XLR leads are generally balanced connections. This means they send the signal twice, once normal and once out of phase. Its a method to reduce noise on the line but the equipment needs to support the technique. Because of this XLR leads have three conductors (ground, signal and negative signal) as opposed to RCA which simply has ground and signal.

You can have them re-terminated but you would be wasting one of the wires inside each leads that you paid for.