"I feel like such a heavy weight has been lifted off my shoulders," she admitted on Monday's E! News to longtime friend and co-anchor Ryan Seacrest, whom she had just shared the news with last night. "I've been keeping this secret from a lot of dear friends for a while now and it's nice to get it out there and not hide anymore."
Via satellite from New York, Rancic admitted that the decision to go public "was a difficult one." But once the celeb thought about all the women she could inspire and perhaps educate—regular breast exams are a must, ladies!—she knew there was nowhere to go but in front of the cameras.
"There was a long period of time where I thought I was going to hide this from everyone, that I didn't need to tell anyone," Rancic revealed. "And then as time went by, I would see friends of mine that didn't know, and I would think, 'God, I wish I could let her know what I'm going through,' so that she goes and gets checked."
"I started realizing I could be an example for women to not just be aware of breast cancer but to act on it," she told Seacrest. "To make an appointment, to give themselves an exam. Because truly, Ryan, the bottom line is, the earlier you find it, the better chance you have of survival.
"So that's my situation. I'm going to survive, I'm going to be just fine, I'm not broken, but that's because I found it early."
Rancic explained how her cancer was diagnosed following a mammogram that she at first didn't even want, but that her IVF doctor insisted upon if she was going to keep trying to get pregnant.
And that Today interview was no piece of cake, even for the seasoned TV personality.
"Right before I went on, I was such a nervous wreck," she recalled. "Ann gave me tissues right before we started and said, 'Keep these under your dress.'" Rancic worried, though, that people were going to feel sorry for her.
"[Husband Bill Rancic] came over and said, ‘Be yourself, just tell your story and help women. Show that you're a positive role model, that you're strong and that you're getting through this. Don't cry. It's OK, honey, you can do this.'"
"He was such an amazing support at the last minute," Rancic said of her hubby.
The perennially busy TV star is going to be taking some time off while she undergoes a lumpectomy and radiation therapy, but she warned Seacrest not to get too comfortable without her—either on the air or behind the scenes.
"Can I use your closet space?" he teased. "You have a ton of space for your shoes and stuff and I'm tight on space...Can I borrow your assistant? Something!"
"No, don't touch my clothes, but you can have my parking space for the week!" Rancic laughed. "You really need more than four assistants? Leave my assistant alone!"
In the meantime, the entire E! family is wishing Giuliana a full and speedy recovery!