title: Prognostic value of chronic obstructive pulmonary disease in 2994 cases of lung cancer.
abstract: OBJECTIVE
  Given the frequent association between chronic obstructive pulmonary disease (COPD) and lung cancer (LC), the objective of this paper is to analyse the prognosis of this comorbidity.
  
  
  METHODS
  Multicenter prospective study compiling 2994 consecutive cases of surgically treated LC (1993-1997), the population with non-small cell lung cancer and complete resection was selected for the prognostic study of COPD. COPD is defined when the FEV1/FVC is <0.7 (n=1370; 46%). Overall and conditional survivals (survival likelihood when alive at 2, 3 or 5 years after treatment) as well as the degree of severity (FEV1% percentiles) were calculated to establish prognosis.
  
  
  RESULTS
  Although the overall survival is similar whether or not COPD is present (Log-rank: 0.34), the conditional survival analysis is different in every stage at 60 months (Log-rank: 0.02) and different in stage pI at 24-36 months (Log-rank: 0.04). In LC (stage pI) with COPD, the presence of a worst pulmonary function (last FEV1% percentile vs first FEV1% percentile) is a bad prognostic factor (Log-rank: 0.002).
  
  
  CONCLUSIONS
  The analysis of conditional survival at 24 months shows that COPD can be considered as a prognostic factor and that there is a clear relationship between the severity of the condition (FEV1%) and survival.
authors.affiliation: Pneumology Service, Hospital Universitario 12 de Octubre, Crrta. Andalucia 5.4, 28041 Madrid, Spain. lencuent@h12o.es
authors.forename: Angel
authors.initials: A
authors.lastname: López-Encuentra
authors.forename: Julio
authors.initials: J
authors.lastname: Astudillo
authors.forename: Jorge
authors.initials: J
authors.lastname: Cerezal
authors.forename: Federico
authors.initials: F
authors.lastname: Gonzalez-Aragoneses
authors.forename: Nuria
authors.initials: N
authors.lastname: Novoa
authors.forename: Abel
authors.initials: A
authors.lastname: Sánchez-Palencia
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications* / Q000401:mortality / Q000601:surgery; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications* / Q000401:mortality / Q000601:surgery; D008297:Male; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D016019:Survival Analysis; D013908:Thoracotomy