title: Risk factors for anal cancer in persons infected with HIV: a nested case-control study in the Swiss HIV Cohort Study.
abstract: Although persons infected with human immunodeficiency virus (HIV), particularly men who have sex with men, are at excess risk for anal cancer, it has been difficult to disentangle the influences of anal exposure to human papillomavirus (HPV) infection, immunodeficiency, and combined antiretroviral therapy. A case-control study that included 59 anal cancer cases and 295 individually matched controls was nested in the Swiss HIV Cohort Study (1988-2011). In a subset of 41 cases and 114 controls, HPV antibodies were tested. A majority of anal cancer cases (73%) were men who have sex with men. Current smoking was significantly associated with anal cancer (odds ratio (OR) = 2.59, 95% confidence interval (CI): 1.25, 5.34), as were antibodies against L1 (OR = 4.52, 95% CI: 2.00, 10.20) and E6 (OR = ∞, 95% CI: 4.64, ∞) of HPV16, as well as low CD4+ cell counts, whether measured at nadir (OR per 100-cell/μL decrease = 1.53, 95% CI: 1.18, 2.00) or at cancer diagnosis (OR per 100-cell/μL decrease = 1.24, 95% CI: 1.08, 1.42). However, the influence of CD4+ cell counts appeared to be strongest 6-7 years prior to anal cancer diagnosis (OR for <200 vs. ≥500 cells/μL = 14.0, 95% CI: 3.85, 50.9). Smoking cessation and avoidance of even moderate levels of immunosuppression appear to be important in reducing long-term anal cancer risks.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bertisch
authors.forename: Silvia
authors.initials: S
authors.lastname: Franceschi
authors.forename: Mauro
authors.initials: M
authors.lastname: Lise
authors.forename: Pietro
authors.initials: P
authors.lastname: Vernazza
authors.forename: Olivia
authors.initials: O
authors.lastname: Keiser
authors.forename: Franziska
authors.initials: F
authors.lastname: Schöni-Affolter
authors.forename: Christine
authors.initials: C
authors.lastname: Bouchardy
authors.forename: Silvia
authors.initials: S
authors.lastname: Dehler
authors.forename: Fabio
authors.initials: F
authors.lastname: Levi
authors.forename: Gernot
authors.initials: G
authors.lastname: Jundt
authors.forename: Silvia
authors.initials: S
authors.lastname: Ess
authors.forename: Michael
authors.initials: M
authors.lastname: Pawlita
authors.forename: Helen
authors.initials: H
authors.lastname: Kovari
authors.forename: Gilles
authors.initials: G
authors.lastname: Wandeler
authors.forename: Alexandra
authors.initials: A
authors.lastname: Calmy
authors.forename: Matthias
authors.initials: M
authors.lastname: Cavassini
authors.forename: Marcel
authors.initials: M
authors.lastname: Stöckle
authors.forename: Gary
authors.initials: G
authors.lastname: Clifford
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active / Q000009:adverse effects / Q000706:statistics & numerical data*; D001005:Anus Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000821:virology; D018791:CD4 Lymphocyte Count; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology; D018451:Homosexuality, Male / Q000706:statistics & numerical data; D052162:Human papillomavirus 16 / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D016867:Immunocompromised Host; D015994:Incidence; D008297:Male; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000150:complications* / Q000635:transmission / Q000821:virology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000150:complications*; D013557:Switzerland / Q000453:epidemiology
keywords: HIV; anal cancer; case-control study; human papillomavirus; immunodeficiency