When Good Morning America correspondent Amy Robach agreed to undergo a mammogram on-air last month as part of the show's promotion of Breast Cancer Awareness Month, she did it for the benefit of viewers with little thought to her own health. But as it turns out, the procedure may just have saved her life.

Robach announced today that her October 1 mammogram showed evidence of early-stage breast cancer. On November 14th she will have a double mastectomy and reconstruction, and she'll be taking a leave of absence from the show. She revealed her diagnosis from the GMA couch while sitting next to Robin Roberts, who in 2007 also took time off from the show for breast cancer treatment.

On-air screenings have started to become a clever way for television shows to promote cancer awareness while showing that those avoiding the procedure have nothing to fear. In fact, GMA's morning rival did a similar promotion this month when Al Roker and Matt Lauer had prostate cancer exams on Today, thirteen years after Katie Couric aired her notable colonoscopy on the same program.

So when Robach's producer asked her to do the first on-air mammogram, she agreed because she thought it would encourage other women to get the procedure, not because she was concerned about her own health. "I'm 40 years old. I've never had a mammogram," she said of her reasons for agreeing to the segment. "I've avoided it. And I started thinking, 'Wow, if I've put it off, how many other people have put it off as well?'"

Although 40 is the age at which the National Cancer Institute recommends women start getting annual mammograms, there has been some controversy in recent years over that number. In 2009, a government task force suggested a more lenient mammogram routine, that healthy women with little family history of breast cancer wait until 50 to get a mammogram and then only get them every two years. The task force reported that, though women should have the breast-cancer talk with their doctors at 40, many women who strictly follow the NCI guidelines experience false positives and non-life-threatening conditions.

Still, situations like Robach's do happen. Her experience will be a wake-up call to others who have put off at least talking with their doctors about breast cancer. "No excuses," she said of her mammogram. "It is the difference between life and death."

[Image via AP]