Evaluation of the relative frequency of Epstein–Barr virus infection in patients with recurrent breast cancer compared with patients with nonrecurrent breast cancer

The roles of Epstein–Barr virus (EBV) in breast cancer and breast lymphoma by transfecting EBV DNA have been indicated in different studies, but few investigations have been conducted on its roles in recurrence of breast cancer. Here, we aimed to evaluate the roles of EBV in recurrent breast cancer tissue.

This is a cross‑sectional retrospective study that was performed in 2020–2021 in Isfahan on patients with breast cancer. The study population consisted of 30 tissue samples from recurrent breast cancer and 30 samples from nonrecurrent breast cancer. We collected demographic data of patients including age using a checklist. Other collected data were type of cancer, stages of cancer, tumor size in greatest dimension, lymph node involvements, and presence of metastasis. Furthermore, we evaluated all of the pathology samples from both groups for the presence of DNA of EBV and compared the data of both groups.

The DNA of EBV was positive in 8 patients of the relapsed group (26.6%) and 7 patients in the nonrelapsed patients(23.3%). There was no significant difference between two groups regarding positive DNA of EBV (P = 0.39). There were no significant differences between two groups of positive DNA of EBV with and without recurrent breast cancer regarding type of cancer (P = 0.63), stage of cancer (P = 0.19), tumor size in greatest dimension (P = 0.31), mean lymph node involvement(P = 0.27), number of lymph node involvement(P = 0.43), and metastasis(P = 0.69).

EBV might have no significant role in recurrence of breast cancer.