Celebrity chef Sandra Lee, the partner of Gov. Andrew Cuomo, has been diagnosed with breast cancer, she announced on Tuesday.

Lee will undergo a double mastectomy, she told Robin Roberts of "Good Morning America."

Cuomo has been "incredibly supportive," Lee said. He issued a statement saying he is "devastated" and said he will take some personal time to help her recovery.

Lee said she received the diagnosis 20 minutes after doing a photoshoot with People magazine's "Most Beautiful People" issue. "I didn't even cry," she said. "I was stunned. That's just how fast life turns. It turns on a dime."

New York City Mayor Bill de Blasio issued a statement on Tuesday saying he and his wife, Chirlane McCray, "admired [Lee] greatly" for making her diagnosis public. "We know their family is strong, and that Sandy will have the all the love, support and good humor she could need in this moment," de Blasio said in the statement.