Sure I went back, finished my undergrad degree, got my masters in Forensic Computing but my 10+ years experience in IT definitely helps.
"We have these weird files, do you know what they are?"
"Oh that's from the same type of document management system this company I worked at uses."
"Oh Lotus Notes, does any one have experience with this?"
"Why yes I do."
Those are some small examples but registry locations, locations of where OS's and Applications keep their files, etc directly translates into useful info in Forensics/Security. We even had someone join my last company as an Associate (sort of entry level) that worked IT for 15yrs, no formal Forensics/Security training, but after a while, he was doing quite well. I think it'd be important to tailor your resume to show you know some of the requisite info and bring it home in an interview.