Sir Rod Stewart had to have a "three month intensive course of radiation" therapy to treat his prostate cancer because he had an aggressive form of the disease, his wife Lady Penny Lancaster-Stewart has revealed.

Penny Lancaster and Rod Stewart

Penny Lancaster and Rod Stewart

The 74-year-old music legend was diagnosed with the potentially-fatal illness two-and-half years ago and doctors discovered that the tumour had moved outside his prostate gland and so removing it wouldn't cure him.

Instead, Rod had to go to a London hospital everyday for three months to receive radiation therapy and luckily for the singer the treatment worked.

Appearing as a panellist on 'Loose Women', an emotional Penny said: "In July he got the all-clear there's no trace at all so that's really exciting news.

"When it happened we were in London and Rod is very up with his health, he doesn't believe in retirement he wants to go on forever so he's always going to get screenings and tests ... Rod had a few symptoms, went and had his PSA tested it was slightly elevated and things started moving quite quickly, the results and the numbers, so they said, 'Look, we best do a rectal exam.' They did find a lump and then they couldn't ignore it.

"We got the shock news that it was cancer ... it was quite aggressive and it came on really quickly ... With Rod it was an aggressive one and instead remaining in the gland it had left the gland and travelled to the outside tissues. That was another scary moment where he had to have more invasive tests and scans if it was anywhere else, if it was secondary in his body, which was the most frightening test of all. But it hadn't gone [anywhere else]."

Sharing his treatment programme, the former model added: "It's been two-and-a-half years now, but the positive news is we caught it early enough. Knowing it had travelled outside we couldn't have the gland removed, so he had to have a three month intensive course of radiation, travelling into London the same time every single day, going to the clinic, Rod's never done one day or one week the same his entire life so he put a positive spin on it. In the clinic the nurses set up a little room for him and he would sit there and say, 'This is my day in the office.' And he was extremely positive."

Whilst Rod was fighting the cancer he and Penny, 48, made the decision not to tell their two young sons, Alastair, 13, and Aden, eight, that their dad was ill, but the ' but the 'Maggie May' hitmaker did have the support of his six grown-up children.

She said: "We told the older ones but two-and-a-half years ago little Aidan was only five or six, it would have been too much for them to understand. When daddy finally told everybody the good news then we told the little ones ... Things are fantastic now."

Rod made an appearance on the UK TV show in a video segment to urge all men, especially those over 50, to go and be tested for prostate cancer and forget about the embarrassment of the rectal examination because a "finger up the bum" could save your life.

He said: "Hi my girls on 'Loose Women', just a few words about prostate cancer I've just been given the OK. Guys, please, get down to the doctors and get tested, it's a rotten disease, it gives you no warnings, no symptoms, unless you go to the doctors you don't know if you've got it. So finger up the bum, no harm done!"