Relationships of parity with breast cancer risk are complex. Parity is associated with decreased risk of postmenopausal hormone receptor positive breast tumors, but may increase risk for basal-like breast cancers and for early onset tumors. Characterizing parity-related gene expression patterns in normal breast and breast tumor tissues may improve our understanding of the biological mechanisms underlying this complex pattern of risk.
Researchers developed a parity signature by analyzing microRNA microarray data from 130 reduction mammoplasty (RM) subjects (54 nulliparous and 76 parous). This parity signature, together with published parity signatures, was evaluated in gene expression data from 150 paired tumors and adjacent benign breast tissues from the Polish Breast Cancer Study, overall and by tumor estrogen receptor (ER) status. The researchers identified 251 genes significantly…
