Semi-Homemadelifestyle mogul Sandra Lee announced that she has breast cancer today. She told Good Morning America's Robin Roberts in an emotional interview [video] that she found out in March, when she had been doing a photo shoot for People's Most Beautiful issue. "I walked off the set, and 20 minutes later my doctor called and told me I had breast cancer," Lee recalled. "I didn't even cry, I was stunned... You know, and that's just how fast life turns. It turns on a dime."

Lee said she will get a double mastectomy this week. She said her physicians recommended the procedure, "And so I said, 'OK. If I'm going to have a mastectomy, am I supposed to just get one done?' Both the radiologist and the doctor said, 'You're a ticking time bomb.' And they both said, 'You need -- I would just get them both done.'" She added to People, "I never want to go through this again."

The 48-year-old self-made entrepreneur, who is also the companion of Governor Andrew Cuomo, had gone for a routine mammogram, which led to the diagnosis. According to People, "Lee - who has started to document her thoughts and medical appointments in a no-holds barred video diary - was diagnosed with DCIS (ductal carcinoma in situ), a common noninvasive cancer contained within the milk ducts that can become invasive over time if left untreated."

Lee said that she called her sister first then Cuomo, "I think he was as stunned as I was." She said he's been "extremely supportive... He's going to be in the operating room with me."

Cuomo issued a statement:

"A few weeks ago we received terrible news. Sandy shared with me that she was diagnosed with breast cancer. I was devastated. After the news what followed was a blizzard of doctors visits, tests and discussions of treatment options. Sandy is young for her diagnosis, she has no family history, she is healthy and had no symptoms or signals that she was in danger. She has been diligent about going for check-ups and thankfully this was detected in the early stages.

A situation like this quickly puts life in the proper perspective and reminds one of what’s truly important. To that end, I expect to take some personal time because I want to be with Sandy to support her in any way I can as she handles the trauma of her operation and the pain of the recovery.

For those of you familiar with Sandy’s life story it will not surprise you that she has met this latest challenge with determination, resolve and grace. She never ceases to amaze me. While she has kept her illness private until now, Sandy has bravely decided to speak openly about her illness in order to remind women of the potentially lifesaving power of early detection. I fully support her decision.

With heartfelt gratitude for your kind wishes and support, Sandy and I hope and pray to bring you good news of her strong recovery soon."

Lee told Roberts, who battled breast cancer herself, that she wants to tell younger women to get mammograms at earlier ages, "Girls in 20s and their 30s just have to know. And I don't want women to wait. And that's why I'm talking … If it saves one person, and makes one more person go get a mammogram, and if they're sitting down right now watching this, don't watch this TV. Go pick your phone up, and call your doctor and get your rear end in there and get a mammogram right now. You hear about it and it is always someone else, it's a friend that you sent flowers to and you wish well and that you watch every single day like I watched you. And you were my hero. But I never thought I would be dealing with this."

Lee also tested for the BRCA1 and BRCA2 genes, whose carriers have an increased chance for breast and ovarian cancer, and found she was negative. Angelina Jolie had a double mastectomy in 2013 after finding she had the BRCA1 gene and later decided to have her ovaries and fallopian tubes removed.