title: Integration of gene mutations in risk prognostication for patients receiving first-line immunochemotherapy for follicular lymphoma: a retrospective analysis of a prospective clinical trial and validation in a population-based registry.
abstract: BACKGROUND
  Follicular lymphoma is a clinically and genetically heterogeneous disease, but the prognostic value of somatic mutations has not been systematically assessed. We aimed to improve risk stratification of patients receiving first-line immunochemotherapy by integrating gene mutations into a prognostic model.
  
  
  METHODS
  We did DNA deep sequencing to retrospectively analyse the mutation status of 74 genes in 151 follicular lymphoma biopsy specimens that were obtained from patients within 1 year before beginning immunochemotherapy consisting of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). These patients were recruited between May 4, 2000, and Oct 20, 2010, as part of a phase 3 trial (GLSG2000). Eligible patients had symptomatic, advanced stage follicular lymphoma and were previously untreated. The primary endpoints were failure-free survival (defined as less than a partial remission at the end of induction, relapse, progression, or death) and overall survival calculated from date of treatment initiation. Median follow-up was 7·7 years (IQR 5·5-9·3). Mutations and clinical factors were incorporated into a risk model for failure-free survival using multivariable L1-penalised Cox regression. We validated the risk model in an independent population-based cohort of 107 patients with symptomatic follicular lymphoma considered ineligible for curative irradiation. Pretreatment biopsies were taken between Feb 24, 2004, and Nov 24, 2009, within 1 year before beginning first-line immunochemotherapy consisting of rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP). Median follow-up was 6·7 years (IQR 5·7-7·6).
  
  
  RESULTS
  We established a clinicogenetic risk model (termed m7-FLIPI) that included the mutation status of seven genes (EZH2, ARID1A, MEF2B, EP300, FOXO1, CREBBP, and CARD11), the Follicular Lymphoma International Prognostic Index (FLIPI), and Eastern Cooperative Oncology Group (ECOG) performance status. In the training cohort, m7-FLIPI defined a high-risk group (28%, 43/151) with 5-year failure-free survival of 38·29% (95% CI 25·31-57·95) versus 77·21% (95% CI 69·21-86·14) for the low-risk group (hazard ratio [HR] 4·14, 95% CI 2·47-6·93; p<0·0001; bootstrap-corrected HR 2·02), and outperformed a prognostic model of only gene mutations (HR 3·76, 95% CI 2·10-6·74; p<0·0001; bootstrap-corrected HR 1·57). The positive predictive value and negative predictive value for 5-year failure-free survival were 64% and 78%, respectively, with a C-index of 0·80 (95% CI 0·71-0·89). In the validation cohort, m7-FLIPI again defined a high-risk group (22%, 24/107) with 5-year failure-free survival of 25·00% (95% CI 12·50-49·99) versus 68·24% (58·84-79·15) in the low-risk group (HR 3·58, 95% CI 2·00-6·42; p<0.0001). The positive predictive value for 5-year failure-free survival was 72% and 68% for negative predictive value, with a C-index of 0·79 (95% CI 0·69-0·89). In the validation cohort, risk stratification by m7-FLIPI outperformed FLIPI alone (HR 2·18, 95% CI 1·21-3·92), and FLIPI combined with ECOG performance status (HR 2·03, 95% CI 1·12-3·67).
  
  
  CONCLUSIONS
  Integration of the mutational status of seven genes with clinical risk factors improves prognostication for patients with follicular lymphoma receiving first-line immunochemotherapy and is a promising approach to identify the subset at highest risk of treatment failure.
  
