title: Genomic Grade Index (GGI): feasibility in routine practice and impact on treatment decisions in early breast cancer.
abstract: OBJECTIVE
  Genomic Grade Index (GGI) is a 97-gene signature that improves histologic grade (HG) classification in invasive breast carcinoma. In this prospective study we sought to evaluate the feasibility of performing GGI in routine clinical practice and its impact on treatment recommendations.
  
  
  METHODS
  Patients with pT1pT2 or operable pT3, N0-3 invasive breast carcinoma were recruited from 8 centers in Belgium. Fresh surgical samples were sent at room temperature in the MapQuant Dx™ PathKit for centralized genomic analysis. Genomic profiles were determined using Affymetrix U133 Plus 2.0 and GGI calculated using the MapQuant Dx® protocol, which defines tumors as low or high Genomic Grade (GG-1 and GG-3 respectively).
  
  
  RESULTS
  180 pts were recruited and 155 were eligible. The MapQuant test was performed in 142 cases and GGI was obtained in 78% of cases (n=111). Reasons for failures were 15 samples with <30% of invasive tumor cells (11%), 15 with insufficient RNA quality (10%), and 1 failed hybridization (<1%). For tumors with an available representative sample (≥ 30% inv. tumor cells) (n=127), the success rate was 87.5%. GGI reclassified 69% of the 54 HG2 tumors as GG-1 (54%) or GG-3 (46%). Changes in treatment recommendations occurred mainly in the subset of HG2 tumors reclassified into GG-3, with increased use of chemotherapy in this subset.
  
  
  CONCLUSIONS
  The use of GGI is feasible in routine clinical practice and impacts treatment decisions in early-stage breast cancer.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01916837, http://clinicaltrials.gov/ct2/show/NCT01916837.
authors.affiliation: Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Otto
authors.initials: O
authors.lastname: Metzger-Filho
authors.forename: Aurélie
authors.initials: A
authors.lastname: Catteau
authors.forename: Stefan
authors.initials: S
authors.lastname: Michiels
authors.forename: Marc
authors.initials: M
authors.lastname: Buyse
authors.forename: Michail
authors.initials: M
authors.lastname: Ignatiadis
authors.forename: Kamal S
authors.initials: KS
authors.lastname: Saini
authors.forename: Evandro
authors.initials: E
authors.lastname: de Azambuja
authors.forename: Virginie
authors.initials: V
authors.lastname: Fasolo
authors.forename: Sihem
authors.initials: S
authors.lastname: Naji
authors.forename: Jean Luc
authors.initials: JL
authors.lastname: Canon
authors.forename: Paul
authors.initials: P
authors.lastname: Delrée
authors.forename: Michel
authors.initials: M
authors.lastname: Coibion
authors.forename: Pino
authors.initials: P
authors.lastname: Cusumano
authors.forename: Veronique
authors.initials: V
authors.lastname: Jossa
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Kains
authors.forename: Denis
authors.initials: D
authors.lastname: Larsimont
authors.forename: Vincent
authors.initials: V
authors.lastname: Richard
authors.forename: Daniel
authors.initials: D
authors.lastname: Faverly
authors.forename: Nathalie
authors.initials: N
authors.lastname: Cornez
authors.forename: Peter
authors.initials: P
authors.lastname: Vuylsteke
authors.forename: Brigitte
authors.initials: B
authors.lastname: Vanderschueren
authors.forename: Hélène
authors.initials: H
authors.lastname: Peyro-Saint-Paul
authors.forename: Martine
authors.initials: M
authors.lastname: Piccart
authors.forename: Christos
authors.initials: C
authors.lastname: Sotiriou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001530:Belgium; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002277:Carcinoma / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D003657:Decision Making; D005240:Feasibility Studies; D005260:Female; D023281:Genomics; D006764:Hospitals, Community; D006801:Humans; D008875:Middle Aged; D060787:Neoplasm Grading / Q000379:methods*; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D011446:Prospective Studies; D013696:Temperature