any lease can be broken........
the question you really want to know is..how much will it cost you...right?
Well read your lease......basically you are liable for the landlords damage, not only the apartment damage but if he loses rent due to not being able to re-rent it asap!
But he has to try and re rent it at the same rent you are paying, it is illegal for the landlord to jack up the rent 25% and then come sue you months later and for the back rent.
It would be nice to show the apartment to prospective tenants then the landlord would look BAD in front of a judge if you have to sue him in small claims court to get your security back.
And MOST IMPORTANTLY.....when you make a move out date, YOU MUST KEEP IT.......it doesnt matter if you have NOT closed on your house you will have to live in a motel IF the landlord had already re-rented the place. IF you dont move you could be liable for all the NEW TENANTS damages too!
So to prevent that, aim for a closing at the beginning of the month, BUT pay rent for the full month, just in case...oh and dont expect any of it back.