RESUMO
BACKGROUND: Inflammatory breast cancer (IBC) is the most lethal form of breast cancer. Multiple viral infections in IBC tissues were found to be associated with disease pathogenesis. OBJECTIVE: The aim of the present study was to correlate the incidence of viral DNA with breast cancer progression. MATERIALS AND METHODS: Overall, 135 women diagnosed with breast cancer were enrolled in this study. Using polymerase chain reaction and sequencing assays, we determined the incidence of human papillomavirus types 16 and 18 (HPV-16 and -18), human cytomegalovirus (HCMV), Epstein-Barr virus, human herpes simplex virus type 1 and 2, and human herpes virus type 8 (HHV-8) in breast carcinoma tissue biopsies. We also assessed the expression of the cell proliferation marker Ki-67 by immunohistochemistry in association with the incidence of viral DNA. RESULTS: HCMV and HPV-16 were the most detected viral DNAs in breast carcinoma tissues; however, the frequency of HCMV and HHV-8 DNA were significantly higher in IBC than non-IBC tissues. Moreover, the prevalence of multiple viral DNAs was higher in IBC than non-IBC tissues. The incidence of multiple viral DNAs positively correlates with tumor size and number of metastatic lymph nodes in both non-IBC and IBC patients. The expression of Ki-67 was found to be significantly higher in both non-IBC and IBC tissues in which multiple viral DNAs were detected. CONCLUSIONS: The incidence of multiple viral DNAs in IBC tissues was higher compared with non-IBC tissues. The present results suggest the possibility of a functional relationship between the presence of multiple viral DNAs and disease pathogenesis.