Cancer can get you no matter how much money you have. You could have a private army of the best doctors on the planet and it wouldn't make a difference. And the treatment is harsh... many people who have to undergo it again and again will simply give themselves up to it rather than put themselves thru another round of chemo.
So sometimes, 'legit' western medicine is almost as much a crapshoot as any alt-medicine. I don't blame the desperate for choosing unproven methods when the arsenal of approved ones fail.