It depends. Panatomic-X has a very high survival factor. I have about 20 rolls (35mm) bought "fresh" in 1993, so probably from the last production batch by Kodak in 1987. Mostly refrigerated, but when we moved from Melbourne to Tasmania, forgotten and kept in a storage box at room temperature (in a temperate climate zone) for about five years.
It's now back in the fridge. I shoot a roll now and then, for nostalgia's sake. Results are fine, minimal fog, slower ISO (I meter at 25 and 20, not the original 32), so fairly limited in its usage - best for bright, sunny, harshly lit Australian landscapes.
Slow films appear to survive better than their high speed brethren, tho again, a year or so ago I processed four rolls of 35mm Tri-X found in a desk drawer during the clean out of a deceased friend's house. This film likely dated to the late 1970s or early 1980s. Cautious processing with, yes, D76 1+1 gave reasonable results. 3.5x5 prints from the negatives were acceptable if quite high in contrast. Not sure about larger prints, we haven't done any.
Ditto Pan F.I have, refrigerated for decades, five unused rolls of this film loaded in black plastic canisters in the late 1970s. As I've always disliked the high contrast and soot-whitewash tones of this film, I'll not be using it, but so far no-one I've offered it to has been interested in using it up. One of these days I'll use it to shoot set up portraits of our sleeping cats at home as the subjects befit the by now probably very slow speed of this film. Que sera, sera, as that blond dame in the 1950s movies once sang.
So you never know. Like Steve M. said, why not giving it a try and see? You have little to lose except a small amount of chemicals, a little time, and of course the film.
If interesting results appear, please scan and post. We are waiting.