Betsy Duncan Smith, the wife of former Tory party leader Iain, has spoken of her health battle for the first time as she called for the NHS to use dogs to diagnose cancer.
Mrs Duncan Smith, who was diagnosed with breast cancer in in 2009, told the Daily Telegraph her husband had "coped brilliantly" while she underwent courses of chemotherapy and radiotherapy to beat the disease.
She said: "I remember reaching 50 and thinking, 'Goodness, life is good, I'm so lucky', and then four months later the wheels came off.
Her battle focused her on working with charity Medical Detection Dogs, where she is a trustee. She urged the health service to consider using dogs to assist in diagnosing cancer earlier, because "they can beat any cancer detection device, and they are so much cheaper".
"NHS England has just announced a new push on early detection of cancer and I want to say to them, don't write us off. Let our dogs be part of your work. Dogs are used to save lives elsewhere - at airports, around explosives, even checking out the House of Commons. Why this reluctance to use them in medicine?"
The charity is currently running tests to determine the accuracy of their trained cancer detection dogs and have appealed for breath samples from young women.
One of its dogs, a Labrador called Daisy, won recognition from another animal charity for identifying a reported 550 cases of cancer.