Does Bible allow moderate life extension?

Since the dawn of humanity, our life expectancy has greatly increased . It went from 30 to 80 years in developed countries. What if we collectively manage to eradicate all diseases (like cancer for example)? Humans will still be dying from accidents and murders, just not from diseases. Does Bible allow us to cure all diseases if it is done ethically? Or should Christians be protesting against any attempts to improve our medicine (like cancer research)? I've heard an argument that all attempts at life extension is "playing God" and most medical advances in one way or another extend our lives. I wonder if it is correct.