title: Female sex and long-term survival post curative resection for non-small-cell lung cancer.
abstract: OBJECTIVE
  To determine whether patient sex has a significant effect on long-term outcomes post curative resection of non-small-cell lung cancer.
  
  
  METHODS
  We retrospectively analysed a prospectively validated thoracic surgery database (n = 4212), from a single institution, from September 2001 to October 2012. Univariate, Cox multivariate and propensity analysis was performed. Long-term follow-up was carried out via the National Strategic Tracing Service that operates in the United Kingdom.
  
  
  RESULTS
  One hundred per cent follow-up was achieved. Overall institutional in-hospital mortality was 2.0% for all thoracic resections. Median survival was 2.78 years (range 0-13 years). Two thousand two hundred and thirty-three males and 1979 females were included. Kaplan-Meier survival of all the patients demonstrated superior survival of females for all stages, P = 0.0003, and stage I, P = 0.0006. Female sex conferred no survival advantage in stage II, P = 0.7, and IIIa, P = 0.1. Sub-analysis by histological type demonstrated that females had superior survival with adenocarcinoma compared with males, P < 0.001, but no sex difference existed with squamous carcinomas, P = 0.2. Cox analyses demonstrated that female sex was an advantageous prognostic factor for the entire study group [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.69-0.96] and Stage I only (HR 0.70, 95% CI 0.57-0.63). Sex was of no significance in Stage II and IIIa disease with regard to survival. Sub-analysis demonstrated that female sex was not a significant factor determining survival in patients with squamous carcinoma; however, it was significantly associated with increased survival in patients with adenocarcinoma (HR 0.63, 95% CI 0.51-0.78). A 1:1 propensity analysis confirmed the above findings.
  
  
  CONCLUSIONS
  Propensity matching and Cox multivariate regression analysis confirmed the univariate finding that female sex is only associated with improved survival in patients with Stage I adenocarcinoma. Patient sex does not affect survival of patients with squamous carcinoma.
authors.affiliation: Liverpool Heart and Chest Hospital, Liverpool, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Warwick
authors.forename: Michael
authors.initials: M
authors.lastname: Shackcloth
authors.forename: Neeraj
authors.initials: N
authors.lastname: Mediratta
authors.forename: Richard
authors.initials: R
authors.lastname: Page
authors.forename: James
authors.initials: J
authors.lastname: McShane
authors.forename: Mathew
authors.initials: M
authors.lastname: Shaw
authors.forename: Michael
authors.initials: M
authors.lastname: Poullis
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000601:surgery*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000401:mortality* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy; D012189:Retrospective Studies; D012737:Sex Factors; D006113:United Kingdom / Q000453:epidemiology
keywords: Female; Lung cancer; Survival