title: Response criteria for NHL: importance of 'normal' lymph node size and correlations with response rates.
abstract: BACKGROUND
  Oncologic literature cites many different definitions of critical response measurements.
  
  
  METHODS
  Response criteria (RC) for non-Hodgkin's lymphoma (NHL) were developed by lymphoma experts, endorsed by international lymphoma clinicians, and applied to a 166-patient rituximab (Rituxan, MabThera) trial by a third-party, blinded panel of NHL experts (LEXCOR). Retrospectively, we analyzed this data using variations of the original RC and comparing with recently published RC.
  
  
  RESULTS
  The definition of a 'normal' lymph node affected the complete response (CR) rate (< or = 1.0 x 1.0 cm, 6%; < or = 1.5 x 1.5 cm, 18%; < or = 2.0 x 2.0 cm, 28%); overall response rate (ORR) was not affected. CR rates increased progressively without > or = 28 days response confirmation: 12% vs. 6% (< or = 1.0 x 1.0 cm), 26% vs. 18% (< or = 1.5 x 1.5 cm), and 36% vs. 28% (< or = 2.0 x 2.0 cm). CR rate and duration of response (DR) were unaffected when only the six largest, rather than all lesions, were measured. When the new RC were applied, CR rate (32%) was higher and DR (13.9 months) and time to progression (15.6 months) were shorter in complete responders.
  
  
  CONCLUSIONS
  Standard RC must be consistently and rigorously applied for accurate comparisons between studies.
authors.affiliation: IDEC Pharmaceuticals Corp., San Diego, California 92121, USA. agrillo@idecpharm.com
authors.forename: A J
authors.initials: AJ
authors.lastname: Grillo-López
authors.forename: B D
authors.initials: BD
authors.lastname: Cheson
authors.forename: S J
authors.initials: SJ
authors.lastname: Horning
authors.forename: B A
authors.initials: BA
authors.lastname: Peterson
authors.forename: W D
authors.initials: WD
authors.lastname: Carter
authors.forename: C L
authors.initials: CL
authors.lastname: Varns
authors.forename: D L
authors.initials: DL
authors.lastname: Klippenstein
authors.forename: C D
authors.initials: CD
authors.lastname: Shen
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents / Q000627:therapeutic use; D018450:Disease Progression; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008228:Lymphoma, Non-Hodgkin / Q000145:classification / Q000188:drug therapy* / Q000473:pathology*; D012016:Reference Values; D012189:Retrospective Studies; D000069283:Rituximab; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D000069283:Rituximab