Comparison of osteopontin, beta-catenin and hnRNP B1 expression in lung carcinomas.

This study was performed to compare osteopontin (OPN), beta-catenin and heterogeneous nuclear ribonucleoprotein B1 (hnRNP B1) immunreactivities in small cell lung carcinomas (SCLC) and non-small cell lung carcinomas (NSCLC). Correlation of these three antibodies with grade and clinicopathologic stage of the tumor in NSCLC was also investigated. Twenty-nine SCLC, 6 large cell carcinoma, 36 adenocarcinoma and 30 squamous cell carcinoma (SCC), totally 101 cases, were included in this study. OPN, beta-catenin and hnRNP B1 expressions were immunohistochemically evaluated. OPN positivity was 6.9% in SCLC and 67% in NSCLC. When NSCLC types were individually considered, OPN positivity was 66.7% in large cell carcinoma, 80% in SCC and 55.6% in adenocarcinomas. beta-catenin positivity was observed in 48.6% of NSCLC and none of SCLC cases. These results were statistically significant (p < 0.05). Neither grade nor stage of NSCLC was correlated with osteopontin, beta-catenin or hnRNP B1 immunreactivity. We observed that OPN and beta-catenin are useful in differentiating SCLC from NSCLC. This may be helpful in small lung biopsies where morphology is obscured by crush artifacts.