title: Prognostic Implication of Semi-quantitative Immunohistochemical Assessment of CD20 Expression in Diffuse Large B-Cell Lymphoma.
abstract: BACKGROUND
  Immunohistochemical demonstration of CD20 in diffuse large B-cell lymphoma (DLBCL) is prerequisite not only for the diagnosis but also for assigning patients to rituximab-containing chemotherapy. However, little is known about the impact of abundance of CD20 expression assessed by immunohistochemistry on the clinical outcome of DLBCL. We performed a semi-quantitative immunohistochemical analysis of CD20 expression in DLBCL to examine the prognostic implication of the level of CD20 expression.
  
  
  METHODS
  Pre-treatment diagnostic tissue samples from 48 DLBCL patients who were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen were represented in a tissue microarray and immunostained for CD20. The relative abundance of CD20 expression was semi-quantitatively scored using a web-based ImmunoMembrane plug-in. Receiver operating characteristic curve analysis was used to determine a prognostically relevant cut-off score in order to dichotomize the patients into CD20-high versus CD20-low groups.
  
  
  RESULTS
  The levels of CD20 expression were heterogeneous among the patients, with a wide and linear distribution of scores. Patients in CD20-low group showed significantly poor clinical outcome.
  
  
  CONCLUSIONS
  The levels of CD20 expression in DLBCL are heterogeneous among the patients with DLBCL. A subgroup of the patients with CD20 expression levels below the cut-off score showed poor clinical outcome.
authors.affiliation: Department of Pathology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: Chang Hwan
authors.initials: CH
authors.lastname: Choi
authors.affiliation: Department of Hematology-Oncology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Park
authors.affiliation: Department of Hematology-Oncology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: Joo Han
authors.initials: JH
authors.lastname: Lim
authors.affiliation: Department of Pathology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: Suk Jin
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Pathology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: Lucia
authors.initials: L
authors.lastname: Kim
authors.affiliation: Department of Pathology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: In Suh
authors.initials: IS
authors.lastname: Park
authors.affiliation: Department of Pathology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: Jee Young
authors.initials: JY
authors.lastname: Han
authors.affiliation: Department of Pathology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: Joon Mee
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Pathology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
authors.forename: Young Chae
authors.initials: YC
authors.lastname: Chu
keywords: Antigen, CD20; Immunohistochemistry; Lymphoma, large B-cell; Tissue array analysis