title: Indolent lymphoplasmacytic and marginal zone B-cell lymphomas: absence of both IRF4 and Ki67 expression identifies a better prognosis subgroup.
abstract: OBJECTIVE
  Small B-cell indolent lymphomas postulated to be of a post-germinal center origin include marginal zone lymphomas of the spleen (S-MZL) or lymph nodes (N-MZL) and mucosa-associated lymphoid tissue (MALT) lymphomas and lymphoplasmacytic lymphomas (LPL). The existence of rather aggressive cases stresses the need for new biological prognostic markers.
  
  
  METHODS
  We analyzed 90 tumors (20 LPL, 41 MALT lymphomas, 12 N-MZL, 17 S-MZL), investigating the expression of CD5, CD10, CD20, CD23, CD27, CD38, CD79a, CD138, Bcl6, cyclin D1, IRF4 and Ki67 antigens by immunohistochemistry. Results were compared to the histology, the standard clinical and biological parameters, and the global survival.
  
  
  RESULTS
  Tumors were all positive for CD20 and CD79a, occasionally positive for CD5, CD23, CD138 and cyclin D1, and all negative for Bcl-6 and CD10. CD38, CD27 and IRF4 expression was heterogeneous. IRF4 expression was correlated with plasma-cell differentiation (p=0.0017). Ki67 expression was increased mainly in N-MZL (66%) and LPL (45%). In terms of overall survival, Ki67, IRF4 and C-reactive protein levels were found to be the 3 independent parameters associated with a worse outcome. Lack of both Ki67 and IRF4 expression was associated with a longer survival (median overall survival 9.8+/-1.1 years versus 3.6+/-1.3 years in the other group) (p=0.0011).
  
  
  CONCLUSIONS
  Absence of expression of both Ki67 and IRF4 is likely to define a group of memory B-cell lymphomas with a better prognosis. This may have an important impact in the staging of patients since expression of these markers is easily assessed in routine diagnosis.
authors.affiliation: Laboratoire d'Anatomie Pathologique, France.
authors.forename: Barbara
authors.initials: B
authors.lastname: Petit
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Chaury
authors.forename: Christophe
authors.initials: C
authors.lastname: Le Clorennec
authors.forename: Arnaud
authors.initials: A
authors.lastname: Jaccard
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gachard
authors.forename: Sandra
authors.initials: S
authors.lastname: Moalic-Judge
authors.forename: François
authors.initials: F
authors.lastname: Labrousse
authors.forename: Michel
authors.initials: M
authors.lastname: Cogné
authors.forename: Dominique
authors.initials: D
authors.lastname: Bordessoule
authors.forename: Jean
authors.initials: J
authors.lastname: Feuillard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D050835:Interferon Regulatory Factors / Q000096:biosynthesis*; D019394:Ki-67 Antigen / Q000096:biosynthesis*; D008223:Lymphoma / Q000175:diagnosis / Q000378:metabolism*; D016393:Lymphoma, B-Cell / Q000175:diagnosis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D000099218:Interferon Regulatory Factor-4
chemical_list: D050835:Interferon Regulatory Factors; D019394:Ki-67 Antigen; D000099218:Interferon Regulatory Factor-4