Giuliana Rancic

Giuliana Rancic has been diagnosed with breast cancer, she revealed on Monday's Today show.

"Through my attempt to get pregnant for the third time, through IVF, we sadly found out that I have early stages of breast cancer. It's been a shock," she told Ann Curry.

VIDEO: Giuliana Rancic explains why she discussed her miscarriage on her show

The E! News  host has documented her quest to get pregnant on her reality show Giuliana & Bill. In the Season 4 finale, she and husband Bill Rancic went to Denver for an IVF treatment.

"This doctor said you need a mammogram and I said, 'Why, I'm 36 years old, I'm too young,' and he said ... 'I will not get you pregnant if [there's] possibly the small risk you have cancer.' So I went and got a mammogram ... they called me the next day and said we need you to come back, we see something," she said. Upon hearing the news, Rancic says, "It was like incredible instant sobbing and the world just crashed around me."

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Rancic says she's undergoing surgery this week and then undergoing 6 1/2 weeks of radiation. The couple, though, is not giving up on their hope to have a baby.

"I still want that baby. I always said there was some master plan of why IVF didn't work, why I never got pregnant, and now I truly believe that God was looking out for me," she said. "Had I gotten pregnant, a few years down the line I could be a lot sicker."

E! News released a statement following the announcement. "On behalf of her E! family we are sending our love and support to Giuliana and applaud her for sharing her recent breast cancer diagnosis in the hope that it will encourage women everywhere to take necessary and preventative measures."

Watch Rancic's interview with Curry below.

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