VIRUS-ASSOCIATED BREAST CANCER (REVIEW AND METAANALYSIS)

Abstract

The assessment of the etiological role of viruses in the development of breast cancer remains the subject of intense study. This review examines the data on the presence/absence of viral infection in breast cancer tumors and its clinical significance. The reports on the association of breast cancer with three groups of viruses: HMTV (human Mammary Tumor Virus / MMTV-like), Epstein-Barr virus (EBV) and human papillomavirus (HPV) were analyzed. The authors carried out meta-analysis for each type of virus, which demonstrated the association of the viral infection with breast cancer tissue. A meta-analysis of 1389 breast cancer tissue samples and 750 normal breast tissue samples showed a high level of HMTV infection in the breast cancer tissue (30.7%). The relative risk of breast cancer associated with HMTV infection was 16.7 (95% CI: 7.0-39.7, p = 1.69x10-10). For EBV, the meta-analysis of 1131 breast tumor samples and 185 normal breast tissue samples (based on 9 primary studies) showed that the incidence of EBV infection was 30. .4% in tumor breast tissue and 4.3% in normal breast tissue. The relative risk of EBV-associated breast cancer was 3.3 (95% CI: 1.8-5.8, р=0.00006). The meta-analysis of HPV infection included 29 primary studies with 2,446 tumor tissue samples and 1,144 normal tissue samples. The prevalence of HPV in breast cancer samples and in normal tissue samples was 25% and 4.5%, respectively. The relative risk of breast cancer associated with HPV infection was 3.6 (95% CI: 2.3-5.6, p = 2.8x10-8). The data obtained indicate that the studies on the etiological role of HMTV, EBV and HPV in the development of breast cancer are promising.