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.