title: [Clinicopathological features, prognosis and influence in the adjuvant treatment of the risk recurrence groups determined by the 21 gene expression profile, Oncotype Dx®, in early breast cancer].
abstract: BACKGROUND
  Adjuvant chemotherapy (ACT) reduces recurrence and mortality in breast cancer (BC); however, not all patients require ACT. Oncotype Dx® (ODX) explores the expression of 21 genes and the risk of recurrence BC.
  
  
  OBJECTIVE
  To determine the clinicopathologic characteristics, prognosis, and the prescription for ACT in early BC according to ODX risk groups.
  
  
  METHODS
  36 patients with resected stage I-IIA BC, axillary lymph node-negative or 1-3+, hormonal receptor (HR)-positive, HER2 negative. Three groups were designed by ODX: low (LG), medium (MG) and high-risk groups (HG).
  
  
  RESULTS
  LG 23 patients (63.9%), MG eight (22.2%) and HG five (13.9%). We detected high expression of Ki-67 in MG and HG in relation to LG, 21.1 and 32.5 versus 10.1%, respectively (p = 0.007) and lower ER-positive, 85.3, 85.4 and 56.9%, respectively (p = 0.005). Recurrence score: LG 12 (0-18), MG 23 (19-27) and HG 47 (36-57); p < 0.000. Pre-ODX, we planned ACT in 21/36 patients (58.3%) and post-ODX only 9/36 patients (25%) received it. No recurrences or deaths were observed in all groups.
  
  
  CONCLUSIONS
  In early BC, 64% have low recurrence risk. High-risk cases presented elevated Ki-67 and lower ER expression. ODX modifies the therapeutic recommendation in 57.2% of cases.
authors.affiliation: Departamento de Oncología Médica, Centro de Cáncer, Centro Médico ABC, México. serranoolvera@yahoo.com.mx
authors.forename: Raquel
authors.initials: R
authors.lastname: Gerson Cwilich
authors.forename: Luis Fernando
authors.initials: LF
authors.lastname: Alban de la Torre
authors.forename: Alberto
authors.initials: A
authors.lastname: Villalobos Prieto
authors.forename: Juan Alberto
authors.initials: JA
authors.lastname: Serrano Olvera
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000235:genetics*; D011379:Prognosis; D011446:Prospective Studies; D012306:Risk