OBJECTIVE(S): HIV-positive individuals have elevated rates of anal squamous cell carcinoma (SCC), and sexually transmitted infections with its causative agent, high-risk human papillomavirus, and other oncoviruses including hepatitis B virus (HBV). HBV infection can cause liver cancer, and has been associated with increased risk of some extra-hepatic cancers including biliary tract cancer, pancreatic cancer, and non-Hodgkin lymphoma. Whether HBV is associated with anal SCC risk is unknown.
DESIGN: Prospective study of anal SCC risk in HIV-positive and -negative men who have sex with men (MSM) in the Multicenter AIDS Cohort Study from 1984-2014.
METHODS: Poisson regression models were used to examine the association between past or current HBV infection (positive tests for HBV core antibodies, surface antigen, and/or DNA) and anal SCC risk.
RESULTS: We observed 53 cases of anal SCC among 5,298 participants with 79,334 person-years follow-up. Among HIV-positive men, past or current HBV infection was associated with anal SCC risk in models adjusted for age, CD4+ cell counts, HAART use, and other risk factors (incidence rate ratio [IRR], 95% confidence interval [CI] 3.15, 1.27-7.82). Additional risk factors included immunological parameters one and six years prior to diagnosis (IRR, 95% CI 2.45, 1.31-4.58 and 2.44, 1.3-4.59 for CD4+ counts <500 cells/μl; 2.43, 1.34-4.42 and 2.77, 1.5-5.11 for CD4:CD8 ratios <0.5, respectively). Among HIV-negative men, IRR for prior HBV and anal SCC risk was similar, but not significant due to small number of cases.
CONCLUSIONS: HIV-positive MSM with prior HBV infection have increased anal SCC risk. This population may benefit from screening.This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0.