The 'Misery' actress - who previously battled ovarian cancer in 2003 - has undergone surgery to remove her breasts following the detection of the disease, and reveals she will not be having any radiation or chemotherapy.
She told People.com: "After much consideration, I underwent a double mastectomy. Luckily, I don't have to undergo radiation or chemo. My family call me Kat because I always land on my feet and thankfully this is no exception."
The 64-year-old Oscar winner is now "looking forward" to working again after doctors told her she would recover.
She said: "My doctors have assured me I'm going to be around for a long time. I'm looking forward to getting back to work doing what I love."
Kathy previously kept her ovarian cancer diagnosis secret because she wanted to keep working, but said should cancer return she would not be quiet.
She said earlier this year: "I admire people who have been open, like Melissa Etheridge and women I see walking around facing it without wigs and all of that stuff. I think I'd be more courageous next time."
Related Video: The latest showbiz news