> Have you ever been in a situation like you describe?
Knowing that death is certain? Yup. In fact I never expected to live as long as I've lived.
> I think human instinct kicks in.
Well, there's some kind of motive, sure; but "human instinct" implies that all humans have it built-in. I'm a counter-example, and I'm not alone in that.
> It takes a true belief there is no hope to actually want to die rather than fight.
Oh, I don't want to die. I'd struggle, e.g. if I was faced with a murder; might as well have a go. But I wouldn't struggle like the folk in TFA to get access to unlicensed experimental cancer treatments.
I didn't read the first article, so I don't have the full context. It makes a huge difference if you have people counting on you. It makes sense to struggle for the sake of other people.
[Edit] Arguably, participating in a trial is struggling for the sake of other people; but that's not the attitude I got from TFA.