Avoiding the set...

[LRAO]

I know one of the poker basics is that when you flop a set, you will either win a big pot or lose a big pot (to a draw).

So my question is, has anyone picked up clues as to how to avoid going up against a set?

A classic example would be, say, I'm hold AK and someone with 55 limps before me. I raise, he calls.
Flop:

K 8 5

At what point (flop, turn, etc.) does one dump their TPTK or top 2 pair (let's say the flop was AK5) Or is this just one of those unavoidable scenarios?

Thoughts?