Kriegsmann K, et al. Histopathology 2020.
OBJECTIVE: Non-small cell lung cancer (NSCLC) and breast cancer are frequent entities. Estrogen receptor (ER), progesterone receptor (PgR), mammaglobin (MAMG), and GATA binding protein 3 (GATA3) are frequently stained to validate a mammary origin in the appropriate diagnostic setting. However, comprehensive data about the immunohistological expression of these markers in NSCLC is limited. Therefore, we analyzed a large cohort of NSCLC and correlated the staining results with clinicopathological variables.
METHODS: A tissue microarray was stained by ER, PgR, MAMG, human epidermal growth factor receptor 2 (HER2), and GATA3 including 636, 536, 65, 34, and 20 adenocarcinomas (ADC), squamous cell carcinomas (SqCC), large cell carcinomas, pleomorphic carcinomas, and large cell neuroendocrine carcinomas, respectively. HER2 status was determined for immunohistochemical positive cases with chromogenic in-situ hybridization. Markers with a proportion of ≥5% positive cases in ADC and SqCC were considered for survival analysis.
RESULTS: In ADC 62 (10%), 17 (3%), 1 (<1%), 7 (1%), and 49 (8%) cases were positive for ER, PgR, MAMG, HER2, and GATA3, respectively. Among SqCC, 10 (2%), 14 (3%), 2 (<1%), and 109 (20%) patients were positive for ER, PgR, HER2, and GATA3, but none of the samples showed positivity for MAMG. ER-positivity was associated with ADC, female gender, smaller tumor size, and lower clinical stage. None of the markers had an impact on survival.
CONCLUSION: We report on ER, PgR, MAMG, HER2, and GATA3 expression in a large cohort of NSCLC. Interpretation of these markers in the differential diagnostic setting should be based on a multi-marker panel.