RESUMO
The role of Epstein-Barr virus (EBV) in the pathogenesis of breast cancer is still unclear, although a growing body of evidence supports a link. The aim of this study was to investigate if EBV infection was more prevalent in invasive ductal carcinoma or invasive lobular carcinoma. An immunohistochemical marker for EBV (Epstein-Barr virus nuclear antigen 1 (EBNA1) clone E1-2.5) was applied to a tissue micro array section. The tissue micro array contained 80 cases of invasive ductal carcinoma, and 80 cases of invasive lobular carcinoma. Each case was scored as positive or negative for nuclear expression of EBNA1 in tumor cells using standard light microscopy. EBNA1 staining was evident in the tumor cells of 63 cases (39.4% of tumor cases). By tumor type (ductal/lobular) EBV infection was noted in 34 (42.5%) cases of invasive ductal carcinoma and 29 (36.2%) cases of invasive lobular carcinoma, this difference was not found to be significant (P=0.518). This study indicates that EBV infection is equally distributed across the ductal and lobular tumor types.