He is, without question, one of the greatest athletes of all time. Arguably, the very best. A big part of what makes Lance Armstrong's ascent to the top of the cycling world so compelling is his fight to become a sporting icon paled in comparison to his battle to stay alive.

While honoured to be the world's only six-time Tour de France winner, his proudest accomplishment is being a cancer survivor.

It was only eight years ago his body was ravaged by the world's deadliest disease, reducing his chances of survival to a coin flip.

Tipped off by a swollen testicle that required immediate surgery, Armstrong was diagnosed soon thereafter with rampant lung and brain cancer that required post-operative chemotherapy so intense he still remembers his doctor's daunting warning.

"I'm going to kill you every day and bring you back to life," he was told.

"At the end of this thing I'm going to have to teach you how to walk again."

Hope of returning to his bike one day for a charity ride turned to prayers he'd be able to go three hours without vomiting.

Remembering the pity on the faces of nurses, doctors, visitors and even his mother as he laid in a hospital bed wasting away, Armstrong channeled the emotions to take on a courageous uphill fight that would later become his cycling trademark.

Knowing no amount of pain searing through his legs and lungs en route to Sestriere or along the Alpe d'Huez could ever compare to the daily torture he faced in the chemo ward, he says winning his first Tour de France three years later was relatively "easy."

"Cancer has given me an unfair advantage," says the 33-year-old Texan, who will share his story at a cancer fundraiser tonight at the Hyatt before making good on a promise to ride through the Highwood Pass for tomorrow's 120km Tour of Courage.

"It was a gift. It was the greatest thing that ever happened to me."

It's that sort of mentality that's helped put him at, or near, the top of a list of athletes who've truly transcended their sports to become household names.

Over the last six years the world's most famous cancer survivor has been every bit as dominant as legends like Muhammad Ali, Wayne Gretzky, Michael Jordan, Jesse Owens, Babe Ruth, Pele, Jack Nicklaus or Tiger Woods were in their primes.

Spending three gruelling weeks in the dead of summer cycling the mountainous circumference of France, Armstrong has drawn the world to his sport by hammering past all competitors with a cadence so superior most concede defeat a week into the race.

The man whose lungs used to be filled with golf ball-sized tumours now uses them to breathe life into a run that will likely never be matched.

He's so good, opponents have reduced themselves to suggesting Armstrong's performances must be drug-aided, even though he's never tested positive for steroids.

His mind, which once wrestled with the thought of having ever-threatening brain tumours extracted, possess unparalleled drive, determination and a killer instinct that became legendary in the Pyrenees, amongst other places.

Add an element of class, eloquence and humility to his well-told tale and you have the makings of an autobiography so inspirational it should be required reading for every child.

Anyone with cancer or affected by the disease should never let it leave their side.

He has a rock star girlfriend (Sheryl Crow), three kids, wealth beyond comprehension, the respect and admiration of the sporting world and more tour titles than anyone in cycling history.

Most importantly, he has his health.

And those who take such a thing for granted will have their lives changed tonight when they hear Armstrong tell his story.

It's one of the most inspirational stories ever told.

By one of the greatest athletes the world has ever seen.