PARIS, FRANCE. The Epstein-Barr virus (EBV) is a common human herpes virus involved in the development of infectious mononucleosis. The virus has also been associated with Burkitt's lymphoma, Hodgkin's disease, and stomach cancer. Researchers at the French Institute for Health and Medical Research now provide convincing evidence that EBV may be involved in the development of breast cancer. Their study involved 98 women (73 per cent postmenopausal) and two men with previously diagnosed breast cancer. The researchers extracted biopsy specimens of the tumours from all participants as well as 30 samples of tissue adjacent to the tumours and five samples of lymph nodes with metastasis. The DNA of all samples was analyzed using the polymerase chain reaction (PCR), Southern blot analysis, and immunohistochemical staining. The researchers found the Epstein-Barr virus in 51 per cent of the tumour samples, but in only 10 per cent of the samples of adjacent breast tissue. The prevalence of EBV was particularly high in tumours associated with aggressive metastasis (more than three lymph nodes involved); here 72 per cent of all tumours showed the presence of EBV as compared to only 44 per cent of tumours associated with three or less positive nodes. EBV was also detected more frequently in tumours that were negative for steroid hormone receptors; such tumours are associated with more aggressive disease and a poor outcome. The researchers conclude that the Epstein-Barr virus may be implicated in the development of breast cancer particularly the more aggressive forms.
Bonnet, Mathilde, et al. Detection of Epstein-Barr virus in invasive breast cancers. Journal of the National Cancer Institute, Vol. 91, August 18, 1999, pp. 1376-81