Sure, it's a neat photoshopping trick since the models actually still have their mammaries - but the scars are real in that it's the scars from Andrea Martin, director of The Breast Cancer Fund who's had mastectomies a few years ago.
The campaign for Breast Cancer awareness was created by Ken Mendelbaum at BBDO West and photographed by Heward Jue.



Links:
[1] http://technorati.com/tag/press & poster ads
[2] http://technorati.com/tag/sway (pro-bono / non-profit ads)