McCain's Medical History: What Will It Show?

May 22, 2008 — -- The plan by Sen. John McCain's campaign to release his medical records this morning has many wondering just what they will reveal about the 71-year-old war veteran.

Voters may be concerned about how McCain's health will hold up over his term if he is elected in November, given his history of melanoma, as well as the possibility that his age leaves him more prone to dementia.

McCain has been labeled by some as "too old" to run for president. However, aside from moderately high cholesterol, for which he takes medication, doctors say McCain is in exemplary shape for his age.

"The actuarial tables say if you make [it] to 71 in overall good health, your life expectancy is about 16 years. That would be to about to age 87," ABC News medical editor Dr. Tim Johnson told Charles Gibson on "World News."

But, Johnson noted, McCain's continued mental acuity is a much more difficult question to answer especially because increasing age is the single biggest risk factor for developing memory loss and dementia.

Dr. Gary Small of the University of California, Los Angeles, told ABC News that McCain should undergo screening to ensure that he does not have an onset of dementia -- the risk of which is around 20 percent for someone his age.

But some argue that age may, in fact, be an advantage. An article in Tuesday's New York Times documents research showing that, with age, the brain may take in more information to make a wiser decision.

When asked whether McCain's age would give him a mental handicap, Small replied, "Nobody's perfect."

Another concern is McCain's history of skin cancer.

McCain had a melanoma roughly the size of a nickel removed from his left temple in 2000 -- a surgery from which he still bears a prominent scar.

However, given that McCain has had no further skin cancer in the last eight years, most physicians seem to agree that the chances of a fatal melanoma are minimal.