title: Id1 and Id3 co-expression correlates with clinical outcome in stage III-N2 non-small cell lung cancer patients treated with definitive chemoradiotherapy.
abstract: BACKGROUND
  Inhibitor of DNA binding 1 (Id1) and 3 (Id3) genes have been related with the inhibition of cell differentiation, cell growth promotion and tumor metastasis. Recently, Id1 has been identified as an independent prognostic factor in patients with lung adenocarcinoma, regardless of the stage. Furthermore, Id1 may confer resistance to treatment (both, radiotherapy and chemotherapy).
  
  
  METHODS
  We have studied, using monoclonal antibodies for immunohistochemistry, the Id1 and Id3 tumor epithelial expression in 17 patients with stage III-N2 non-small cell lung cancer (NSCLC) treated with definitive chemoradiotherapy.
  
  
  RESULTS
  Id1 expression is observed in 82.4% of the tumors, whereas Id3 expression is present in 41.2% of the samples. Interestingly, Id1 and Id3 expression are mutually correlated (R = 0.579, p = 0.015). In a subgroup analysis of patients with the most locally advanced disease (T4N2 stage), co-expression of Id1 and Id3 showed to be related with a worse overall survival (45 vs 6 months, p = 0.002). A trend towards significance for a worse progression free survival (30 vs 1 months, p = 0.219) and a lower response rate to the treatment (RR = 50% vs 87.5%, p = 0.07) were also observed.
  
  
  CONCLUSIONS
  A correlation between Id1 and Id3 protein expression is observed. Id1 and Id3 co-expression seems associated with a poor clinical outcome in patients with locally advanced NSCLC treated with definitive chemoradiotherapy.
authors: Department of Oncology, Clínica Universidad de Navarra, 31008, Pamplona, Spain.
authors: Eduardo
authors: E
authors: Castañon
authors: Joaquim
authors: J
authors: Bosch-Barrera
authors: Inés
authors: I
authors: López
authors: Víctor
authors: V
authors: Collado
authors: Marta
authors: M
authors: Moreno
authors: José María
authors: JM
authors: López-Picazo
authors: Leire
authors: L
authors: Arbea
authors: María Dolores
authors: MD
authors: Lozano
authors: Alfonso
authors: A
authors: Calvo
authors: Ignacio
authors: I
authors: Gil-Bazo
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000532:radiotherapy*; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D051798:Inhibitor of Differentiation Protein 1 / Q000235:genetics*; D051796:Inhibitor of Differentiation Proteins / Q000235:genetics*; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics*; D016896:Treatment Outcome
chemical_list: C497453:ID1 protein, human; D051798:Inhibitor of Differentiation Protein 1; D051796:Inhibitor of Differentiation Proteins; D009363:Neoplasm Proteins; C075640:ID3 protein, human