Androgen receptors and serum testosterone levels identify different subsets of postmenopausal breast cancers

Androgen receptors (AR) are frequently expressed in breast cancers, but their implication in cancer growth is still controversial. In the present study, we further investigated the role of the androgen/AR pathway in breast cancer development. AR expression was evaluated by immunochemistry in a cohort of 528 postmenopausal breast cancer patients previously examined for the association of serum testosterone levels with patient and tumor characteristics. AR expression was classified according to the percentage of stained cells: AR-absent (0%) and AR-poorly (1%-30%), AR-moderately (>30%-60%), and AR-highly (>60%) positive. Statistical analysis was performed in 451 patients who experienced natural menopause. AR-high expression was significantly related with low histologic grade and estrogen receptor (ER)- and progesterone receptor (PR)-positive status (P trend