Both AudioQuest and Acoustic Revive make dedicated LANcables for audio use. Acoustic Revive also makes a special filter for use with LAN cables. I once read a review about these cables and filters on the Polish website highfidelity.pl - which also has an English translation for all of its articles.
But I have never used these cables or filters myself, though I am really interested if they work, and how.

MD600, MS600