Men who have sex with men are at risk for transmission of HPV. HPV is known to cause anal cancer. A study was performed to examine the effectiveness of an HPV vaccine (Gardasil®) in preventing the changes that lead up to anal cancer. Prior to the development of cancer, there are changes that occur in the cells infected with HPV. These changes are visible in the way the tissue looks and behaves. The changes lead to new growth of affected cells and result in intraepithelial neoplasia (intra=within, epithelial refers to the cells lining the surface of organs, neo=new, plasia=growth).
In the study, the vaccine was shown to reduce the development of these changes. It is likely therefore, that the vaccine also protects against the development of anal cancer.