title: Prognosis of localized diffuse large B-cell lymphoma in younger patients.
abstract: BACKGROUND
  The International Prognostic Index (IPI) is widely used as a predictive model in diffuse large B-cell lymphoma (DLBCL) patients of all ages and stages. To determine the optimal IPI-based prognostic system at the time of diagnosis in younger patients with limited-stage DLBCL, the authors evaluated the age-adjusted IPI and the recently proposed stage-adjusted IPI, and constructed an IPI-based model adjusted for both age and stage.
  
  
  METHODS
  From the population-based LYFO registry of the Danish Lymphoma Group, 233 patients not older than 60 years with Stage I-II DLBCL treated with anthracycline-based chemotherapy with or without involved-field irradiation were identified. The primary endpoint of analysis was overall survival.
  
  
  RESULTS
  At the end of the observation period, 151 patients were alive with a median follow-up time of 8.3 years. All the variables in the age-adjusted and the stage-adjusted IPI had major prognostic significance (P < or = 0.0001). Log-rank analyses of survival showed highly significant differences between the subgroups in each model (P < 0.0001); however, the stage-adjusted IPI was more powerful (chi-square test = 44.99) than the age-adjusted IPI (chi-square test = 36.27). By using the median age of the cohort (50 years) as a cutoff point, age was found to be a strong prognostic factor (P = 0.0036). An age-/stage-adjusted IPI was constructed, the predictive power of which was equal to the stage-adjusted IPI (chi-square test = 44.16) but with different distribution of patients between the risk groups, making the proposed model better suited to identify poor-risk patients.
  
  
  CONCLUSIONS
  The data from the current study suggest that the proposed age-/stage-adjusted IPI is the superior IPI-based model in predicting outcome in younger patients with localized DLBCL.
authors.affiliation: Department of Pathology, Odense University Hospital, Odense, Denmark. m.moller@imbmed.sdu.dk
authors.forename: Michael B
authors.initials: MB
authors.lastname: Møller
authors.forename: Bjarne E
authors.initials: BE
authors.lastname: Christensen
authors.forename: Niels T
authors.initials: NT
authors.lastname: Pedersen
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D003718:Denmark; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016393:Lymphoma, B-Cell / Q000175:diagnosis* / Q000188:drug therapy; D016403:Lymphoma, Large B-Cell, Diffuse / Q000175:diagnosis* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011159:Population Surveillance; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D015996:Survival Rate