US TV anchor Amy Robach learns that she has breast cancer weeks after her much-talked about mammogram test on air.

In an essay she wrote for ABC News, the Good Morning America host recounts how she learned of the disease during a follow-up examination weeks after the live mammography exam on October 1, as well as the events that followed.

"I was alone that afternoon, never thinking to bring anyone with me, never thinking that day would be life-altering," Robach writes. "My husband was on a business trip and my parents live across the country, but that night everyone flew into New York City and we started gearing up for a fight."

In the same essay she reveals how she plans to get treated -- a bilateral mastectomy scheduled today, November 14, followed by a reconstructive surgery.

She also reiterated in the essay the words that fellow host Robin Roberts told her that made her do the on-air test, "(F)or every person who has cancer, at least 15 lives are saved because people around them become vigilant. They go to their doctors, they get checked."

"I can only hope my story will do the same and inspire every woman who hears it to get a mammogram, to take a self exam. No excuses. It is the difference between life and death."

Robach joins the roster of celebrities who has survived breast cancer, including E! News host Giuliana Rancic who lauded her for both the live mammogram test and the public announcement of her disease.

"Her bravery will encourage countless women to be proactive about their own health. As tough as her journey seems now, she will emerge a stronger woman and hopefully find comfort in having helped others," Rancic comments.

Prior to Robach's mammogram, a few live health tests have been aired on various TV networks, starting with Katie Couric who had colonoscopy following the death of her first husband from the same disease in 2000. Last week, Today hosts co-hosts Matt Lauer and Al Roker underwent prostate exams on air.