title: Gender-specific survival after surgical resection for early stage non-small cell lung cancer.
abstract: BACKGROUND
  Lung cancer is the leading cause of cancer death worldwide. The incidence and mortality rate of lung cancer in women has increased. Studies have indicated that females with non-small cell lung cancer (NSCLC) have better survival than males. We aimed to examine the impact of gender on 1-, 5- and 10-year survival after surgery for stage I and II NSCLC.
  
  
  METHODS
  During the period 2003-2013, 692 patients operated for stage I and II NSCLC were prospectively registered. Patients were stratified into four groups according to gender and age over or less than 66 years. The relationship between gender and age on overall survival was investigated. Adjustment for multiple confounders was performed using the Cox proportional hazard regression model.
  
  
  RESULTS
  Surgical resection was performed in 368 (53.2%) males and 324 (46.8%) females. During the study period, mortality was 35.2% in younger females, 34.9% in younger males, 42.8% in older females and 51.2% in older males. Stratified by age, there were no significant gender differences with regard to survival [hazard ratio (HR) 1.16, 95% confidence interval (CI) 0.91-1.46, p = .23]. Comparing the younger and the older patients adjusted for confounders, the mortality risk was significantly increased in elderly patients [females, adjusted HR 1.60, 95% CI 1.12-2.28]. Compared with population data, standardized mortality ratio was increased to 4.1 (95% CI 3.5-4.7) in males and to 6.5 (95% CI 5.4-7.6) in females.
  
  
  CONCLUSIONS
  Overall survival did not differ significantly between males and females. Adjusted for confounding factors, we found a significantly increased mortality risk in elder patients compared to their younger counterparts. However, five-year overall survival of more than 50% for older patients with NSCLC should encourage surgical treatment also in elderly lung cancer patients.
authors.affiliation: a Department of Cardiothoracic Surgery, Division of Cardiovascular and Pulmonary Diseases , Oslo University Hospital , Rikshospitalet , Norway.|b Faculty of Medicine , University of Oslo , Norway.
authors.forename: Anders
authors.initials: A
authors.lastname: Bugge
authors.affiliation: b Faculty of Medicine , University of Oslo , Norway.|c Department of Respiratory Medicine, Division of Cardiovascular and Pulmonary Diseases , Oslo University Hospital , Rikshospitalet , Norway.
authors.forename: Johny
authors.initials: J
authors.lastname: Kongerud
authors.affiliation: d Oslo Centre for Biostatistics and Epidemiology , Research Support Services, Oslo University Hospital , Norway.
authors.forename: Cathrine
authors.initials: C
authors.lastname: Brunborg
authors.affiliation: a Department of Cardiothoracic Surgery, Division of Cardiovascular and Pulmonary Diseases , Oslo University Hospital , Rikshospitalet , Norway.|b Faculty of Medicine , University of Oslo , Norway.
authors.forename: Steinar
authors.initials: S
authors.lastname: Solberg
authors.affiliation: b Faculty of Medicine , University of Oslo , Norway.|c Department of Respiratory Medicine, Division of Cardiovascular and Pulmonary Diseases , Oslo University Hospital , Rikshospitalet , Norway.
authors.forename: May Brit
authors.initials: MB
authors.lastname: Lund
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011013:Pneumonectomy; D012737:Sex Factors; D012744:Sex Ratio; D016019:Survival Analysis