Increased risk of anal squamous cell carcinoma in HIV-positive men with prior hepatitis B virus infection

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 HIV-negative MSM in the Multicenter AIDS Cohort Study from 1984 to 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 5298 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 3.15, 1.27-7.82]. Additional risk factors included immunological parameters 1 and 6 years prior to diagnosis (IRR, 95% confidence interval 2.45, 1.31-4.58 and 2.44, 1.3-4.59 for CD4(+) cell counts < 500 cells/ml; 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 NS due to small number of cases. Conclusion: HIV-positive MSM with prior HBV infection have increased anal SCC risk. This population may benefit from screening. Copyright (C) 2018 The Author(s). Published by Wolters Kluwer Health, Inc.