I guess it just depends on how much you drive it.
I change the brakes on the Buick every fall. New rotors every other fall.
My KVR cross drilled were on the Buick for close to 55K+ and came off without drama. (Replaced the pads with a second set of the Bendix TitaniuMetalic, BTW.)
I took the drums off as well last fall. At over 110K, probably closer to 115K. I suspect this was the first time the drums were off the car. I'd say 50% of the lining was still on the shoes, so I sprayed in the cleaner and put the drums back on.
TB
All measurements in miles.