A Norfolk farmer has departed on a 240-mile trek around the county to raise money for cancer charities – and to prove that a diagnosis should not mean the end of an active lifestyle.

Tim Farnham, from Scarning near Dereham, headed off from Norwich on Saturday and hopes to complete the circular route in 20 days to generate vital funds for the Big C and the Norfolk and Waveney Prostate Cancer Support Group (NWPCSG).

But along the way he also hopes to raise awareness of the importance of exercise, a positive outlook and early testing in order to maximise sufferers' chances of beating their illness.

The 59-year-old was diagnosed four years ago with chronic lymphocytic leukaemia which he said may ultimately require chemotherapy, but at the moment does not need treatment – although it leaves him fatigued after exercise.

In Autumn 2010 he was told he also had prostate cancer after going for a prostate specific antigen (PSA) screening test which revealed a potential problem and prompted a swift diagnosis and successful surgery in February 2011.

Mr Farnham said: 'The fund-raising is important but, for me, at least 50pc of what I'm trying to achieve is to get the message out that when people get a cancer diagnosis it does not have to be like a train hitting the buffers.

'Some people have a very difficult experience, but for a lot of people if you are diagnosed early and are found, like me, to have a form of cancer that can be treated quickly then you have a chance for a good quality of life.

'There is lots of evidence that if you take normal, moderate exercise and look after your diet, don't smoke, don't work too hard... if you do those things you can improve your life chances enormously. If you were told there was a pill you could take which would improve your chances by 50pc and there were no side effects, you would take it. This is no different.'

Mr Farnham departed from the steps of City Hall on Saturday, for the first leg of his journey, heading towards Surlingham. His route encompasses all corners of the county, including Great Yarmouth, Diss, Swaffham, Brancaster and Cromer before returning back to Norwich.

'I have done a lot of long-distance walks so it is something I am reasonably comfortable with,' he said. 'I need to be fit and I want to tip the scales in my favour if I can.

'None of us know what's going to happen in the future, but at the moment I am in good shape. Even if I have to stop this time, I will start over again when I am fit enough, so I am completely confident I will finish.'

Mr Farnham's wife Gail said: 'When he came home and said about the leukaemia that word was a total shock. It was two weeks before we got over the diagnosis. You immediately think it is a life sentence, but luckily Tim had a slow-moving type. But then it was followed up by the prostate cancer diagnosis, which was a double whammy.

'But he has always been positive and educated enough to investigate all the scenarios and make the right choices. Everybody is very proud of him.'

Among the supporters who waved Mr Farnham off at the start of his journey was Martin Bell, the former BBC war correspondent and independent MP who is now the patron of the NWPCSG. Mr Bell, known as 'the man in the white suit', said he had a brush with prostate cancer himself when some suspect PSA test results caused concern, but he was subsequently given the all-clear.

He said it was crucial for men to undergo tests to catch the disease early.

'Apart from anything else, this is a life-saving initiative,' he said. 'People are alive now who would otherwise be dead because of the publicity this generates, and the knowledge that people can get treatment if they get the diagnosis early.'

Mr Farnham has already raised about �4,000, but hopes to push that total as high as possible. To donate, or to join Mr Farnham on a section of the walk, contact him on rookfarn@googlemail.com or visit www.walknorfolk.wordpress.com.