title: [Bronchioloalveolar carcinoma in Spain: a rare and different form of lung cancer].
abstract: OBJECTIVE
  To describe a series of cases of bronchioloalveolar carcinoma (BAC) treated surgically between 1993 and 1997 in the 19 hospitals that make up the Bronchogenic Carcinoma Cooperative Group of the Spanish Society of Pulmonology and Thoracic Surgery (GCCB-S).
  
  
  METHODS
  From a total of 2,944 cases of non-small cell lung cancer (NSCLC), 82 (3%) were BAC. The clinical characteristics and prognosis of patients with BAC were compared with those of the remaining 2,862 patients with NSCLC.
  
  
  RESULTS
  The percentage of men was lower for BAC than for other types of NSCLC (64.6% compared with 93.5%; P< .001) and BAC was associated with less comorbidity (50% vs 62%; P< .05), particularly in terms of chronic obstructive pulmonary disease (33% vs 47.2%; P< .05). Other characteristics showing significant differences were the higher frequency of BAC as a chance finding and the lower likelihood of weight loss or reduced performance status at the time of diagnosis. Classification as stage cI was significantly more common in patients with BAC (87% vs 75%; P.001), and this difference between groups was more pronounced for stage pI (68.5% vs 47%; P< .01). Only taking into account patients classified as stage pI with complete resection of NSCLC and following exclusion of operative mortality, patients with BAC presented an overall 5-year survival of 65% (95% confidence interval [CI], 51%-79%), compared with a significantly lower survival of 53% (95% CI, 50%-56%; P< .05) in patients with other forms of NSCLC.
  
  
  CONCLUSIONS
  In Spain, among cases of lung cancer treated by surgery, BAC is very rare (3%) and displays clinical characteristics that are different from other forms of NSCLC. Controlling for the most basic prognostic factors (stage pI and complete resection), survival is significantly higher for BAC.
authors.affiliation: Servicio de Neumología, Hospital Universitario 12 de Octubre, Madrid, España. lencuent@h12o.es
authors.forename: Angel
authors.initials: A
authors.lastname: López Encuentra
authors.forename: Francisco
authors.initials: F
authors.lastname: Pozo Rodríguez
authors.forename: José Luis
authors.initials: JL
authors.lastname: Martín de Nicolás
authors.forename: Victoria
authors.initials: V
authors.lastname: Villena
authors.forename: Javier
authors.initials: J
authors.lastname: Sayas Catalán
mesh_terms: D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000401:mortality / Q000601:surgery; D000368:Aged; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000601:surgery; D008297:Male; D008875:Middle Aged; D013030:Spain