Epstein-Barr Virus is Associated With Aggressive Subtypes of Invasive Ductal Carcinoma of Breast (Her۲+/ER- and Triple Negative) and With Nuclear Expression of NFκB p۵۰

Background: A growing body of evidence suggests a possible role for Epstein-Barr virus (EBV) in the pathogenesis of a subset of breast cancers, with many ofthese studies highlighting an increased association between EBV and aggressiveforms of breast carcinoma. This study aimed to further investigate this issue byassessing the possible association between EBV and the Her۲+/ER- and Triplenegative sub types of invasive ductal carcinoma (IDC). Methods: An immunohistochemical marker for EBV (Epstein-Barr virusnuclear antigen ۱ (EBNA۱) clone E۱-۲.۵) was applied to tissue micro arraysections. The tissue micro array's contained ۵۸ cases of Her۲+/ER- IDC, ۵۷ cases oftriple negative IDC and ۶۷ cases of luminal like IDC. Each case was scored aspositive or negative for nuclear expression of EBNA۱ in tumour cells usingstandard light microscopy. Clinical and pathological details where noted for eachcase, as was the nuclear expression of NFκB p۵۰. Results: EBV infection was apparent in ۴۳.۲% of all cases. By subtype EBVwas evident in ۳۱ (۵۷.۴%) Her۲+/ER- cases, ۲۸ (۴۹.۱%) triple negative cases, and۱۴ (۲۴.۱%) luminal like cases; with a significant association being noted betweenthe Her۲+/ER- and triple negative cases and EBV infection (P ۰.۰۰۱). Thisassociation was primarily linked with ER negativity, Her۲ status showed nosignificant association with EBV infection. There were no significant associationswith other clinical and pathological characteristics. Of the ۵۳ cases demonstratingNFκB p۵۰ nuclear staining, ۳۷ (۶۹.۸%) were also infected by EBV (P <۰.۰۰۱). Conclusion: This study provides evidence that EBV is associated withaggressive subtypes of IDC (Her۲+/ER- and triple negative) as well as providingevidence for a link between EBV and NFκB p۵۰ nuclear expression, although thenature of these associations remains unclear.

Keywords:

Epstein-Barr virus , breast cancer , estrogen receptor , Her۲ receptor , nuclear factor κB