Human Papilloma Virus infection and breast cancer development: Challenging theories and controversies with regard to their potential association

Breast cancer (BC) remains the most frequently diagnosed malignancy among women worldwide. Recognized predisposing factors may be absent in the majority of affected patients, which has aroused a stronger interest in identifying risk parameters that contribute to BC pathogenesis. Human papilloma virus (HPV) infection is strongly associated with malignancies, such as cervical cancer, oropharyngeal cancer and anal cancer. Various surveys have linked HPV to the development of BC. Relevant variations in HPV identification among BC samples may be attributed to differences in study design, the populations involved and the HPV detection techniques applied, which are still controversial with conflicting opinions and results that deny the causative association be- tween HPV infection and BC development. Furthermore, the role of HPV, a potential cause of human BC, has recently received more attention because of the possible restriction of disease progression using an HPV vaccine. The aim of this review was to evaluate both the aspects supporting and those against the theory of BC related to HPV infection. Recent literature has been also assessed in order to provide an update on the current concepts of relevant association.