It's an interesting part of the human psychology @CRM. I'd love to understand it from a psychological point of view.
I respect everyone's choices when it comes to their own bodies, the caveat being please do thorough and proper research. I can recall one member of this forum who chose not to have any further treatment whose cancer returned. I respected her honesty when she expressed her regrets.
It's the latter that's the ultimate for me. If you choose little or no treatment and your cancer returns, possibly fatally, will you have no regrets for your earlier decision? If the answer truly is yes, I respect that. However you're a stronger wo/man than I Gunga Din!