Collection: 01-internacional Database: MEDLINE Main subject: Anus Neoplasms / Papillomaviridae / Carcinoma, Squamous Cell / Mass Screening / Homosexuality, Male Type of study: Diagnostic_studies / Prognostic_studies / Screening_studies Aspects: Patient_preference Limits: Humans / Male Country/Region as subject: America do norte Language: En Journal: Am J Med Year: 2000 Document type: Article Country of publication: