title: Prognostic factors for survival in extensive stage small cell lung cancer (ED-SCLC): the importance of smoking history, socioeconomic and marital statuses, and ethnicity.
abstract: BACKGROUND
  : We investigated whether independent prognostic factors for overall survival (OS) in non-small cell lung cancer such as ethnicity, smoking history, socioeconomic, and marital statuses are also applicable to extensive stage small cell lung cancer (ED-SCLC).
  
  
  METHODS
  : SCLC patients diagnosed from 1991 to 2005 from 3 Southern California counties were identified. Prognostic factors for ED-SCLC patients were evaluated by univariate and multivariate analysis.
  
  
  RESULTS
  : Of the 4782 SCLC patients analyzed, only 2.5% of the patients were never-smokers and 71.7% of patients presented with ED-SCLC. By multivariate analysis, a positive smoking status was a statistically significant poor prognostic factor for OS in ED-SCLC patients (versus never-smoker; hazard ratio [HR] = 1.310; p = 0.0125), in addition low socioeconomic status (SES) (from the lowest to the highest SES score; ptrend = 0.0128) and being unmarried (versus married; HR = 1.179; p < 0.0001). Asian ethnicity was a favorable prognostic factor in ED-SCLC (versus Caucasian; HR = 0.785; p = 0.0076). Female gender was another independent favorable prognostic factor (versus male; HR = 0.823; p < 0.0001).
  
  
  CONCLUSIONS
  : A positive history of smoking, low SES, and being unmarried are independent unfavorable prognostic factors for OS in ED-SCLC while Asian ethnicity and female gender are independent favorable prognostic factors for OS in ED-SCLC by multivariate analysis.
authors.affiliation: Chao Family Comprehensive Cancer Center, Division of Hematology/Oncology, Department of Medicine, University of California Irvine Medical Center, Orange, California, USA. ignatius.ou@uci.edu
authors.forename: Sai-Hong Ignatius
authors.initials: SH
authors.lastname: Ou
authors.forename: Argyrios
authors.initials: A
authors.lastname: Ziogas
authors.forename: Jason A
authors.initials: JA
authors.lastname: Zell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005006:Ethnicity; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology; D008297:Male; D017533:Marital Status; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D055752:Small Cell Lung Carcinoma / Q000401:mortality* / Q000473:pathology; D012907:Smoking / Q000453:epidemiology*; D012923:Social Class; D015996:Survival Rate; D055815:Young Adult