Prevalence of HPV, EBV, MMTV and SV40 co-infection in women with invasive breast cancer: as a potential new viral etiology

Aim: Breast cancer (BC) is the leading cause of female cancer-related death worldwide. The high incidence of BC has sparked interest in the viral agents role in its development. Identifying co-infection involving potential oncogenic viruses, such as human papillomavirus (HPV), Epstein-Barr virus (EBV), mouse mammary tumor virus (MMTV), and Simian virus 40 (SV40), may improve early detection and treatment strategies of BC. However, the involvement of these viral co-infections in invasive breast cancer (IBC) has not been elucidated. Methods: To investigate this eventual co-infection, screening of viral DNAs isolated from 120 fresh IBC tissue biopsies was performed using a polymerase chain reaction. Statistical analysis were conducted to assess the correlation between viral prevalence and IBC clinicopathological features. Results: Our findings revealed the prevalence of EBV (67.1%), HPV (45.7%), MMTV (72.9%), and SV40 (22.9%) in IBC samples. Co-infection rates were as follows: EBV/HPV (17.14%), EBV/MMTV (22.86%), EBV/SV40 (4.28%), and HPV/MMTV (11.43%). Triple infection with EBV, HPV, and MMTV was observed in 5.71% of cases. Statistically significant associations were identified between: EBV and histological grade, tumour size and stage, and progesterone receptor (PR) and estrogen receptor (ER) status; HPV and histological grade, tumour stage, and PR status; MMTV and histological type, as well as PR and ER status; and SV40 and histological grade and PR status. Conclusions: Although the prevalence of HPV, EBV, MMTV, and SV40 coinfection in Moroccan IBC patients is low, their potential synergistic role in breast carcinogenesis needs to be further investigated, in order to identify new etiological factors for BC.