title: Prognostic role of hyponatremia in 564 small cell lung cancer patients treated with topotecan.
abstract: OBJECTIVE
  Hyponatremia is reported in about 15% of small cell lung cancer (SCLC). Variable results of the prognostic significance of low plasmatic sodium (Napl) have been reported. Our study was performed to investigate the prognostic role of hyponatremia in SCLC patients treated in second-line with topotecan chemotherapy.
  
  
  METHODS
  Data were retrospectively collected from a database including clinical data from 631 patients enrolled in 6 prospective topotecan iv studies. Final data were obtained from 564 patients in which data on baseline Napl were available. Univariate and multivariate analysis were carried out to study the possible correlation between Napl and second-line clinical outcomes.
  
  
  RESULTS
  Hyponatremia (Napl<135mequiv./l) was present in 101 cases (17.9%). Napl was <125mequiv./l in 16 patients (2.8%), 126-130mequiv./l in 11 (2%), 130-134mequiv./l in 74 (13.1%), while 463 patients (82.1%) showed normal values. The median survival was 28.7 weeks in patients with normal Napl, and 21.1 weeks in patients with hyponatremia (p<0.0001, HR=1.67, 95%CI=1.32-2.10). By Cox multivariate analysis, hyponatremia was associated with poorer prognosis (p=0.0024, HR=1.44, 95%CI=1.13-1.82). A not statistically significant trend of correlation between hyponatremia and progression-free survival (p=0.085, HR=1.23, 95%CI 0.97-1.55) and response rate (p=0.5037, OR=0.81, 95%CI 0.44-1.49) was observed.
  
  
  CONCLUSIONS
  Hyponatremia is an independent prognostic factor for patients with SCLC treated with topotecan in second-line setting. Further studies are needed to prospectically confirm these results and to develop an optimal therapy for hyponatremic patients.
authors.affiliation: Oncology Unit, University Hospital of Parma, Viale Antonio Gramsci, 14, 43126 Parma, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Tiseo
authors.affiliation: Oncology Unit, University Hospital of Parma, Viale Antonio Gramsci, 14, 43126 Parma, Italy. Electronic address: sebabuti@libero.it.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Buti
authors.affiliation: Clinical Trials Coordinating Center, Istituto Toscano Tumori Core Research Laboratory, Department of Oncology, University Hospital of Careggi, via Taddeo Alderotti 26/N, 50139 Firenze, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Boni
authors.affiliation: Oncology Unit, University Hospital of Parma, Viale Antonio Gramsci, 14, 43126 Parma, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mattioni
authors.affiliation: Oncology Unit, University Hospital of Parma, Viale Antonio Gramsci, 14, 43126 Parma, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ardizzoni
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis / Q000209:etiology*; D008175:Lung Neoplasms / Q000150:complications* / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D055752:Small Cell Lung Carcinoma / Q000150:complications* / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D059004:Topoisomerase I Inhibitors / Q000627:therapeutic use; D019772:Topotecan / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D059004:Topoisomerase I Inhibitors; D019772:Topotecan
keywords: Hyponatremia; Prognostic; Second-line; Serum sodium (Na(pl)); Small cell lung cancer; Topotecan