Celebrity | Robin Roberts Joan Lunden: I Have Breast Cancer Former 'GMA' co-host returns to show to reveal diagnosis By Evann Gastaldo Posted Jun 24, 2014 10:11 AM CDT Copied In this Sept. 12, 2008 file photo, Joan Lunden attends the Badgley Mischka 2009 spring collection in Bryant Park during fashion week in New York. (AP Photo/Peter Kramer, file) Joan Lunden returned to Good Morning America today to reveal that she's fighting breast cancer. Lunden, 63, co-hosted the morning show from 1980 to 1997, and she sat down with current co-host Robin Roberts, who's had her own health struggles recently. Lunden said she has "the aggressive kind" of breast cancer, and is already undergoing chemotherapy, but that she's optimistic about her prognosis, People reports. (ABC's Amy Robach was also diagnosed with breast cancer after an on-air GMA mammogram last year.) Read These Next America's most popular cooking oil is tied to weight gain. Kristi Noem issues a warning: 'We don't want them.' A troubled teen in Brazil climbed into a lioness' enclosure. Car buyers appear to be getting fed up with soaring prices. Report an error