title: Performance status and smoking status are independent favorable prognostic factors for survival in non-small cell lung cancer: a comprehensive analysis of 26,957 patients with NSCLC.
abstract: BACKGROUND
  Performance status (PS) is an important factor in determining survival outcome in non-small cell lung cancer (NSCLC) but is generally confounded by stage, age, gender, and smoking status. We investigated the prognostic significance of PS taking into account these important factors.
  
  
  METHODS
  Retrospective analysis of registry database of the National Hospital Study Group for Lung Cancer (NHSGLC) between 1990 and 2005. Univariate analysis was performed using Kaplan-Meier method. Multivariate analysis was performed using Cox proportional hazards model to identify independent prognostic factors.
  
  
  RESULTS
  A total of 26,957 patients with NSCLC were analyzed of which 12,613 patients (46.8%) had World Health Organization (WHO) PS = 0, 8,137 patients were never smokers (30.2%), and most of them were females (72.7%). The majority of PS = 0 patients presented with stage I disease (56.9%). Patients with PS = 0 constituted the group with the highest proportion of never smokers (36.7%). There was a significant difference in the median overall survival (OS) between patients with PS = 0 and PS = 1 (51.5 months versus 15.4 months, respectively; p < 0.0001) and among patients with various PS within individual American Joint Committee on Cancer stage (all p values <0.0001). Never smokers had significantly improved median OS than ever smokers (30.0 months versus 19.0 months, respectively; p < 0.0001). Multivariate analysis demonstrated good PS, never smoker (versus ever smoker; hazard ratio = 0.935, 95% confidence interval: 0.884-0.990; p = 0.0205), early stage, female gender, squamous cell carcinoma histology, and treatment were all as independent favorable prognostic factors.
  
  
  CONCLUSIONS
  PS and smoking status are independent prognostic factors for OS in NSCLC.
authors.affiliation: National Hospital Organization (NHO) Kinki-Chuo Chest Medical Center, Sakai, Osaka, Japan. t-kawaguchi@kch@hosp.go.jp
authors.forename: Tomoya
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Minoru
authors.initials: M
authors.lastname: Takada
authors.forename: Akihito
authors.initials: A
authors.lastname: Kubo
authors.forename: Akihide
authors.initials: A
authors.lastname: Matsumura
authors.forename: Shimao
authors.initials: S
authors.lastname: Fukai
authors.forename: Atsuhisa
authors.initials: A
authors.lastname: Tamura
authors.forename: Ryusei
authors.initials: R
authors.lastname: Saito
authors.forename: Yosihito
authors.initials: Y
authors.lastname: Maruyama
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kawahara
authors.forename: Sai-Hong
authors.initials: SH
authors.lastname: Ignatius Ou
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018287:Carcinoma, Large Cell / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012907:Smoking / Q000401:mortality*; D055815:Young Adult