Immunohistochemical Expression of Estrogen and Progesterone Receptors Identifies a Subset of NSCLCs and Correlates with EGFR Mutation

Purpose: To determine the frequency of estrogen receptor α and β and progesterone receptor protein immunohistochemical expression in a large set of non–small cell lung carcinoma (NSCLC) specimens and to compare our results with those for some of the same antibodies that have provided inconsistent results in previously published reports. Experimental Design: Using multiple antibodies, we investigated the immunohistochemical expression of estrogen receptors α and β and progesterone receptor in 317 NSCLCs placed in tissue microarrays and correlated their expression with patients9 clinicopathologic characteristics and in adenocarcinomas with EGFR mutation status. Results: Estrogen receptors α and β were detected in the nucleus and cytoplasm of NSCLC cells; however, the frequency of expression (nucleus, 5-36% for α and 42-56% for β; cytoplasm: P = 0.0048 to P = 0.015) in multivariate analysis. In adenocarcinomas, estrogen receptor α expression correlated with EGFR mutation ( P = 0.0029 to Conclusions: Estrogen receptor α and β expression distinguishes a subset of NSCLC that has defined clinicopathologic and genetic features. In lung adenocarcinoma, estrogen receptor α expression correlates with EGFR mutations. (Clin Cancer Res 2009;15(17):5359–68)