Catherine:  Your idea that the supernumerary breast tissue may be at
higher risk of breast cancer as an unsuckled breast is a good one.  I
don't know if there are any data on this, and it's doubtful since studies
I've seen on breast cancer didn't mention location of the tumor.  Also,
even if they did, the supernumerary breasts are probably not common
enough to be picked up in the statistical studies.  However, when I teach
breast self-examination, I've always made it a point that they should
examine up into the armpit (long before I knew about
supernumerary breasts), since there is usually an "axillary tail" of the
breast (that's the anatomical term that describes the way the normal
breast extends into the armpit).  Alicia.  [log in to unmask]