Background: Invasive ductal and lobular carcinomas (IDC and ILC) are the most common histological types of breast cancer. Clinical follow-up data and metastatic patterns suggest that the development and progression of these tumors are different. The aim of our study was to identify gene expression profiles of IDC and ILC in relation to normal breast epithelial cells.

The Epstein-Barr virus (EBV) is associated with the development of several human tumors, including Hodgkin's lymphoma (HL) and EBV-positive undifferentiated nasopharyngeal carcinoma (NPC).1 In HL, the malignant Hodgkin's and Reed-Sternberg (HRS) cells constitute only a minority of the total tumor mass, and are surrounded by variable proportions of nonmalignant reactive cells. In approximately onehalf of HL, EBV can be detected in HRS cells, where the virus expresses a limited subset of genes; these include the Epstein-Barr nuclear antigen-1 (EBNA1) and the latent membrane proteins, LMP1 and LMP2.2 Although EBV-specific cytotoxic T cells (CTLs) can be detected in HL and NPC and have been shown to kill LMP1-and LMP2-expressing cells in vitro, they are unable to eliminate EBV-infected tumor cells in vivo. [3][4][5] This failure may be because of increased recruitment of regulatory T cells

The Epstein-Barr virus (EBV) has been linked to the development of a variety of human malignancies, including Burkitt's lymphoma, Hodgkin's disease, nasopharyngeal carcinoma, some T cell lymphomas, post-transplant lymphoproliferative disease, and more recently, certain cancers of the stomach and smooth muscle. This review summarises these associations and in particular the role of the viral latent genes in the transformation process. (J Clin Pathol: Mol Pathol 1999;52:307-322)