In the spring of 2007 Simon Bush, 50, from London, had to accept that he was probably dying.
Simon was in constant pain
The successful banker had been diagnosed with aggressive prostate cancer, which was at an advanced stage.
But then he was signed up to a trial of a new drug called abiraterone.
"I had just completed six months of chemotherapy, which had not affected the disease, which was growing quite rapidly," he said.
"I had prostate cancer in the soft tissue, and in my bones. I was in fairly severe pain at that stage, on painkillers daily.
"As every day went by I was less and less able to do anything of any active nature.
"The prognosis was very poor. I had effectively failed all the standard treatments.
"I was referred to the Royal Marsden, and started the drug in May 2007."
The progress of prostate cancer is measured by monitoring levels of a protein - prostate specific antigen (PSA) - which is produced by the cancer.
As he started treatment, Simon's PSA level was 100 nanograms per millilitre of blood - around 35 times the norm for a man of his age. In his bones, it was much higher.
Simon and his wife Nana have been able to travel the world in the last year
"Within a week of starting the drug my PSA level had dropped to 38, and three weeks later had dropped to eight. A month after that it was four, which is virtually normal.
"Although it took me a while to believe it, my pain virtually disappeared within two to three weeks of starting the trial drug, and I stopped painkillers completely a month after taking the drug.
"It had a phenomenal impact on our day-to-day living.
"All I know is that I could do virtually nothing back in April a year ago.
"Today I am about as active as I could possibly be.
"We have travelled all over the world, and I have actually been skiing, which, given the severity of my bone disease 14 months ago, is hard to imagine.
"There are virtually no side-effects at all. It is a very simple drug to take. The only thing is that I have put on a bit of weight."