Prevalence of gene amplifications of SOX-2, c-MET, and FGFR1 in Asian patients with esophageal squamous cell carcinoma.

Abstract

e15127 Background: Amplifications of SOX-2, c-MET, and FGFR1 have recently been recognized as important molecular derangements with therapeutic implication in squamous cell carcinoma of lung. We investigated the significance of these molecular derangements in esophageal squamous cell carcinoma (ESCC). Methods: Locally advanced ESCC patients who had received curative- intent loco-regional therapy and had available pre-treatment endoscopic biopsy tissues at National Taiwan University Hospital, Taipei, Taiwan, were enrolled. DNA was extracted from formalin-fixed paraffin-embedded tissues. Amplifications of SOX-2, c-MET, and FGFR1 were evaluated by quantitative PCR (TaqMan Copy Number Assay, Applied Biosystems, CA, USA), using TERT as a reference gene. Amplification of specific gene was defined as a copy number more than 4. Results: Forty locally advanced ESCC patients, M: F= 39: 1 with a median age of 56 years (range: 37 to 80), were included. The primary tumors located at cervical, upper thoracic, middle thoracic, and lower thoracic esophagus in 2, 9, 23, and 6 patients, respectively; the tumor staging according to AJCC 2002 version was T3N0, AnyTN1, and M1a in 1, 37, and 2 patients, respectively. Amplifications of SOX-2 and c-MET were identified in 14 (35%) and 7 (17.5%) patients, respectively. No FGFR1 amplification was detected. The amplifications of SOX-2 and c-MET were not associated with any known clinical features of the patients, including gender, age (<60 vs ≧60), primary tumor location, clinical stage, and performance status (ECOG 0, 1). Conclusions: Amplifications of SOX-2 and c-MET, existing in significant portions of Asian patients with ESCC, are worthy of exploration as therapeutic targets of ESCC.