I have used some canned goods that were pretty old (3-5 yrs), and they were fine.
On the other hand, I had a 14 oz. can of tomato paste that was only a few months past the use-by date, and it exploded in my pantry.
I think it probably got dropped and busted it's seal. I didn't discover it until the stuff was dried on.
They say the food is all right as long as the seal isn't broken (top of can should not pop when pressed), but I opened some tuna once that tasted kind funny...not spoiled, but old. I think that was the deal with your pears, Charlie. Since none of us are starving, my advice is to throw it away.
I actually have a big can of pears and another of peaches that I've had several years. Maybe I should look them over.