29. Anal cancer trends in Puerto Rico (PR) from 1985 to 2005: impact of HIV status

Abstract

Background PR is one of the US jurisdictions with the highest burden of HIV/AIDS. We describe the proportion of HIV+ anal cancer cases in PR and the impact of HIV status on anal cancer incidence trends, by sex and age. Methods: The PR Central Cancer Registry (PRCCR) and the PR AIDS Surveillance Program databases were linked using a probabilistic linkage algorithm with Link Plus v.2.0 software. The proportion of anal cancer cases with and without HIV in PR were calculated. Temporal trends (1985–2005) in the incidence rates (standardised US 2000 population) of anal cancer (overall and after exclusion of HIV+ cancer cases) were calculated through annual per cent changes (APC) and 95% confidence intervals (CIs), using a Joinpoint log-linear model. Results: From 1985 to 2005, 736 cases of anal cancer were diagnosed in PR; 26 cases were HIV+. While most anal cancer patients were female (70.8%), the proportion of HIV+ patients was higher in males (11.4%) than females (0.77%). In men, incidence increased significantly (APC = 3.23, P < 0.05) when HIV+ cases were considered; the increase was reduced (APC = 0.97) when these were excluded (P > 0.05). In females, incidence increased (APC = 2.01) when HIV+ cases were considered, whereas the increase was reduced (APC = 0.85) when these were excluded; these increases were non-significant (P > 0.05). Conclusions: Consistent with data from the US, the increasing anal cancer incidence rates in PR were strongly influenced by the HIV epidemic in males but were independent of HIV infection in females.