Loss of PTEN Expression is an Independent Poor Prognostic Factor in Non-small Cell Lung Cancer

Abstract

BACKGROUND Alterations in the phosphatase and tensin homolog (PTEN) are correlated with tumor progression. Downregulation of PTEN is related to drug resistance of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC). The aim of this study was to evaluate the prognostic significance of PTEN in patients with NSCLC and its correlation with EGFR. METHODS Two hundred eighty eight surgically resected NSCLC samples, including 168 adenocarcinomas (ADCs), 99 squamous cell carcinomas (SCCs) and 21 other NSCLCs were analyzed for the PTEN. The results were correlated with other clinicopathological variables including EGFR amplification and mutation. RESULTS Loss of PTEN was detected in 42.4% of NSCLCs, specifically 28.6% of ADCs, 66.7% of SCCs, and 38.1% of others. Loss of PTEN was significantly associated with SCC, smoking, male gender, and higher stage. In a multivariate analysis, loss of PTEN was significantly associated with short progression-free survival (p=0.037). No association between PTEN and EGFR was observed. CONCLUSIONS These results suggest that loss of PTEN results in shorter progression-free survival in patients with NSCLC, and loss of PTEN is more associated with SCC, smoking, male gender, and higher T stage by the 7th tumor, node and metastasis staging system but not EGFR status.