OPLAH Protein Expression Stratifies the Prognosis of Patients With Squamous Cell Carcinoma of the Esophagus.

BACKGROUND/AIM:Squamous cell carcinoma is one of the major subtypes of esophageal carcinoma, and the 5-year overall survival rate of esophageal squamous cell carcinoma patients who underwent curative treatment remains below 40%. We aimed to detect and validate the prognosticators of esophageal squamous cell carcinoma in patients who underwent radical esophagectomy. MATERIALS AND METHODS:Comprehensive analysis of transcriptome and clinical data from The Cancer Genome Atlas revealed OPLAH as one of the differentially expressed genes between esophageal squamous cell carcinoma tissues and normal esophageal mucosa. OPLAH expression changes were significantly associated with a patient prognosis. OPLAH protein levels were further evaluated by immunohisto-chemistry in esophageal squamous cell carcinoma tissues (n=177) as well as in serum samples (n=54) using ELISA. RESULTS:OPLAH mRNA was significantly overexpressed in esophageal squamous cell carcinoma tissues compared to normal esophageal mucosa, and patients with high OPLAH mRNA expression have a significantly poorer prognosis, according to The Cancer Genome Atlas data. The high staining intensity of OPLAH protein in esophageal squamous cell carcinoma tissue clearly stratified patient prognosis. According to multivariable analysis, high OPLAH protein expression was an independent prognostic factor for survival after surgery. Pre-neoadjuvant chemotherapy serum OPLAH protein concentrations were significantly associated with clinical tumor depth and node positivity and, consequently, with advanced clinical stage. The serum OPLAH protein concentration was significantly decreased by neoadjuvant chemotherapy. CONCLUSION:OPLAH protein expression in cancerous tissue and serum may have clinical utility towards stratifying prognosis of patients with esophageal squamous cell carcinoma.