title: Significance of EpCAM and TROP2 expression in non-small cell lung cancer.
abstract: BACKGROUND
  The tumor-associated calcium signal transducer (TACSTD) genes, originally designated epithelial cell adhesion molecule (EpCAM) and TROP2, represent true oncogenes. Little is known about EpCAM and TROP2 gene expression in non-small cell lung carcinoma (NSCLC). This study evaluated EpCAM and TROP2 protein expression and clinicopathologic significance in cases of NSCLC.
  
  
  METHODS
  Tissue microarray blocks acquired from 164 cases of NSCLC, including 100 cases of adenocarcinoma (AdC) and 64 of squamous cell carcinoma (SCC), were examined by immunohistochemical staining for EpCAM, and TROP2. The results were correlated with clinicopathologic data.
  
  
  RESULTS
  EpCAM and TROP2 were significantly overexpressed in SCC than in AdC (P < 0.01). In AdC, EpCAM overexpression was closely related to sex, histologic grade, pathologic T stage, pathologic N stage, and TNM stage, and TROP2 overexpression was only related to histologic grade (P < 0.05, respectively). In SCC, correlations were evident between EpCAM overexpression and TNM stage (P = 0.01), and between TROP2 overexpression and pathologic T stage (P = 0.02). EpCAM overexpression showed no significance with overall survival in AdC and SCC patients. However, TROP2 overexpression in AdC had a positive influence on overall survival (P = 0.02) and disease-free survival (P = 0.03). In particular, AdC patients with stage II or III showed better overall survival (P = 0.05) and disease-free survival (P = 0.04).
  
  
  CONCLUSIONS
  While EpCAM and TROP2 show weak and non-complete membranous staining in normal bronchial epithelium and pneumocyte, their complete membranous expression in carcinoma suggests their role in carcinogenesis. EpCAM and TROP2 were more frequently overexpressed in SCC. EpCAM overexpression had no prognostic value in this study, but TROP2 overexpression showed better survival in AdC patients and might be a better prognostic marker in advanced stage AdC.
authors.affiliation: Department of Pathology, School of Medicine, Pusan National University, Beomeo-ri, Mulgeum-eup, Yangsan 626-770, South Korea.
authors.forename: Min Gyoung
authors.initials: MG
authors.lastname: Pak
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Shin
authors.forename: Chang Hun
authors.initials: CH
authors.lastname: Lee
authors.forename: Min Ki
authors.initials: MK
authors.lastname: Lee
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D014408:Biomarkers, Tumor; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D016009:Chi-Square Distribution; D000071858:Epithelial Cell Adhesion Molecule; D005260:Female; D015870:Gene Expression; D006305:Health Status Indicators; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D056910:Republic of Korea; D015398:Signal Transduction; D013223:Statistics as Topic
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; D000071858:Epithelial Cell Adhesion Molecule; C499380:TACSTD2 protein, human