I'm not Cathe, but I thought I'd weight in given that she's hard at work finalizing the Hard Core roll-out:
As a general rule it is not possible to selectively lose fat stores (and breast tissue is in the main fatty tissue) in a given body area. A good well-rounded fat loss program that involves cardio work and strength training will reduce fat stores overall, but where those fat stores are lost is entirely genetically determined.
Weight lifting will not affect the fat stores beyond creating more metabolically active muscle mass that can chew up calories. Lifts that involve the pecs might change the general shape of the area but not breast size.
I do have the feeling that for significant breast-size reduction, surgery might have to be contemplated. Hopefully others who have your situation might have some further, perhaps differing, options to surgery.
A-Jock