title: MicroRNA-21 predicts response to preoperative chemoradiotherapy in locally advanced rectal cancer.
abstract: OBJECTIVE
  The treatment of choice for locally advanced rectal cancer is preoperative chemoradiotherapy. Despite half of patients do not respond and suffer unnecessary toxicities and surgery delays, there are no biomarkers to guide preoperative CRT outcome. MicroRNA-21 has been related to acquisition of 5-fluorouracil resistance; however, its potential predictive value of response to preoperative chemoradiotherapy in locally advanced rectal cancer remains unknown.
  
  
  METHODS
  Nighty-two patients diagnosed with locally advanced rectal cancer who were preoperatively treated with chemoradiotherapy were selected for this study. Moreover, microRNA-21 expression was quantified in formalin-fixed paraffin-embedded biopsies from this cohort, and the results obtained were correlated with clinical and molecular characteristics, pathological response, and outcome.
  
  
  RESULTS
  MicroRNA-21 was found overexpressed in 77.6% cases, and significantly correlated with tumor grade after preoperative chemoradiotherapy (P = 0.013) and with pathological response (P = 0.013). The odds ratio of having miR-21 overexpression and not getting a respond to chemoradiotherapy resulted in 9.75 CI 2.24 to 42. Sensitivity, specificity, negative predictive values, and positive predictive value were 86.6, 60, 42.8, and 92%, respectively. Multivariate analysis confirmed the clinical significance of miR-21 determining preoperative chemoradiotherapy response.
  
  
  CONCLUSIONS
  MicroRNA-21 expression efficiently predicts preoperative chemoradiotherapy pathological response in locally advanced rectal cancer.
authors.affiliation: Medical Oncology Department, University Hospital "Fundación Jimenez Diaz", Avda. Reyes Católicos-2, 28040, Madrid, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Caramés
authors.forename: Ion
authors.initials: I
authors.lastname: Cristóbal
authors.forename: Víctor
authors.initials: V
authors.lastname: Moreno
authors.forename: Laura
authors.initials: L
authors.lastname: del Puerto
authors.forename: Irene
authors.initials: I
authors.lastname: Moreno
authors.forename: María
authors.initials: M
authors.lastname: Rodriguez
authors.forename: Juan P
authors.initials: JP
authors.lastname: Marín
authors.forename: Andrea V
authors.initials: AV
authors.lastname: Correa
authors.forename: Roberto
authors.initials: R
authors.lastname: Hernández
authors.forename: Víctor
authors.initials: V
authors.lastname: Zenzola
authors.forename: Tatiana
authors.initials: T
authors.lastname: Hernández
authors.forename: Ana
authors.initials: A
authors.lastname: León
authors.forename: José I
authors.initials: JI
authors.lastname: Martín
authors.forename: Paloma
authors.initials: P
authors.lastname: Sánchez-Fayos
authors.forename: Damián
authors.initials: D
authors.lastname: García-Olmo
authors.forename: Federico
authors.initials: F
authors.lastname: Rojo
authors.forename: Ajay
authors.initials: A
authors.lastname: Goel
authors.forename: María J
authors.initials: MJ
authors.lastname: Fernandez-Aceñero
authors.forename: Jesús
authors.initials: J
authors.lastname: García-Foncillas
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D059248:Chemoradiotherapy; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D016015:Logistic Models; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D012372:ROC Curve; D012004:Rectal Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs