If God creates the laws of nature in such a way that people get diseases and cancers He couldn't have done it "on accident" or "unknowingly," since omniscient beings don't make such mistakes.
Therefore it must have been intentional.
It was Not intentional or deliberate that Satan and Adam willfully disobey.
Sin [disobedience] brought death into the world.
Along with sin comes sickness leading to death.
Time allows us to be born and have the opportunity to be at the future time when sickness and death will be no more according to Rev 21vs4,5;Isa 33v24.
Satan challenges all of us [Job 2v4,5] that touch our skin [health] and all will curse God. Both Job and Jesus proved [the god of this world of badness 2 Cor 4v4; Rev 12v12] Satan a liar and we can too.
So it is not the 'law of nature' but rather 'sin's law' that is to blame.
Romans 5 vs12-19
see also Romans 7v23 mentioning the 'law of sin'.