title: Long-term survival in small cell lung cancer patients is correlated with high interleukin-2 secretion at diagnosis.
abstract: OBJECTIVE
  We have previously reported significant impairment of IL-2 secretion in patients with small cell lung cancer (SCLC) at the time of diagnosis. Impairment of IL-2 secretion correlated with reduced survival in SCLC. This new prognostic factor was independent of other factors of prognostic relevance in SCLC. The prognostic value of IL-2 secretion was comparable to the most predominant prognostic factors for survival in SCLC identified so far. We now report long-term survival data from these patients.
  
  
  METHODS
  The significance of correlations between single parameters in the test groups was calculated by using linear regression analysis, the Wilcoxon rank sum test, and Fisher's exact test. Using the Kaplan-Meier method, the log-rank test and the Cox regression model, we analyzed the relation of IL-2 secretion in whole blood cell cultures from 52 patients with SCLC at the time of diagnosis to established prognostic factors relevant for survival in SCLC.
  
  
  RESULTS
  IL-2 secretion correlates with survival in SCLC. In addition, survival analysis according to tumor response and level of IL-2 secretion at the time of diagnosis demonstrates that long-term survival can only be observed after complete response to chemotherapy and high initial IL-2 secretion.
  
  
  CONCLUSIONS
  IL-2 secretion at the time of diagnosis represents an independent prognostic factor for survival in SCLC. Moreover, long-term survival is only observed in patients with complete response upon chemotherapy that showed high IL-2 secretion at diagnosis. Therefore, IL-2 secretion may partially define long-term survival in this disease. These results have to be confirmed in a larger patient population.
authors.affiliation: Thoraxklinik-Heidelberg GmbH, Department of Medical Oncology, Amalienstrasse 5, 69126 Heidelberg-Rohrbach, Germany. JR.Fischer@DKFZ-Heidelberg.de
authors.forename: J R
authors.initials: JR
authors.lastname: Fischer
authors.forename: M
authors.initials: M
authors.lastname: Schindel
authors.forename: H
authors.initials: H
authors.lastname: Bülzebruck
authors.forename: H
authors.initials: H
authors.lastname: Lahm
authors.forename: P H
authors.initials: PH
authors.lastname: Krammer
authors.forename: P
authors.initials: P
authors.lastname: Drings
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology* / Q000401:mortality*; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism*; D008175:Lung Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D007376:Interleukin-2