Cytomegalovirus and Epstein-Barr virus in breast cancer.
Findings of polymerase chain reaction (PCR) studies of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) and breast cancer vary, making it difficult to determine whether either, both, or neither virus is causally associated with breast cancer. We investigated CMV and EBV in paired samples of breast cancer and normal breast tissue from 70 women using quantitative PCR. A serum sample from each woman was tested for CMV and EBV IgG. To place our results in context, we reviewed the existing literature and performed a meta-analysis of our results together with previous PCR studies of EBV, CMV, and breast cancer. Of the serology samples, 67 of 70 (96%) were EBV IgG positive and 49 of 70 (70%) were CMV IgG positive. QPCR detected EBV in 24 (34%) of the tumour and 9 (13%) of the paired normal specimens and CMV in 0 (0%) of the tumour and 2 (3%) of the paired normal specimens. Our findings, together with earlier results summarised in the meta-analysis, suggest several possibilities: variable findings may be due to limitations of molecular analyses; 'hit and run' oncogenesis may lead to inconsistent results; one or both viruses has a role at a later stage in breast cancer development; infection with multiple viruses increases breast cancer risk; or neither virus has a role. Future studies should focus on ways to investigate these possibilities, and should include comparisons of breast cancer tissue samples with appropriate normal tissue samples.
Wayne Francis Cancer Epidemiology Research Group, School of Health Sciences, University of Canterbury, Christchurch, New Zealand.
Ann K
AK
Richardson
Mackenzie Cancer Research Group, University of Otago, Christchurch, New Zealand.
Margaret J
MJ
Currie
Mackenzie Cancer Research Group, University of Otago, Christchurch, New Zealand.
Bridget A
BA
Robinson
Mackenzie Cancer Research Group, University of Otago, Christchurch, New Zealand.
Helen
H
Morrin
Mackenzie Cancer Research Group, University of Otago, Christchurch, New Zealand.
Yen
Y
Phung
Biostatistics and Computational Biology Unit, University of Otago, Christchurch, New Zealand.
John F
JF
Pearson
Canterbury Health Laboratories, Christchurch, New Zealand.
Trevor P
TP
Anderson
Wayne Francis Cancer Epidemiology Research Group, School of Health Sciences, University of Canterbury, Christchurch, New Zealand; Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, United States of America; Centre for Public Health Research, Massey University, Wellington, New Zealand.
John D
JD
Potter
Mackenzie Cancer Research Group, University of Otago, Christchurch, New Zealand.
Logan C
LC
Walker
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D001943:Breast Neoplasms / Q000821:virology*; D002277:Carcinoma / Q000821:virology*; D003587:Cytomegalovirus / Q000276:immunology* / Q000302:isolation & purification; D005260:Female; D004854:Herpesvirus 4, Human / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008875:Middle Aged
D000914:Antibodies, Viral; D007074:Immunoglobulin G