This is the email my derm. sent back to me. I'm going to send her the links listed in the potty training thread and see what she has to say.

Parabens is a preservative. It is in most moisturizing creams. It is known
to rarely cause a skin sensitivity allergy. I do not know of any
association with cancer associated with this preservative in mosturizers.
If you have seen something please send a link and I will check it out. If
there is a connection to cancer reported, I imagine it would be at a level
of exposure much larger than what is in creams (perhaps the level absorbed
by someone in a factory that produces the chemical would be a problem, for
Mom to Julia