title: Biologic determinants of tumor recurrence in stage II colon cancer: validation study of the 12-gene recurrence score in cancer and leukemia group B (CALGB) 9581.
abstract: OBJECTIVE
  A greater understanding of the biology of tumor recurrence should improve adjuvant treatment decision making. We conducted a validation study of the 12-gene recurrence score (RS), a quantitative assay integrating stromal response and cell cycle gene expression, in tumor specimens from patients enrolled onto Cancer and Leukemia Group B (CALGB) 9581.
  
  
  METHODS
  CALGB 9581 randomly assigned 1,713 patients with stage II colon cancer to treatment with edrecolomab or observation and found no survival difference. The analysis reported here included all patients with available tissue and recurrence (n = 162) and a random (approximately 1:3) selection of nonrecurring patients. RS was assessed in 690 formalin-fixed paraffin-embedded tumor samples with quantitative reverse transcriptase polymerase chain reaction by using prespecified genes and a previously validated algorithm. Association of RS and recurrence was analyzed by weighted Cox proportional hazards regression.
  
  
  RESULTS
  Continuous RS was significantly associated with risk of recurrence (P = .013) as was mismatch repair (MMR) gene deficiency (P = .044). In multivariate analyses, RS was the strongest predictor of recurrence (P = .004), independent of T stage, MMR, number of nodes examined, grade, and lymphovascular invasion. In T3 MMR-intact (MMR-I) patients, prespecified low and high RS groups had average 5-year recurrence risks of 13% (95% CI, 10% to 16%) and 21% (95% CI, 16% to 26%), respectively.
  
  
  CONCLUSIONS
  The 12-gene RS predicts recurrence in stage II colon cancer in CALGB 9581. This is consistent with the importance of stromal response and cell cycle gene expression in colon tumor recurrence. RS appears to be most discerning for patients with T3 MMR-I tumors, although markers such as grade and lymphovascular invasion did not add value in this subset of patients.
authors.affiliation: University of California San Francisco Cancer Center, 1600 Divisadero Street, San Francisco, CA 94115, USA. venook@cc.ucsf.edu
authors.forename: Alan P
authors.initials: AP
authors.lastname: Venook
authors.forename: Donna
authors.initials: D
authors.lastname: Niedzwiecki
authors.forename: Margarita
authors.initials: M
authors.lastname: Lopatin
authors.forename: Xing
authors.initials: X
authors.lastname: Ye
authors.forename: Mark
authors.initials: M
authors.lastname: Lee
authors.forename: Paula N
authors.initials: PN
authors.lastname: Friedman
authors.forename: Wendy
authors.initials: W
authors.lastname: Frankel
authors.forename: Kim
authors.initials: K
authors.lastname: Clark-Langone
authors.forename: Carl
authors.initials: C
authors.lastname: Millward
authors.forename: Steven
authors.initials: S
authors.lastname: Shak
authors.forename: Richard M
authors.initials: RM
authors.lastname: Goldberg
authors.forename: Najjia N
authors.initials: NN
authors.lastname: Mahmoud
authors.forename: Robert S
authors.initials: RS
authors.lastname: Warren
authors.forename: Richard L
authors.initials: RL
authors.lastname: Schilsky
authors.forename: Monica M
authors.initials: MM
authors.lastname: Bertagnolli
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents / Q000627:therapeutic use; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D053843:DNA Mismatch Repair / Q000235:genetics*; D005260:Female; D006801:Humans; D007938:Leukemia / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000235:genetics*; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; C400149:Edrecolomab