title: Hyponatremia as prognostic factor in small cell lung cancer--a retrospective single institution analysis.
abstract: OBJECTIVE
  The aim of this retrospective study is to present data on clinical significance of hyponatremia in an unselected contemporary patient population with small cell lung cancer (SCLC) with limited disease (LD) and extensive disease (ED).
  
  
  METHODS
  Our electronic database was searched for patients with newly diagnosed SCLC from June 2004 to December 2008. 395 cases were identified. We collected data on patient characteristics including clinical performance status, serum sodium values, serum LDH values, metastatic sites, chemotherapy regimens and response, radiotherapy and survival.
  
  
  RESULTS
  Hyponatremia (sodium <135 mmol/l) was present in 18.9% of all cases. Severe hyponatremia (sodium <129 mmol/l) was detected in 8.8%. Hyponatremia was present in 58 out of 241 (24%) patients with ED SCLC and 17 of 154 (11%) patients with LD SCLC. Hyponatremia was associated with significantly shorter median survival (SCLC all patients: 9.0 vs. 13.0 months, p < 0.001, LD SCLC: 9.0 vs. 17.0, p = 0.050, ED SCLC 9.0 vs. 10.0, p = 0.135). After adjustment for age, gender, LDH and performance status hyponatremia was an independent predictor of mortality in patients with ED and LD SCLC.
  
  
  CONCLUSIONS
  According to the extensive statistical analyses in our comprehensive unselected patient population, hyponatremia seems to constitute an independent prognostic factor in patients with SCLC.
authors.affiliation: Department of Thoracic Oncology, Grosshansdorf Hospital, Woehrendamm 80, 22927 Grosshansdorf, Germany. pahermes@hotmail.com
authors.forename: Andreas
authors.initials: A
authors.lastname: Hermes
authors.forename: Benjamin
authors.initials: B
authors.lastname: Waschki
authors.forename: Martin
authors.initials: M
authors.lastname: Reck
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000209:etiology*; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008175:Lung Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D055752:Small Cell Lung Carcinoma / Q000150:complications* / Q000175:diagnosis / Q000556:secondary / Q000628:therapy; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D007770:L-Lactate Dehydrogenase