Evaluation of the pattern of SOX2 expression in non-small cell lung cancer (NSCLC) and correlation with clinicopathologic (CP) features and prognosis.

Abstract

e21106 Background: SOX2 is an embryonic stem cell transcription factor that plays a crucial role in differentiation and maintaining pluripotency. We examine the pattern of SOX2 expression and assess correlation with CP features in NSCLC. Methods: Using the AQUA method of automated quantitative immunofluorescence we measured SOX2 expression in two cohorts (in a tissue microarray format), from Yale New Haven Hospital (YTMA 79) and an independent cohort from Patras University Hospital in Greece (YTMA 140) (196 and 342 cases, respectively). YTMA 140 had high percentage of Squamous cell carcinoma (SCC) (48.8%) as opposed to 17.9% in YTMA 79. There were more stage III & IV pts in YTMA 140 (41.3%) compared to YTMA79 (30.6%). 88% of pts in the YTMA 140 were male compared to 52.5% in YTMA79. Survival analysis was done using Kaplan-Meier analysis with log-rank test. The associations between SOX2 expression level and CP features were evaluated by using non-parametric Kruskal-Wallis test. Results: In both cohorts, we found significantly higher SOX2 expression in SCC compared to adenocarcinoma. There was no correlation with gender or stage. Using the threshold of specific signal detection as the cut point, we divided the cohorts into expressers and non-expressers. YTMA 140 cohort which is enriched in SCC showed that 28/161(17.3%) pts with SCC were SOX2 non-expressers. Pts who were SOX2 non-expressers had a worse median overall survival (15 months) compared to pts who were SOX2 expressers (23.5 months) (p=0.015). Conclusions: Our data reveals that pts who have SCC have significantly higher expression of SOX2 and higher SOX2 expression correlates with better outcome. Further studies to define the molecular characteristics of SCC may elucidate more effective markers and effective classification for NSCLC.