title: Prognostic significance of claudin 4 in completely resected adenocarcinoma of the lung.
abstract: BACKGROUND
  The development of diagnostic techniques and an awareness of health examinations can bring about an early diagnosis of lung cancer. However, appropriate postoperative management and adjuvant chemotherapy remain under debate in postoperative therapeutic strategy. The present study was conducted to assess the clinicopathologic factors that influence recurrence and prognosis after complete resection of lung cancer.
  
  
  METHODS
  The present study analyzed 62 patients with lung cancer who underwent complete resection of diagnosed adenocarcinoma between 1994 and 2007. In addition to conventional factors, which include staging factor and histological evaluation, the present study also performed univariate and multivariate analyses to consider claudin, a cell adhesion molecule, as a prognostic factor by immunohistochemical staining.
  
  
  RESULTS
  There was no correlation between conventional factors, including lymphatic and vascular invasion, and recurrence. However, there was a significant correlation between high expression of claudin 4 and cancer recurrence. In particular, there was a correlation between high expressions of claudin 1, 4, and 5 and a reduction of disease-free survival.
  
  
  CONCLUSIONS
  Increased expressions of claudin 4 were negative prognostic factors in adenocarcinoma of the lung and thus could be used to identify high-risk patients for adjuvant chemotherapy, even if they had early-stage lung cancer. The present findings collectively suggest that consideration of claudin as a prognostic factor in the active postoperative treatment in patients at high risk will lead to better therapeutic outcomes with fewer side effects.
authors.affiliation: Departments of Thoracic and Cardiovascular Surgery, Keimyung University Dongsan Medical Center, Korea.
authors.forename: Min Cheol
authors.initials: MC
authors.lastname: Chae
authors.affiliation: Departments of Thoracic and Cardiovascular Surgery, Keimyung University Dongsan Medical Center, Korea.
authors.forename: Chang Kwon
authors.initials: CK
authors.lastname: Park
authors.affiliation: Departments of Thoracic and Cardiovascular Surgery, Keimyung University Dongsan Medical Center, Korea.
authors.forename: Dong Yoon
authors.initials: DY
authors.lastname: Keum
authors.affiliation: Departments of Pathology, Keimyung University Dongsan Medical Center, Korea.
authors.forename: Ilseon
authors.initials: I
authors.lastname: Hwang
authors.affiliation: Departments of Pathology, Keimyung University Dongsan Medical Center, Korea.
authors.forename: Kun Young
authors.initials: KY
authors.lastname: Kwon
authors.affiliation: Department of Medical Genetic Engineering, Keimyung University School of Medicine, Korea.
authors.forename: Byeong Churl
authors.initials: BC
authors.lastname: Jang
keywords: 1. Lung neoplasms; 2. Adenocarcinoma; 3. Discard; 4. Lung pathology; 5. Claudin