title: Prognosis in adult indolent systemic mastocytosis: a long-term study of the Spanish Network on Mastocytosis in a series of 145 patients.
abstract: BACKGROUND
  Indolent systemic mastocytosis is a group of rare diseases for which reliable predictors of progression and outcome are still lacking.
  
  
  OBJECTIVE
  Here we investigate the prognostic impact of the clinical, biological, phenotypic, histopathological, and molecular disease characteristics in adults with indolent systemic mastocytosis, who were followed using conservative therapy.
  
  
  METHODS
  A total of 145 consecutive patients were prospectively followed between January 1983 and July 2008; in addition, from 1967 to 1983, 20 patients were retrospectively studied.
  
  
  RESULTS
  Multivariate analysis showed that serum beta2-microglobulin (P = .003) together with the presence of mast/stem cell growth factor receptor gene (KIT) mutation in mast cells plus myeloid and lymphoid hematopoietic lineages (P = .02) was the best combination of independent parameters for predicting disease progression (cumulative probability of disease progression of 1.7% +/- 1.2% at 5-10 years and of 8.4% +/- 5.0% at 20-25 years). Regarding overall survival, the best predictive model included age >60 years (P = .005) and development of an associated clonal hematological non-mast cell disorder (P = .03) with a cumulative probability of death of 2.2% +/- 1.3% at 5 years and of 11% +/- 5.9% at 25 years.
  
  
  CONCLUSIONS
  Indolent systemic mastocytosis in adults has a low disease progression rate, and the great majority of patients have a normal life expectancy, with the presence of KIT mutation in all hematopoietic lineages and increased serum beta2-microglobulin the most powerful independent parameters for predicting transformation into a more aggressive form of the disease.
authors.affiliation: Centro de Estudios de Mastocitosis de Castilla La Mancha, Hospital Virgen del Valle, Toledo, Spain. lescribanom@sescam.jccm.es
authors.forename: Luis
authors.initials: L
authors.lastname: Escribano
authors.forename: Iván
authors.initials: I
authors.lastname: Alvarez-Twose
authors.forename: Laura
authors.initials: L
authors.lastname: Sánchez-Muñoz
authors.forename: Andres
authors.initials: A
authors.lastname: Garcia-Montero
authors.forename: Rosa
authors.initials: R
authors.lastname: Núñez
authors.forename: Julia
authors.initials: J
authors.lastname: Almeida
authors.forename: Maria
authors.initials: M
authors.lastname: Jara-Acevedo
authors.forename: Cristina
authors.initials: C
authors.lastname: Teodósio
authors.forename: Mónica
authors.initials: M
authors.lastname: García-Cosío
authors.forename: Carmen
authors.initials: C
authors.lastname: Bellas
authors.forename: Alberto
authors.initials: A
authors.lastname: Orfao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D018450:Disease Progression; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006918:Hydroxyurea / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008407:Mast Cells / Q000276:immunology*; D034721:Mastocytosis, Systemic / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology*; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011446:Prospective Studies; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011994:Recombinant Proteins; D012189:Retrospective Studies; D055815:Young Adult; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D000998:Antiviral Agents; D004791:Enzyme Inhibitors; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D001613:beta 2-Microglobulin; D019009:Proto-Oncogene Proteins c-kit; D006918:Hydroxyurea