The singer and actress was first diagnosed with the disease in April 2010. She underwent six months of chemotherapy and a mastectomy before being declared cancer-free in December 2010.
The 52-year-old has said that the diagnosis is incurable, but she is determined to continue "fighting" the disease.
"OK, it's not curable. But the doctors have promised me the cancer is treatable, it's containable," she told The Mirror.
"I'm on medication which is controlling it, and people have lived for 12 years on these drugs. Who knows what new treatments are around the corner?
"I refuse to sit around like I've got a death sentence hanging over my head. I'm going to fight this for ever. It can get stuffed."
After she successfully battled breast cancer two years ago, the disease has now reportedly spread to her brain, lungs, liver and bones.
"It is harder this time," she explained. "Because that word has come into it... incurable. That was never there before. But there's another word I have too, a word I like. Treatable. It could have been worse. It could have just been incurable.
"Sometimes when I think about it, I get that feeling of panic in my stomach. Then the Bernie effect kicks in and I think, 'Oh, bugger off, get on with it'.
"It's like I've got two different people sitting on my shoulders, like Jiminy Cricket. But the strong one always wins. The positive voice always manages to push the panicky one off."
Nolan added that she was first diagnosed in the summer, but decided to keep it a secret. However, she changed her mind after discussing cancer with Lorraine Kelly on ITV1 a few weeks ago.
"I was speaking to Lorraine Kelly during Breast Cancer Awareness Week and she asked me how I was. I just changed the subject, but it's that sort of thing that doesn't sit well with me," she said.
"And who knows what that sort of stress does to your health, wondering who knows, who doesn't know. I apologise to Lorraine now but I couldn't have said it then."
Talking about the battle ahead of her, Nolan added: "I'm not living in denial. I know exactly what's going on and what could happen. And of course there are moments when I feel scared.
"I wake up in the morning bright, happy, and then it hits me. I've got incurable cancer. But then I think, 'Oh well, feck it. Get up and get on with it'."
The Nolans recently announced plans for a farewell tour in 2013 with members Bernie, Coleen, Linda and Maureen.