The presenter, who has had stints on the daytime panel show since 2000, spoke to Kate Thornton on White Wine Question Time about her experience of cancer, having also lost her mum and her sister to it.
She said she was diagnosed with 'a particularly fast spreading dangerous, aggressive' cancer, but was lucky to have caught it in time, but still said the treatment she had was 'dreadfully unpleasant'.
She told Thornton: "It was absolutely hideous, that kind of chemotherapy. There's lots of different levels as well. The one I had was properly toxic. It was awful. It was terrible.
"You kind of you realise what your levels are, I could tolerate that. And I could put up with it because I knew what it was doing.
WATCH: Carol McGiffin on surviving breast cancer, her age gap with husband Mark, and her issues with social media and privacy
"It's hard to believe that something so toxic, and that makes you feel so ill when you didn't feel ill. The treatment makes you feel so sick, it's hard to believe that that is actually making you better. But it does, apparently. So I just thought: 'I'll just get through this.'"
McGiffin, known for her straight talking, was diagnosed with breast cancer in 2014. She had not long left Loose Women at the time and wasn't working apart from writing columns where she did not mention her diagnosis.
She also revealed that some friends and some people on social media were a 'annoyed' and 'upset' with her when she did finally speak out about having cancer.
But the former Celebrity Big Brother contestant said she had to deal with it in her own way. "I'm not one for self pity for a start," she said. "So I never really said: 'Why me? Poor me, this is not fair.'
"I just thought: 'I've got it. Loads of women get diagnosed with it, loads of women have it, a lot of women don't survive it. A lot of women find it easy, there's different types of cancer.'"
She talked about spending a lot of her recovery time at her brother's in Kent, where she could be in the open and away from London, though she was travelling back to the city every other week for chemotherapy.
She said: "It was nice to get out of London because London sometimes can feel like a really unhealthy place.
"And being stuck in a flat wouldn't have been as good as seeing fields and animals and things like that."
McGiffin said she and her husband 'just dealt with it' and stayed in easting biscuits and watching box sets.
"You've just got to do what you have to do, and carry on living your life as normally as possible. I didn't want to be taken over by cancer at the time," she said.
She and Thornton also discussed a champagne brunch they'd had at Lynda Bellingham's on one of the last times they'd seen her before their Loose Women colleague died of cancer in 2014. They had regularly appeared on the show together between 2007 and 2011.
McGiffin had not wanted to tell her that she too had cancer, thinking she had 'enough to worry about' and also was having such a good time.
She said: "This was towards the end, so the last thing I wanted to talk to her about was was cancer because she was having a drink, and being a bit riotous!"
She said in the end she 'probably got p****d' and did end up telling her. Bellingham replied: "Oh, not you and all!"
"And that was it with cancer," said McGiffin. "It can get quite overwhelming and just take over your everything, your life and your thoughts.
"And sometimes you can't help that. But you have to get away from it sometimes and, and have a bit of fun and enjoy yourself.
"And she bloody enjoyed herself that day. And I think when I told her, it sort of took a bit of pressure off her."
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