  
  BACKGROUND
  Deutsche Krebshilfe, Terry Fox Research Institute.
authors.affiliation: Department of Internal Medicine III, University Hospital of the Ludwig-Maximilians-University Munich, Munich, Germany.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pastore
authors.affiliation: Department of Internal Medicine III, University Hospital of the Ludwig-Maximilians-University Munich, Munich, Germany; Institute for Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-University Munich, Munich, Germany.
authors.forename: Vindi
authors.initials: V
authors.lastname: Jurinovic
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Kridel
authors.affiliation: Department of Internal Medicine III, University Hospital of the Ludwig-Maximilians-University Munich, Munich, Germany; Institute for Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-University Munich, Munich, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Hoster
authors.affiliation: Department of Clinical Pathology, Robert-Bosch-Krankenhaus, Stuttgart, Germany; Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany; University of Tübingen, Tübingen, Germany.
authors.forename: Annette M
authors.initials: AM
authors.lastname: Staiger
authors.affiliation: Haematopathology Section, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Szczepanowski
authors.affiliation: Second Medical Department, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Pott
authors.affiliation: Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Nadja
authors.initials: N
authors.lastname: Kopp
authors.affiliation: Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Department of Clinical Pathology, Robert-Bosch-Krankenhaus, Stuttgart, Germany; Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany; University of Tübingen, Tübingen, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Horn
authors.affiliation: Institute of Pathology, University of Würzburg, and Comprehensive Cancer Center Mainfranken, Würzburg, Germany.
authors.forename: Ellen
authors.initials: E
authors.lastname: Leich
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Alden A
authors.initials: AA
authors.lastname: Moccia
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Anja
authors.initials: A
authors.lastname: Mottok
authors.affiliation: Center for Cancer Genome Discovery, Boston, MA, USA; Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Ashwini
authors.initials: A
authors.lastname: Sunkavalli
authors.affiliation: Center for Cancer Genome Discovery, Boston, MA, USA; Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Van Hummelen
authors.affiliation: Center for Cancer Genome Discovery, Boston, MA, USA; Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Ducar
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ennishi
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Hennady P
authors.initials: HP
authors.lastname: Shulha
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Christoffer
authors.initials: C
authors.lastname: Hother
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Connors
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Laurie H
authors.initials: LH
authors.lastname: Sehn
authors.affiliation: Department of Internal Medicine III, University Hospital of the Ludwig-Maximilians-University Munich, Munich, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Dreyling
authors.affiliation: Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Donna
authors.initials: D
authors.lastname: Neuberg
authors.affiliation: Institute of Pathology, University of Ulm, Ulm, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Möller
authors.affiliation: Department of Pathology, University Hospital of Schleswig-Holstein, Lübeck, Germany.
authors.forename: Alfred C
authors.initials: AC
authors.lastname: Feller
authors.affiliation: Senckenberg Institute of Pathology, Goethe University, Frankfurt am Main, Germany.
authors.forename: Martin L
authors.initials: ML
authors.lastname: Hansmann
authors.affiliation: Berlin Reference Center for Lymphoma and Haematopathology, Berlin, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Stein
authors.affiliation: Institute of Pathology, University of Würzburg, and Comprehensive Cancer Center Mainfranken, Würzburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rosenwald
authors.affiliation: Department of Clinical Pathology, Robert-Bosch-Krankenhaus, Stuttgart, Germany.
authors.forename: German
authors.initials: G
authors.lastname: Ott
authors.affiliation: Haematopathology Section, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Klapper
authors.affiliation: Department of Internal Medicine III, University Hospital of the Ludwig-Maximilians-University Munich, Munich, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Unterhalt
authors.affiliation: Department of Internal Medicine III, University Hospital of the Ludwig-Maximilians-University Munich, Munich, Germany; Clinical Cooperative Group Leukemia, Helmholtz-Center Munich, Munich, Germany; German Cancer Consortium (DKTK), Heidelberg, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hiddemann
authors.affiliation: Department of Lymphoid Cancer Research and the Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Randy D
authors.initials: RD
authors.lastname: Gascoyne
authors.affiliation: Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Weinstock
authors.affiliation: Department of Internal Medicine III, University Hospital of the Ludwig-Maximilians-University Munich, Munich, Germany; Clinical Cooperative Group Leukemia, Helmholtz-Center Munich, Munich, Germany; German Cancer Consortium (DKTK), Heidelberg, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany. Electronic address: oliver.weigert@med.uni-muenchen.de.
authors.forename: Oliver
authors.initials: O
authors.lastname: Weigert
mesh_terms: D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage* / Q000276:immunology; D003520:Cyclophosphamide / Q000008:administration & dosage; D018572:Disease-Free Survival; D004317:Doxorubicin; D005260:Female; D006801:Humans; D007167:Immunotherapy; D008224:Lymphoma, Follicular / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D011241:Prednisone / Q000008:administration & dosage; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone