That could be said of anyone, not just an 86-year-old. I recall the story of a female physician stationed at the South Pole who had to be rescued after she discovered and self-treated her breast cancer until a plane could be sent in to rescue her. She was only 47 years old.
http://www.cnn.com/2009/HEALTH/06/23/obit.jerri.nielsen/index.html?eref=ib_us
Pictures from his Twitter feed from 11/29 show Buzz Aldrin to be in pretty good shape and in apparent good health.