Oxandralone can help the liver recover from harsh cycles... unlike other orals, oxandralone doesn't cause liver damage, but is actually used to treat it.
Long cycles above 25mg/day should be avoided. I don't recomend year long cycles, but if you must, I'd say stay at 15mg per day. This may actually help to increase fat burning in the abdominal area, but not so much bodyfat in general. As far as muscle growth, you shouldn't expect much difference.
-Stew