CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

Conclusions: HIV infection in the elderly is associated with higher risk for many cancers identified as HIV-associated in younger populations. The relative elevation in NHL incidence is notably lower, but this reflects the high frequency in elderly adults of NHL subtypes less strongly associated with HIV. Given the increased risk associated with both aging and HIV, the elderly HIV-infected population has a sizeable absolute risk of cancer, highlighting the need for cancer prevention and screening efforts in this group. 726 Smoking Outweighs HIV-Related Risk Factors for Non–AIDS-Defining Cancers Keri N. Althoff 1 ; Stephen J. Gange 1 ; Chad Achenbach 2 ; Lisa P. Jacobson 1 ; Angel M. Mayor 3 ; Michael J. Silverberg 4 ; Amy Justice 5 ; Richard Moore 6 ;Yuezhou Jing 1 ; Kelly Gebo 6 On behalf of the North American AIDS Cohort Collaboration on Research and Design 1 Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, US; 2 Northwestern University, Feinberg School of Medicine, Chicago, IL, US; 3 Universidad Central del Caribe, Bayamon, US; 4 Kaiser Permanente Northern California, Oakland, CA, US; 5 Veterans Affairs Connecticut Healthcare System and Yale Schools of Medicine and Public Health, New Haven, CT, US; 6 Johns Hopkins University School of Medicine, Baltimore, MD, US Background: The increased burden of non-AIDS-defining cancer (NADC) in HIV-infected adults is likely driven by both HIV-related and other cancer risk factors. The objective of this study is to estimate the population attributable fraction (PAF) for smoking and HIV-related risk factors for NADC, interpreted as the proportion of NADC that could be avoided in HIV-infected adults if all participants had the reference group exposure level. Methods: Adults ( ≥ 18 years) participating in one of 16 contributing cohorts to the North American AIDS Cohort Collaboration on Research and Design who were observed for validated NADC diagnosis from January 1, 2000 to December 31, 2009 were included in this analysis. HIV-related risk factors included CD4 count <200 cells/mm 3 , HIV RNA ≥ 200 copies/mL, and clinical AIDS diagnosis. Hepatitis B (HBV) and C (HCV) infections and smoking were also examined. Data on alcohol use, BMI, and HPV infections were not currently available. Risk factors were measured at study entry, with the exception of time-dependent CD4 count and HIV RNA. Cox proportional hazard models with piecewise constant baseline hazard functions were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals ([,]). The PAFs for the modifiable risk factors of interest were estimated using the methodology described by Laaksonen, et al . Results: Among 39,554 adults who contributed 159,914 person-years, there were 592 incident cancer outcomes distributed as 101 (17%) lung, 96 (16%) anal, 60 (10%) prostate, 54 (9%) Hodgkin, 42 (7%) liver, and 42 (7%) breast cancers. No other cancer type represented more than 5% of the NADC. At baseline, participants who developed NADC were older and had greater proportions with a history of smoking, dyslipidemia, HBV, HCV, and an AIDS diagnosis compared to those without NADC. The PAFs for the variables in the final model can be seen in Figure 1. After excluding lung cancers from the analysis, the PAF for smoking was 39% [23%, 52%].

Poster Abstracts

Figure 1: Population attributable fractions and 95% confidence intervals for smoking and HIV-related risk factors for non-AIDS-defining cancers

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CROI 2015