Immunohistochemical detection of estrogen and progesterone receptors in primary breast cancer

To evaluate the reliability of the immunohistochemical assay for estrogen receptor (ER) and progesterone receptor (PR) in the prognosis of patients with breast cancer, 83 primary tumors from the patients were studied. Immunohistochemical analysis was performed using antibody ER 1D5 for ER determination and antibody PR-ICA for PR determination. Of all tumors, ER and PR positivities were detected in 36.1% and 45.8% respectively. There was no significant relationship between ER, PR and age of the patients, tumor size or number of involved nodes. However, we found that only the immunohistochemical ER was a predictor of early recurrence in patients with primary breast cancer. In addition, there was no additive effect in recurrence-free survival when both receptor expressions were combined.