first let me say, iv had 3 years of fencing experience, and iv been in okinawan gojuryu karate for 6 months (not alot, but iv got a taste and love it!) let me say, that traditional epee fencing (modernized rapier fencing in the USFA) would not work directly with a katana. Now let me say if you could take sabre fencing, which is more like the katana, a slashing weapon, it could some-what easily be utilized with a katana. Finally, if you take enough lessons from fencing, and understand the principles, you could theoretically use most any weapon somewhat skillfully, or use hand-to-hand fighting. fencing teaches you principles which can be related to in other styles of martial arts.