Actually they don't after the normal chemo therapy. Hence why Armstrong got a different treatment according to Wikipedia!I'd say Lemond ahead of Armstrong. Sure the chemo is tough, but afterwards the normal levels return (and then some in his case). But when you are shot through and through there is lead leaching into your bloodstream.
Three names come to mind: Gregory James LeMond
Lost somewhere between a third and two-thirds of his blood volume in his hunting accident, saved by a combination of his huge heart and lungs and the fortuitous presence of a police helicopter close to the scene when twenty minutes from death.
Returned to racing in 1987 with dozens of pellets still inside him (he still has some by his heart) though the limited race programme and poor results continued in 1988, before he finally showed some form in the last week of the 1989 Giro.
Roglic was a brilliant case of not coming backSpeaking of people with very serious crashes, Kai Reus made multiple comebacks, though he sadly never became a star.
Annemiek van Vleuten has had more setbacks during the past year than most riders have in their whole careers.
Roglič had a great comeback after his failed first career.
Actually, it was stage 4 cancer for Armstrong I think -- metastasized to abdomen, lungs, and brain. In addition to the extensive chemo regimen (prior to the regimen), he had to have brain surgery to remove tumors. Lemond's injury was different but also incredibly debilitating. He took a chestful of turkey shot, and some of the pellets couldn't be removed. Both of those comeback stories are amazing, as are others in the sport.Armstrong. I cant see how anyone could compare injuries to stage 3 cancer.
I think Froome deserves a mention up on that list. Yeah, he may never win a top end race again, but what he came back from to actually race again is surely up there.