Relationship between PRL levels and steroid receptors in breast cancer

The role of PRL in human breast cancer is still debated. We examined 259 women undergoing surgery for breast cancer (K = 183) and for other diseases (n = 76). In all subjects blood samples were taken for the RIA assay of PRL, during the preanaesthesia. In the breast cancer specimens, estrogen (ER) and progesterone (PGR) receptors were assayed and T.N.M. was evaluated. PRL mean values were assayed and T.N.M. was evaluated. PRL mean values were found to be above the normal range in both groups. PRL values in ER+ and PGR+ were lower than in ER- and PGR-. We also divided the patients into two groups (PRL values greater than 50 or less than 50 ng/ml). The difference between the two groups was significant for ER (p less than 0.005) and PGR (p less than 0.05), using Student's unpaired t-test. Besides this, we observed a significant negative linear correlation between PRL values and receptor values. The finding of this correlation suggests that high PRL values could be associated with unfavourable prognosis in breast cancer.