The head and neck squamous cell carcinoma (HNSCC) transcriptome has been profiled extensively, nevertheless, identifying biomarkers that are clinically relevant and thereby with translational benefit, has been a major challenge. The objective of this study was to use a meta-analysis based approach to catalog candidate biomarkers with high potential for clinical application in HNSCC. Data from publically available microarray series (N = 20) profiled using Agilent (4X44K G4112F) and Affymetrix (HGU133A, U133A_2, U133Plus 2) platforms was downloaded and analyzed in a platform/chip-specific manner (GeneSpring software v12.5, Agilent, USA). Principal Component Analysis (PCA) and clustering analysis was carried out iteratively for segregating outliers; 140 normal and 277 tumor samples from 15 series were included in the final analysis. The analyses identified 181 differentially expressed, concordant and statistically significant genes; STRING analysis revealed interactions between 122 of them, with two major gene clusters connected by multiple nodes (MYC, FOS and HSPA4). Validation in the HNSCC-specific database (N = 528) in The Cancer Genome Atlas (TCGA) identified a panel (ECT2, ANO1, TP63, FADD, EXT1, NCBP2) that was altered in 30% of the samples. Validation in treatment naïve (Group I; N = 12) and post treatment (Group II; N = 12) patients identified 8 genes significantly associated with the disease (Area under curve>0.6). Correlation with recurrence/re-recurrence showed ANO1 had highest efficacy (sensitivity: 0.8, specificity: 0.6) to predict failure in Group I. UBE2V2, PLAC8, FADD and TTK showed high sensitivity (1.00) in Group I while UBE2V2 and CRYM were highly sensitive (>0.8) in predicting re-recurrence in Group II. Further, TCGA analysis showed that ANO1 and FADD, located at 11q13, were co-expressed at transcript level and significantly associated with overall and disease-free survival (p<0.05). The meta-analysis approach adopted in this study has identified candidate markers correlated with disease outcome in HNSCC; further validation in a larger cohort of patients will establish their clinical relevance.

Introduction: Field cancerization, the occurrence of transformed cells in the area adjacent to the tumor, has been attributed to the probable reasons of local recurrence of oral squamous cell carcinoma. Cancer stem cells (CSCs) have properties of tumor initiation, migration, and metastasis. The objective of the study was to evaluate their role in field cancerization. Experimental Procedure: A panel of CSCs and its related markers was established from literature and validated in i) samples from surgical margins, ii) samples from 1 cm and 2 cm distance from margin around the tumor and in additional sides. First-phase validation was done in retrospective surgical margins of tumor (N=23) by qPCR and immunohistochemistry. The best marker subset from qPCR to predict recurrence was identified by ROC curve and logistic regression analysis and validated by immunohistochemistry. The final validation is being carried out in prospective samples from tumor-adjacent normal area as mentioned above. The marker profiles were correlated with the histology of the samples and the clinical outcome of the patients on follow-up. Summary of Data: Out of 18 markers selected from literature CD44, CD147, SOX2, Snail, ATR, CyclinD1, MMP9 were selected from gene expression of first-phase validation. Among these SOX2, ATR, Cyclin D1, CD44 and CD147 were selected from IHC of first phase for second-phase validation in prospective samples (n=10) collected from 27 patients, which were clinically normal with varied grades of dysplasia; these samples were evaluated by the selected markers from the first set of validation. The correlation of markers expression with disease outcome of patients and with other clinical parameters is currently ongoing. Conclusion: Our results suggest that CSCs have role in field cancerization and might be predictive of tumor recurrence/reinitiation and/or development of second primary tumor. Citation Format: Simple Mohanta, Ravindra DR, Vikram Kekatpure, Naveen Hedne, Vijay Pillai, Shubhra Chauhan, Naveen BS, Athira Ramakrishnan, Bichu Jacob, Vishak Surendra, Leeky Mohanty, Anjana Muralidharan, Amritha Suresh, Moni Abraham Kuriakose. Cancer stem cells in field cancerization of oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3070.