"I am proud of Amy for sharing her story," the E! News host said about her fellow TV personality, whose cancer was detected after she underwent a mammogram on Good Morning America as part of Breast Cancer Awareness Month in October.
Rancic continued: "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."
"That day, when I was asked to do something I really didn't want to do, something I had put off for more than a year, I had no way of knowing that I was in a life-or-death situation," Robach wrote in a post for ABC News about her decision to have a mammogram on the air. (The network news health-reporting trend was pioneered by Katie Couric, who lost her husband to colon cancer, undergoing a colonoscopy on the air in 2000.)
"I was also told this, for every person who has cancer, at least 15 lives are saved because people around them become vigilant," Robach wrote. "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."
She is scheduled to undergo a bilateral mastectomy on Thursday, followed by reconstructive surgery.
Rancic revealed in October 2011 that she was battling cancer and she eventually underwent a double mastectomy as well. The wife and mom has since become an advocate for breast cancer education, speaking about the importance of preventive care and regular screenings.
She told CBS News last month that life post-cancer involves "blood work every four months and they test everything to make sure I'm OK—and so far, so good."
Catch Giuliana week nights on E! News at 7 p.m. & 11:30 p.m.