IIRC, DMX was originally designed to take advantage of existing XLR cables but they discovered there were inefficiencies with using Audio cable runs to carry lighting signals.
Worth noting, the impedance of an XLR cable should be in the range of 75ohm, whereas DMX cabling shows an impedance in the 110ohm range. Using XLR cabling for DMX Lighting needs may produce inconsistent functionality of the lights you are trying to illuminate and may manifest in flickering and more than noticeable wavering effect in the output bulbs.
Conversely, attempting to use DMX cabling in place of an XLR cable run, will impact the signal being pulled by the amp which may manifest into damage to the amplifier components, not unlike using speaker impedance vastly different from what the amp was designed to utilize.
In a pinch you could use the cable designed for the different technology on the notion that the current performance may be worth the cost of repairing any damages earned due to the mismatch, but in my opinion the long term best practice would be to carry extra cabling of both types to avoid the future potential problems with using components designed for different uses.
