title: A robust prognostic gene expression signature for early stage lung adenocarcinoma.
abstract: BACKGROUND
  Stage I lung adenocarcinoma is usually not treated with adjuvant chemotherapy; however, around half of these patients do not survive 5 years. Therefore, a reliable prognostic biomarker for early stage patients would be critical to identify those most likely to benefit from early additional treatments. Several studies have searched for gene expression prognostic biomarkers for lung adenocarcinoma, but these have not yielded a widely accepted prognosticator.
  
  
  RESULTS
  We analyzed gene expression from seven published lung adenocarcinoma cohorts for which we included only stage I and II patients who were not given adjuvant therapy. Seven genes consistently obtained statistical significance in Cox regression for overall survival. The combined signature has a weighted mean hazard ratio of 3.2 in all cohorts and 3.0 (C.I. 1.3-7.4, p < 0.01) in an independent validation cohort and is strongly correlated with previously published signatures of chromosomal instability and cell cycle progression.
  
  
  CONCLUSIONS
  The new prognostic signature, if validated prospectively, may enable better stratification and treatment of early stage lung cancer patients.
authors.affiliation: Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, Lyngby, Denmark.
authors.forename: Marcin
authors.initials: M
authors.lastname: Krzystanek
authors.affiliation: Department of Tumor Biology, National Koranyi Institute - Semmelweis University, Budapest, Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Moldvay
authors.affiliation: Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.
authors.forename: David
authors.initials: D
authors.lastname: Szüts
authors.affiliation: Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, Lyngby, Denmark ; Computational Health Informatics Program (CHIP), Boston Children's Hospital, Boston, USA ; Harvard Medical School, Boston, USA.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Szallasi
authors.affiliation: Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, Lyngby, Denmark.
authors.forename: Aron Charles
authors.initials: AC
authors.lastname: Eklund
keywords: Early stage cancer; Gene expression; Lung adenocarcinoma; Prognostic biomarker