Prevalence and clinical significance of RBM3 immunostaining in non-small cell lung cancers.

INTRODUCTION: Aberrant expression of RNA-binding motif protein 3 (RBM3) has been suggested as a prognostic biomarker in several malignancies. MATERIALS AND METHODS: This study was performed to analyse the prevalence and clinical significance of RBM3 immunostaining in non-small cell lung cancers (NSCLCs). Therefore, we took advantage of our tissue microarray (TMA) containing more than 600 NSCLC specimens. RESULTS: While nuclear RBM3 staining was always high in normal lung tissue, high RBM3 staining was only seen in 77.1% of 467 interpretable non-metastatic NSCLCs. Reduced RBM3 staining was significantly associated with advanced pathological tumor stage (pT) in NSCLCs (p = 0.0031). Subset analysis revealed that the association between reduced RBM3 staining and advanced pT stage was largely driven by the histological subgroup of lung adenocarcinoma (LUACs) (p = 0.0036). In addition, reduced RBM3 expression predicted shortened survival in LUAC patients (p = 0.0225). CONCLUSIONS: In summary, our study shows that loss of RBM3 expression predicts worse clinical outcome in LUAC patients.