10/17/2011 at 08:00 AM EDT
Giuliana Rancic said Monday that she has breast cancer, having discovered a tumor during a mammogram while undergoing another round of in-vitro fertilization
in an effort to get pregnant.
The E! News and Style Network host, 37, made the emotional announcement on NBC's Today show
. She will undergo surgery this week and then have six weeks of radiation therapy.
The cancer has been detected early, and the prognosis is good, she said.
Rancic was going to wait until 40 to have a mammogram, but her IVF doctor suggested she have one now. She says she will still push to have a baby, following one IVF attempt that ended in a miscarriage
and a second that didn't work.
"I still want this baby ... because this baby has saved my life," she said. "I truly feel God was looking out after me â¦ If I had gotten pregnant later down the line, I could have been a lot sicker."
She also says her husband, Bill Rancic, has been "unbelievable. The best thing about Bill is, he lets me cry when I want to cry."
Coincidentally, Rancic recently filmed some on-the-street interviews to bust breast-cancer myths
for the non-profit Bright Pink as part of National Breast Cancer Awareness Month
, which marks its 25th anniversary this year.