Simple answer. No.

Complex answer. Yes. You'll simply need adapters such as the MX2wire+ at each end to run Ethernet over a single copper pair at around $200 for each end so if you were installing 3 cameras you'd need 6 adapters.

I've said that's the complex solution because the reality is if you need to ask that it's probably beyond your skills to actually install it and rewire the current system. Wiring would also be needed from the current alarm to whether your closest Ethernet feed is.

Those are cool devices, its a shame they are only 30megs though

Anyhow as sbiddle said probably just easier if you have an attic to rewire cat5/cat6 for cameras.