title: High expression of cyclooxygenase 2 is an indicator of prognosis for patients with esophageal squamous cell carcinoma after Ivor Lewis esophagectomy.
abstract: BACKGROUND
  The poor prognosis of esophageal squamous cell carcinoma (ESCC) is attributed to a high recurrence rate after surgery. Cyclooxygenase 2 (COX2) is an important regulator of cell growth, differentiation, apoptosis, and transformation. COX2 overexpression is significantly associated with the tumorigenesis and progression of diverse cancers; however, its expression and significance in ESCC remains unclear.
  
  
  METHODS
  We enrolled 118 patients with ESCC who had undergone Ivor-Lewis esophagectomy. The expression profile of COX2 was examined by immunohistochemistry.
  
  
  RESULTS
  A high expression of COX2 correlated with a higher T staging (P = 0.014), lower differentiation degree (P = 0.002), lymph node metastasis (P = 0.009), recurrence status (P = 0.004), and tumor node metastasis (TNM) stage (P = 0.001). Cox regression analysis showed that TNM stage (P = 0.001), differentiation degree (P = 0.001), and high COX2 expression (P = 0.004) were independent risk factors of prognosis.
  
  
  CONCLUSIONS
  Our data indicated that COX2 expression level is associated with key clinicopathological features and could be an effective biomarker to predict ESCC prognosis.
authors.affiliation: Department of Thoracic Surgery Provincial Hospital Affiliated to Shandong University Jinan Shandong China.
authors.forename: Dongxin
authors.initials: D
authors.lastname: Hu
authors.affiliation: Department of Gastroenterology Provincial Hospital Affiliated to Shandong University Jinan Shandong China.
authors.forename: Mingyan
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Thoracic Surgery Provincial Hospital Affiliated to Shandong University Jinan Shandong China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Thoracic Surgery Provincial Hospital Affiliated to Shandong University Jinan Shandong China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Wang
keywords: COX2; Ku80; esophageal squamous cell carcinoma; prognosis; recurrence