Human betaretrovirus (HBRV), homologous to mouse mammary tumor virus (MMTV), and human breast cancer: a significant epidemiological association

This meta-analysis suggests strong epidemiological evidence supporting an association between HBRV infection and human breast cancer, and is consistent with a possible etiological role. However, variability in study methodologies and geographic differences warrant further investigation through standardized, large-scale studies to confirm these findings and explore potential mechanisms of viral oncogenesis in breast cancer.