4566 Background: Chemoradiotherapy (CRT) is a potential alternative to surgery in patients with squamous cell carcinoma of the esophagus. Complete response (CR) to CRT is essential for a good prognosis and there is a need for a predictive method of CR in CRT. Methods: The pretreatment formalin-fixed, paraffin-embedded endoscopic tumor biopsy material was obtained from 41 patients treated with a definitive concurrent CRT (5-FU/CDDP and 60 Gy) for esophageal cancer (cStage II or III). cDNA was derived from tumor cells of biopsy specimens by the laser capture microdissection and analyzed to determine mRNA expression relative to an internal reference gene (β-actin) using fluorescence-based, real-time reverse transcription PCR. Gene expression levels of thymidylate synthase, thymidine phosphorylase, dihydropyrimidine dehydrogenase, orotate phosphoribosyl transferase (OPRT), metylenetetrahydrofolate reductase, dihydrofolate reductase (DHFR), excision repair cross-complementing gene 1, vascular endothelial growth factor, epidermal growth factor receptor and matrix metalloproteinase 9 (MMP-9) were measured. Results: Median gene expression levels of OPRT and DHFR were significantly higher in CR patients (p=0.0206 and 0.0191, respectively). MMP-9 was significantly lower in CR patients (p=0.0436). When the median values of the gene expression levels were selected as the cutoff values, CR rate was significantly higher in the high OPRT group and high DHFR group (p=0.0104 and 0.0104, respectively). However, there was no statistical difference in CR rate between the low MMP-9 group and the high MMP-9 group. Multivariate analysis, including clinical stage and biomarkers, revealed that high OPRT gene expression was an independent predictive factor of CR (p=0.0329, relative risk=6.65, 95% confidence interval, 1.17–37.89%). Conclusions: The measurement of OPRT gene expression in tumor biopsies may be a predictive factor of CR to CRT in patients with squamous cell carcinoma of the esophagus. No significant financial relationships to disclose.
Genomic Analysis Defines a Cancer-Specific Gene Expression Signature for Human Squamous Cell Carcinoma and Distinguishes Malignant Hyperproliferation from Benign Hyperplasia
