Breastfeeding was associated
with a 4-fold increased risk only for breast cancer that overexpressed
HER-2
/neu in this particular article:
http://cebp.aacrjournals.org/cgi/content/full/9/1/65
Also, prolactin protects bc cells against apoptosis or cell death:
http://www.nature.com/bjc/journal/v91/n2/abs/6601947a.htm
Also, oxytocin has a antiproliferative effect on bc cells through the PKA pathway, which inhibits Ras and proliferation:
http://www.ncbi.nlm.nih.gov/sites/en...&dopt=Abstract
PS I breastfeed about a year before I got bc. Interesting.