Bill and Giuliana Rancic. (Jamie McCarthy/Getty Images)

Rancic’s husband Bill tweeted, “Thank you for all ur love & support today. G is reading all your messages. She will win this fight, I PROMISE, & be back better than ever!”

In an interview with Ryan Seacrest, the 37-year-old E! News host said she went public with her diagnosis to give other women the push they needed to get tested. Despite being extremely nervous about delivering the news, Rancic said she was relieved it was done.

“I feel like such a heavy weight has been lifted off my shoulders,” Ranic told Seacrest of sharing her condition. “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.”

Rancic told “Today’s” Ann Curry that the cancer was detected early. She will undergo surgery this week, then radiation treatment.

E! released a statement, saying they “applaud her for sharing her recent breast cancer diagnosis in the hope that it will encourage women everywhere to take necessary and preventative measures.”

Rancic’s celebrity friends and co-workers have offered well wishes on Twitter.

Lea Michele: “Sending love to @GiulianaRancic today. You’re a very strong woman. Thinking of you. Xo.”

Ryan Seacrest: “Take a second to send good wishes to @GiulianaRancic, she's had a tough couple days. We’ll all be w/ u thru surgery jules! Love u.”

Kelly Osbourne: “i just want u 2 know i love you & that im thinking of u! u r a strong women & ur going 2 beat the [expletive] out of this cancer!!!”

Khloe Kardashian: “I just heard about Guiliana Rancic :( my prayers, positive thoughts and love are with her! Stay positive and stay strong! Muah! Xoxoxo.”

Jackee Harry: “My Thoughts & Prayers Are w/ Guiliana Rancic. #StayEncouraged.. xoxo's.”

Angie Harmon: “ @GiulianaRancic we all support you 100%!!! you are not alone &we all love you! You &yours r in our prayers!”

Bethenny Frankel: “What you're going through is all that matters [Giuliana and Bill.] It puts everything in perspective. Love&prayers are with you.”