Reactivity with A monoclonal antibody to Epstein-Barr virus (EBV) nuclear antigen 1 defines a subset of aggressive breast cancers in the absence of the EBV genome.
Previous studies have suggested that common breast cancers are associated with EBV. We used a highly sensitive quantitative real-time PCR method to screen whole tumor sections of breast cancers for the presence of the EBV genome. EBV DNA was detected in 19 of 92 (21%) tumors, but viral load was very low in positive samples (mean = 1.1 copy EBV/1000 cells, maximum = 7.1 copies EBV/1000 cells). Importantly, quantitative real-time PCR failed to detect the EBV genome in microdissected tumor cells from any case. Using a monoclonal antibody (2B4-1) reactive against the EBV nuclear antigen-1, we noted strong staining of tumor nuclei in a proportion of those breast cancers that had tested negative for the presence of the EBV genome. Because nuclear staining with the 2B4-1 antibody was previously observed more frequently in poor prognosis breast cancers, we examined a larger series of breast cancers with complete clinical follow-up. Strong punctate staining of tumor cell nuclei was observed in 47 of 153 (31%) breast cancers; 2B4-1-positive tumors were significantly more likely to be ER-negative (P < 0.0001), to be of higher grade (P = 0.001) and larger (P = 0.03), to involve more regional lymph nodes (P = 0.01), and to have higher Nottingham Prognostic Index scores (P = 0.0003). Conclusions are: (a) EBV can be regularly detected in whole sections of breast cancers but viral copy number is very low; (b) in these cases, tumor cells do not harbor virus; and (c) reactivity with the monoclonal antibody 2B4-1 is detectable in the absence of the EBV genome and is strongly associated with ER-negative breast tumors and with prognostically unfavorable disease. Additional studies should be directed to the identification of this protein and to elucidation of its role in breast cancer.
Department of Pathology, University of Birmingham, Edgbaston, United Kingdom. p.g.murray@bham.ac.uk
Paul G
PG
Murray
David
D
Lissauer
Jia
J
Junying
Gillian
G
Davies
Sukhjinder
S
Moore
Andrew
A
Bell
Judith
J
Timms
David
D
Rowlands
Christopher
C
McConkey
Gary M
GM
Reynolds
Suk
S
Ghataura
David
D
England
Rebecca
R
Caroll
Lawrence S
LS
Young
D000911:Antibodies, Monoclonal / Q000737:chemistry*; D001943:Breast Neoplasms / Q000473:pathology / Q000821:virology*; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology*; D005260:Female; D016679:Genome, Viral; D004854:Herpesvirus 4, Human / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D019562:Viral Load
D000911:Antibodies, Monoclonal; D019309:Epstein-Barr Virus Nuclear Antigens