Carol, 54, said that Bellingham, who died in October from colon cancer at 66, had sworn and said "not you an' all", when she told her of her own fight.
The star found a lump in her breast while on holiday in February last year and was diagnosed with a tumour in April before undergoing a mastectomy, chemotherapy and radiotherapy to overcome it.
McGiffin, 54, revealed her private battle with the disease for the first time in The Sunday People newspaper and sported short hair in photos for the paper.
"I don't want to pretend any more," she said. "I kept it a secret because I didn't want anyone feeling sorry for me.
"I feel it is over now and I've got through it. I just want to be able to go out without my hat on and for people not to be bothered. I just want my life to get back to normal."
She said her fiance Mark Cassidy, who is 22 years younger than her, had helped shave her hair off and that he had not been "fazed" by her ordeal.
In her regular column for the newspaper she added it had been "nothing more than a bad dream" and praised the NHS staff at the Royal Free Hospital in London, where she said she had at one point been placed in the isolation unit next to the Ebola ward.
"I felt as if I should keep in touch with the people who cared for me but like all NHS staff they're too busy looking after the next patient. But my gratitude knows no bounds and I'm sure they know that," she wrote.
Talking about Bellingham, Carol told the paper: "She was a bit annoyed I hadn't told her before but that was Lynda all over - worrying about others."
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