title: A comparative analysis of prognostic factor models for follicular lymphoma based on a phase III trial of CHOP-rituximab versus CHOP + 131iodine--tositumomab.
abstract: OBJECTIVE
  There is currently no consensus on optimal frontline therapy for patients with follicular lymphoma. We analyzed a phase III randomized intergroup trial comparing six cycles of CHOP-R (cyclophosphamide-Adriamycin-vincristine-prednisone (Oncovin)-rituximab) with six cycles of CHOP followed by iodine-131 tositumomab radioimmunotherapy (RIT) to assess whether any subsets benefited more from one treatment or the other, and to compare three prognostic models.
  
  
  METHODS
  We conducted univariate and multivariate Cox regression analyses of 532 patients enrolled on this trial and compared the prognostic value of the FLIPI (follicular lymphoma international prognostic index), FLIPI2, and LDH + β2M (lactate dehydrogenase + β2-microglobulin) models.
  
  
  RESULTS
  Outcomes were excellent, but not statistically different between the two study arms [5-year progression-free survival (PFS) of 60% with CHOP-R and 66% with CHOP-RIT (P = 0.11); 5-year overall survival (OS) of 92% with CHOP-R and 86% with CHOP-RIT (P = 0.08); overall response rate of 84% for both arms]. The only factor found to potentially predict the impact of treatment was serum β2M; among patients with normal β2M, CHOP-RIT patients had better PFS compared with CHOP-R patients, whereas among patients with high serum β2M, PFS by arm was similar (interaction P value = 0.02).
  
  
  CONCLUSIONS
  All three prognostic models (FLIPI, FLIPI2, and LDH + β2M) predicted both PFS and OS well, though the LDH + β2M model is easiest to apply and identified an especially poor risk subset. In an exploratory analysis using the latter model, there was a statistically significant trend suggesting that low-risk patients had superior observed PFS if treated with CHOP-RIT, whereas high-risk patients had a better PFS with CHOP-R.
authors.affiliation: Authors' Affiliations: Clinical Research Division; SWOG Statistical Center, Fred Hutchinson Cancer Research Center; Medical Oncology, University of Washington Medical Center, Seattle, Washington; Department of Pathology; Arizona Cancer Center, University of Arizona, Tucson, Arizona; James P. Wilmot Cancer Center, University of Rochester Medical Center, Rochester; Roswell Park Cancer Institute, Buffalo, New York; Cancer and Leukemia Group B; University of Michigan, Ann Arbor, Michigan; Department of Pathology, Oregon Health and Science University, Portland, Oregon; Georgetown University Hospital, Washington; Wichita Community Clinical Oncology Program, Wichita, Kansas; and Fox Chase Cancer Center-Temple Health, Temple University, Philadelphia PA.
authors.forename: Oliver W
authors.initials: OW
authors.lastname: Press
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Unger
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Rimsza
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Friedberg
authors.forename: Michael
authors.initials: M
authors.lastname: LeBlanc
authors.forename: Myron S
authors.initials: MS
authors.lastname: Czuczman
authors.forename: Mark
authors.initials: M
authors.lastname: Kaminski
authors.forename: Rita M
authors.initials: RM
authors.lastname: Braziel
authors.forename: Catherine
authors.initials: C
authors.lastname: Spier
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Gopal
authors.forename: David G
authors.initials: DG
authors.lastname: Maloney
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Cheson
authors.forename: Shaker R
authors.initials: SR
authors.lastname: Dakhil
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Miller
authors.forename: Richard I
authors.initials: RI
authors.lastname: Fisher
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017326:Clinical Trials, Phase III as Topic; D003520:Cyclophosphamide / Q000008:administration & dosage; D018572:Disease-Free Survival; D004317:Doxorubicin / Q000008:administration & dosage; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology; D008224:Lymphoma, Follicular / Q000097:blood / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology; D008875:Middle Aged; D015999:Multivariate Analysis; D009929:Organ Size; D011241:Prednisone / Q000008:administration & dosage; D011379:Prognosis; D016016:Proportional Hazards Models; D000069283:Rituximab; D014750:Vincristine / Q000008:administration & dosage; D055815:Young Adult; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D006454:Hemoglobins; D001613:beta 2-Microglobulin; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; C119496:tositumomab I-131; D011241:Prednisone