Lance Armstrong has a good summary on cancer in his book 'its not about a bike'
he basically says on the 'fighter' issue that the essential truth to remember about cancer is: people die. Some people do all the right things, have the right spirit etc and they die. Other people don't seem to have the same toughness but they survive.
Also 'survive' is the word he uses, he says you don't 'beat' cancer, you survive it. The doctors and the chemicals they use to assault the cancer (and your body) are what do or don't beat the cancer....all the patient can do is 'survive' the treatment.
He acknowledges himself that he was a pretty long shot (he had advanced cancer throughout his lungs and brain as well as his testicles) and had to have some very aggressive treatment, and probably his cycling training and mental toughness helped him to take more harsh treatment than other people could have done, but even then the fact he survived was a mixture of luck and the skill of the people he had treating him.