ABSTRACT
<p><b>OBJECTIVE</b>To investigate the correlation of prolactin receptor (PRL-R) expression to estrogen receptor (ER) and progesterone receptor (PR) expressions in primary breast cancer.</p><p><b>METHODS</b>For 130 female patients with breast cancer (median age 46 years), PRL-R expression in the primary tumor was detected by immunohistochemistry, and the correlation between PRL-R and ER/PR expressions was analyzed statistically.</p><p><b>RESULTS</b>PRL-R positivity in the primary tumor was found in 89 of the patients (68.5%), and the positivity rate for PRL-R was positively correlated to ER expression (P<0.05). Further stratification of the patients according to the CerbB-2 status revealed such a correlation only in CerbB-2-positive patients (P<0.05). In the patient cohort, no significant correlation was found in the positivity rate between PRL-R and PR expressions (P>0.05), but in CerbB-2-positive patients, the positivity rate of PRL-R showed a positive correlation to PR expression (P<0.05).</p><p><b>CONCLUSION</b>The positive correlations in positivity rate between the PRL-R and ER/PR expressions are found only in CerbB-2 positive patients with breast cancer, and the expressional status of CerbB-2 affects the correlation between PRL-R and ER/PR expression in breast cancer.</p>