Mother with alzheimers has stage 4 lung cancer thats mestasised and broke her hip what's the outcome she doesnt seem real sick?

My grandmother had cancer and Alzheimer's she never got sick from the cancer,but after she fell down the stairs everything went downhill she died 3 wks later,Don't know if her body just couldn't handle all of the stress,or if it was the cancer kicking into overdrive.either way I hope the best for her. All people are different some a troopers some aren't.