward," she said.

Robach was diagnosed with cancer after she got a live on-air mammogram for a segment on the show. She completed her chemo treatments in April.

The Associated Press contributed to this report.