title: Prognostic factors in resected stage I non-small-cell lung cancer: a multivariate analysis of six molecular markers.
abstract: OBJECTIVE
  To analyze the prognostic significance of six molecular biomarkers (death-associated protein kinase [DAPK] promoter methylation, interleukin-10 [IL-10] protein expression, cyclooxygenase-2 [COX-2] mRNA expression, human telomerase reverse transcriptase catalytic subunit [hTERT] mRNA expression, retinoic acid receptor-beta [RAR-beta] mRNA expression, and K-ras mutational status) in stage I non-small-cell lung cancer (NSCLC) patients.
  
  
  METHODS
  Biomarker analyses were performed on tumors from 94 patients with stage I NSCLC who underwent surgical resection at our institution. A minimum follow-up period of 5 years was required. DAPK methylation was assessed by methylation-specific polymerase chain reaction (PCR). RAR-beta, COX-2, and hTERT mRNA levels were determined by in situ hybridization with digoxigenin-labeled antisense riboprobes. K-ras mutation status was determined by the PCR-primer introduced restriction with enrichment for mutant alleles method. IL-10 protein expression was analyzed by immunohistochemistry using a polyclonal antihuman IL-10 antibody. Cancer-specific survival was analyzed with a Cox proportional hazards model. To identify independent prognostic factors, a stepwise selection method was used.
  
  
  RESULTS
  DAPK methylation, IL-10 lack of expression, COX-2 expression, hTERT expression, RAR-beta expression, and K-ras mutations were observed in 46.8%, 29.8%, 59.6%, 34.0%, 23.4%, and 34.0% of patients, respectively. In the final model, DAPK methylation and IL-10 lack of expression were significant negative prognostic factors for cancer-specific survival, whereas COX-2 expression was of borderline significance.
  
  
  CONCLUSIONS
  In this cohort of resected stage I NSCLC patients, molecular markers that independently predict cancer-specific survival have been identified. The prognostic roles of DAPK methylation, IL-10, and other biomarkers in NSCLC merit further investigation.
authors.affiliation: Department of Thoracic/Head and Neck Medical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030-4009, USA. clu@mdanderson.org
authors.forename: Charles
authors.initials: C
authors.lastname: Lu
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Soria
authors.forename: Ximing
authors.initials: X
authors.lastname: Tang
authors.forename: Xiao-Chun
authors.initials: XC
authors.lastname: Xu
authors.forename: Luo
authors.initials: L
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.forename: Reuben
authors.initials: R
authors.lastname: Lotan
authors.forename: Bonnie
authors.initials: B
authors.lastname: Kemp
authors.forename: B Nebiyou
authors.initials: BN
authors.lastname: Bekele
authors.forename: Lei
authors.initials: L
authors.lastname: Feng
authors.forename: Waun K
authors.initials: WK
authors.lastname: Hong
authors.forename: Fadlo R
authors.initials: FR
authors.lastname: Khuri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor