I would look further than just an upgraded network cable, in my experience an "audiophile" network switch brings more improvement.
My set up consists of 12 meter (certified) Bleu Jeans Cat6A from my Router/NAS to my stereo rig, then an AQvox network switch, with two AQ Vodka's connected to Aurender and dCs Rossini.
Thanks for the comments. My home and network are 1 year old; no need to make any changes at this point.