I do not recal having seen a retinic acid. I searched NCBI adh there was only ony referecne which looked like it might be a spelling error.
There is a retinoic acid which does relate according to the trials to breast cancer.
http://www.ncbi.nlm.nih.gov/entrez/q...arch&DB=pubmed
It also from memory features heavily in the PPAR fat pathways in the liver and is involved in the omega three and six pathways.
http://www.ncbi.nlm.nih.gov/entrez/q...arch&DB=pubmed
Retinoic acid is in the same basket as retinoids vitiman a etc, and has a relation to dietary intake, and can act as hormones (as can fats).
It is a subject I have not read much about and only seen bits in passing - more reading when I get time - but all leading back to diet - folates from green things also feature in the functioning of the PPAR pathways.
Hence my constant comments as to the complexity of it all, and diet having to be a good starting place.
http://lpi.oregonstate.edu/infocente...mins/vitaminA/
http://66.102.9.104/search?q=cache:l...ient=firefox-a
I hope that helps. Sorry I cannot be more specific.
RB