One of the town Kosice in Slovakia variations name is Kaschau.
On a US World War I document for a not-so-close relative, it says that he was born in "Kaschan, Hungary." The rest of the family came from various towns in what is today northwestern Romania. I would consider the target region to be bounded by a triangle of large places Oradea, Cluj, and Tasnad. I believe this relative also came from this region. I've searched the JG Town Finder and Gazetteer with various search strategies with nothing even remotely close.
The only reference to the town that I can find by googling, other than someone else also claiming to come from Kaschan, is a reference to the "Kaschan-Oberbergar Bahn" supposedly part of a rail network in Austria-Hungary.
Any suggestions? TIA.
Highland Park, NJ USA