I don't use internet explorer myself, and without knowing what kind of proxy your network is using I can only give the vaguest of answers, but here goes:
If your network contains a proxy and your browser is configured to use said proxy for https traffic, then anyone with admin access to the machine said proxy is running on can theoretically reconfigure the proxy to provide them with a copy of any traffic going through it.
Furthermore, if your connection to the proxy is unencrypted, then anyone with admin access to the network hardware (switches, routers) can use packet capture software like WireShark to intercept and read your traffic.
Finally, if someone who isn't you has admin access to your computer, or if your computer and/or browser have been compromised by malware, they might in theory be able to read your browser cache and reconstruct your document from it.
TL;DR You haven't given us nearly enough information to answer your question in anything but the broadest of terms. The answer is "theoretically, yes", but the vagueness of the question renders it as useless as the same answer would be if I were to ask "If I cross the street, could I get hit by a car?" -- it's certainly possible but without context there's no way to estimate likelihood.