I can't run but I can swim. So I'm entering the Marathon Swims 1k challenge on 11 November at the London Aquatics Centre to raise £500 for Cancer Research. My brother Donald recently died of pancreatic cancer, so I'm doing this in his memory. And as a swimming obsessive, I want to put all my hours in the pool to some use. Cancer is an exquisitely ingenious and devastating disease that rips individuals and families apart. Every day around 450 people die from cancer in the UK. 1 in 2 people born after 1960 will develop some form of cancer in their lifetime. The more we know about it - its causes, its manifestations and its variations - the better we can treat it and beat it. But we're still on a voyage of discovery. So please give what you can. Or at least come and hold my towel. Cheers.