title: Reduction of Serum Cytokeratin-3A9 is Associated with Chemotherapeutic Response in Patients with Non-Small Cell Lung Cancer.
abstract: BACKGROUND
  Many tumor markers have been analyzed for applications in diagnosis, prognosis, and monitoring of cancer. Currently chemotherapy is routinely performed for patients with non-small cell lung cancer (NSCLC). The purpose of this study was to examine the serum tumor biomarker of cytokeratin (CK)-3A9 level in patients with NSCLC and its potential correlation with chemotherapeutic response.
  
  
  METHODS
  The serum samples of 196 NSCLC patients, 84 healthy controls, and 87 benign lung disease patients were provided for measurement of CK-3A9 and carcinoembryonic antigen (CEA). Serum CK-3A9 concentration was examined using a chemoluminescent method. The potential correlation between serum CK18-3A9 concentration and chemotherapeutic response was analyzed in 124 patients with advanced NSCLC (stages III and IV).
  
  
  RESULTS
  The serum CK-3A9 levels in NSCLC patients pre-chemotherapy were significantly higher than those of healthy controls and benign lung disease patients (p < 0.01). CK-3A9 was related to Union for International Cancer Control (UICC) stages (p < 0.01) and histological classification (p < 0.05), but not related to age, gender, smoking status, and chemotherapy regimen (all p > 0.05). The testing results of serum CK-3A9 levels showed a higher sensitivity than that for CEA (48.2% and 39.5%, respectively). The chemotherapeutic response in the 124 patients with advanced NSCLC included 0 complete response (CR), 50 partial response (PR), 65 no change (NC), and 9 progression disease (PD). Post-chemotherapy CK-3A9 levels were significantly decreased compared to pre-chemotherapy (p < 0.05). The serum CK-3A9 levels in patients who achieved PR declined significantly compared to those who did not respond (SD + PD) after 2 cycles chemotherapy (p < 0.05).
  
  
  CONCLUSIONS
  CK-3A9 appeared to be a new biomarker for reliable, cost-effective prediction of the efficacy of chemotherapy in patients with advanced NSCLC, although the results should be confirmed in larger studies.
authors.forename: Guang-Li
authors.initials: GL
authors.lastname: Shi
authors.forename: En-Dong
authors.initials: ED
authors.lastname: Wu
authors.forename: Yong
authors.initials: Y
authors.lastname: Sun
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Yin
authors.forename: Chang-Xing
authors.initials: CX
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000188:drug therapy*; D016022:Case-Control Studies; D002945:Cisplatin / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007633:Keratins / Q000097:blood*; D008175:Lung Neoplasms / Q000097:blood / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged
chemical_list: D000970:Antineoplastic Agents; D015415:Biomarkers; D007633:Keratins; D002945:Cisplatin