PI3K expression predicts overall survival in lung adenocarcinoma.

BACKGROUND: Phosphoinositide 3-kinase (PI3K)/phosphorylated PI3K (p-PI3K) is considered a hallmark in tumor initiation and progression, but its prognostic value in non-small cell lung cancer (NSCLC) remains controversial. METHODS: In the present study, we included 118 NSCLC tissue samples and 13 adjacent normal lung tissue specimens. Immunohistochemical staining was applied to test PI3K/p-PI3K expression. Pearson Chi-squared test and Kaplan-Meier curve were conducted to analyze its correlation with both clinicopathological features and prognosis in NSCLC patients. RESULTS: PI3K/p-PI3K expression in lung cancer tissue differed significantly from that of normal lung tissue (P < 0.001). M stage was significantly correlated to PI3K expression (P = 0.037), but no significant association was found between p-PI3K expression and clinical characteristics. Neither PI3K nor p-PI3K were correlated to overall survival of NSCLC patients (P = 0.105 and P = 0.190, respectively). However, it was found in subgroup analysis that lung adenocarcinoma patients with positive PI3K expression had a favorable survival (P = 0.043). Notably, this correlation was determined invalid in subsequent multivariate analysis (P = 0.052). CONCLUSIONS: PI3K could predict the overall survival of lung adenocarcinoma patients, but failed to be an independent prognostic predictor.