By Jane Elliott
Health reporter, BBC News
Four years ago, doctors gave David Hillier just two years to live after diagnosing him with advanced prostate cancer.
David says his hobby gives him a sense of purpose
Determined to fight the disease, David was willing to explore every radical and experimental treatment.
Despite being warned that a course of chemotherapy might do little to improve his prognosis, he persisted.
David eventually found a doctor at the Middlesex Hospital willing to give him the six-month course of treatment.
Then he spent eight months at the Memorial Sloan Kettering Hospital in New York, having a specifically targeted type of radiotherapy currently only carried out in the US.
A doctor there encouraged David - who, at 41, is relatively young to get prostate cancer - to do as much exercise as possible.
So he took up cycling - in a big way.
David decided to set himself goals - competing in races and raising charity cash.
He took part in New York's Five Borough's race - a 42-mile trip - and recently competed in the gruelling Etape du Tour - a 118-mile ride along the infamous Gap to Alpe d'Huez mountain stage of the Tour de France.
And the hard work has paid off. Not only has David raised more than £250,000 for the Prostate Cancer Charity, but his cancer has been undetectable for almost a year now.
He said: "I still don't know how much time I've got left on this earth. In fact, I've stopped asking my doctors now because they don't know either.
"The odds suggest not as long as most people. My heart tells me that I'm going to be the lucky one, the miracle man, if you like.
"I don't know if that's true, but in the meantime, I'm going to stay positive, stay active and keep giving myself things to stay alive for.
"I wouldn't be able to look my wife and daughters in the eye if I did anything else. "
David, an economist, often cycled 80 miles a day preparing for the French race, but did not complete the circuit because he was not fast enough.
The race, which is open to amateur cyclists and takes in three mountains, has a strict time policy as the roads need to be re-opened to cars.
But David, who was eliminated just after the half-way mark, said he had enjoyed the experience.
"The good thing about taking part in rides like this is that it gives me something to aim for. Something to stay alive for. "
Where is the prostate?
David only found out about his cancer after it was pinpointed during tests for repetitive strain injury.
"Prostate cancer is obviously a man's disease, but everyone should be aware of it and the signs that indicate its early stages.
"If you are a woman with a father, a brother, a son, or a husband it's as much an issue for you as it is for the man in your life.
"If you are a man, then you have to act like a real man. Know what your prostate is, what it does, where it is, what the symptoms of prostate cancer are and get yourself tested regularly.
"Think you're too young? Think that it can't happen to you? Well it can. It happened to me. "
Tania Ross, lead nurse of the Prostate Cancer Charity helpline, said a worrying number of men were unaware of the disease and many unable to even say where their prostate was.
"We find when we do our surveys that many men do not even know where their prostate is located, or that even men are the only ones to have one.
"So when we have our campaigns we have to start at the most basic levels."