Abstract LB-160: Incidence of non-AIDS-defining cancers over time in the post-ART era
Authors: Joyce Brian Thomas , Hibler Elizabeth , Matthews Christopher , Moore Richard , Eron Joseph , Mayer Kenneth , Kitahata Mari , Saag Michael , Hou Lifang , Achenbach Chad 
Published: August 2018

Background: In the current era of potent antiretroviral therapy (ART), complications and mortality from HIV/AIDS have declined dramatically. ART increasingly allows persons with HIV-infection (PWH) to live longer, but also increases lifetime risk of age-associated chronic diseases such as cancer. Furthermore, the interplay of HIV, immune dysfunction, ART use, aging, and other traditional chronic disease risk factors is under-studied in the context of specific non-AIDS-defining cancers (NADCs). These cancers represent a public health problem that will grow increasingly urgent as HIV-infected individuals age. Descriptive epidemiology of these cancers (compared to Kaposi's sarcoma [KS] and non-Hodgkin's lymphoma [NHL], the most common AIDS-defining cancers [ADCs]), and its changes with the evolution of ART over time, are necessary to address this issue.

Methods: This study used longitudinally collected data from the Centers for AIDS Research (CFAR) Network of Integrated Clinical Systems (CNICS) which captures clinical, sociodemographic, and behavioral data on over 32,000 PWH in care at eight US treatment sites. We included patients who enrolled in CNICS from 2000 through 2014, were not diagnosed with cancer prior to enrollment, and were followed at a CNICS site for at least 180 days. We used linear regression to calculate cancer type-specific time trends, and poisson regression to calculate incidence densities for all cancers, NADCs, and ADCs. Poisson models were adjusted for: age in 2000 (study baseline), nadir CD4 count, any ART use, and hepatitis C virus co-infection. Age and nadir CD4 were standardized to the population mean prior to Poisson regression.

Results: We observed significant changes over time in the incidence rates of colorectal, oropharyngeal, and prostate cancers as well as KS, NHL, and melanoma. From 2000-2014 we observed increases in the incidence densities of colorectal (10.4 to 38.6 cases per 100,000 person-years), oropharyngeal (10.4 to 29.0), and prostate cancers (10.4 to 87.1). Over the same period, we observed decreases in the incidence densities of KS (251.5 to 68.2 cases per 100,000 person-years) and NHL (250.5 to 126.1). The adjusted all-cancer incidence density decreased from 728.6.3 (per 100,000 person-years) in 2000-1 to 518.1 in 2013-4. For ADCs the adjusted incidence density decreased from 224.2 in 2000-1 to 115.5 in 2013-4, while for NADCs the adjusted incidence density increased from 286.7 in 2000-1 to 358.6 in 2013-4.

Conclusion: Changes in the incidence densities of NADCs from 2000-2014 reflect the increasing efficacy of ART. PWH are living longer, with reduced incidence of AIDS-defining cancers and increased incidence of age-related NADCs such as colorectal and prostate cancer. These findings support the continued need to study cancer among PWH to better understand their unique risk factors, including the potential influence of immune recovery and ART on specific NADC risk.

Citation Format: Brian Thomas Joyce, Elizabeth Hibler, Christopher Matthews, Richard Moore, Joseph Eron, Kenneth Mayer, Mari Kitahata, Michael Saag, Lifang Hou, Chad Achenbach. Incidence of non-AIDS-defining cancers over time in the post-ART era [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-160.