I'm the spitting image of my paternal grandfather in so many ways (including fiscal habits, sense of humor, etc.). He passed away at age 80 from pneumonia, but had some prostate/bone cancer issues starting at 75 (which suddenly appeared after not going to the doctor for about 35 years). He was starting to show symptoms of alzheimers and dementia in his final 6 months or so. He was a plumber for a number of years, so I don't know if those were the result of some of his job hazards (sweating lead joints, various solvents, etc.), or nearly all genetic.
My grandmother (his wife) lived to be 88 in actually very good health, despite having most of a lung removed from a rare lung disease in her 40s and having terrible kidneys from terribly strong medicine given to her from said lung treatment.
I'll be planning financially to make it to the early-mid 90s with my future wife and will be doing everything I can to enjoy life while also trying to prolong it as long as possible, but realistically think if I make it to 84 with a clear mind I'll be damn happy, and consider anything beyond that as "borrowed time". I know that medicine will continue to make amazing advances, but I think most of the hope of "a cure for _____" is just wishful thinking for the most part, and that the realities will be that some drugs for more of the symptoms rather than cures will be the prescriptions available.