You would destroy any inheritance your family might get, or which could be donated to a cause saving a dozen lives, over a 5% chance you don’t die from cancer specifically, which might make you feel unbearably bad until you DO die? Like much worse than you already feel? That’s insanely irrational.
Edit: and all of this is before the psychological implications of knowing your time is almost up. People would rather have burnt skin removed by a painful grinder than painless maggots because bugs and being eaten are so psychologically scarring most people won’t even consider it until they experience the pain of the flesh grinder work. People won’t think rationally anyways until it’s much too late.
Sorry what’s the inheritance logic here? Are you talking about life insurance or something? Otherwise, and again presuming the cure doesn’t work which seems absent from your assessment as a possibility, how would it affect someone’s inheritance?
My general understanding is life insurance almost never actually pays out, and if it does it’s after a long fight and for less than you signed up for, and in any case should typically not be the largest portion of your inheritance.
That all aside, taking a risky but possible option that may mean survival, as a conscious and informed decision, even if aware it may void a possibility of a life insurance payout, doesn’t seem like a decision we have more right to make than the person affected by it.