_:vb629546 _:vb729389 . _:vb645672 . "Anal Canal Carcinoma"^^ . "Malignant"^^ . _:vb748062 _:vb645673 . "A squamous cell carcinoma or less frequently an adenocarcinoma, often associated with human papillomavirus (HPV) infection. Homosexual men are at particular risk. The most important prognostic factors are tumor stage and nodal status.NCI" . _:vb729389 _:vb748061 . "C7489"^^ . "Anal Canal and Perianal Gland CarcinomaSYNCI" . _:vb629546 . "Neoplastic Process"^^ . "Anal_Canal_Carcinoma"^^ . "C0563211"^^ . _:vb645673 . "Anal Canal and Perianal Gland CancerSYNCI" . _:vb729389 . _:vb645672 . _:vb629546 . _:vb748061 _:vb645672 . _:vb645672 . _:vb645673 . . "Anal Canal CarcinomaPTNCI" . _:vb645673 . "Anal Canal CancerSYNCI" . _:vb748061 _:vb748062 . . _:vb748062 . "Anal Canal Carcinoma"^^ .