CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

Results: The median nadir CD4 cell count of 6,411 MSM in the SHCS increased from 112 cells/μl in 1980-1999 to 394 cells/μl after 2010. Predicted cancer incidence increased to a maximum of 78.7/100,000 person-years in 2010 and has since stabilized. Model estimates up to 2014 are consistent with observed anal cancer incidence in the SHCS. By 2030, incidence will decrease to 58.9/100,000 person-years in the stable scenario, and to 52/100,000 in the 100% cART coverage scenario. Treating patients with electrocautery after yearly anoscopy decreased anal cancer incidence by 37.9%, after yearly cytology by 30.9% and after CD4-dependent anoscopy by 13% (Figure 1). To prevent one anal cancer case 3817 screening tests were needed in the yearly anoscopy strategy, 4684 in the yearly cytology strategy and 242 in the CD4-dependent strategy. Conclusion: Yearly anoscopy leads to the most pronounced decrease in anal cancer incidence and CD4 dependent anoscopy results in most anal cancers prevented per screening test. Expanding ART will have only a modest effect.

Poster and Themed Discussion Abstracts

597 PREVALENCE OF HPV TYPES COVERED BY CURRENT VACCINES IN HIV-INFECTED MEN, SUN STUDY Pragna Patel 1 , Tim Bush 1 , Lois Conley 1 , Elizabeth Unger 1 , Teresa Darragh 2 , Keith Henry 3 , Gerome Escota 4 , Joel Palefsky 2 , John T. Brooks 1 , Erna M. Kojic 5 1 CDC, Atlanta, GA, USA, 2 Univ of California San Francisco, San Francisco, CA, USA, 3 Hennepin County Med Cntr, Minneapolis, MN, USA, 4 Washington Univ, St. Louis, MO, USA, 5 Brown Univ, Providence, RI, USA Background: High-risk anal HPV infection is prevalent among HIV-infected men; but the proportion infected with types covered by current HPV vaccines and association with abnormal cytology have not been well characterized. Methods: The SUN Study was a prospective cohort study of HIV-infected patients receiving care at 7 HIV clinics in 4 US cities. Patients were enrolled from 2004 to 2006. At baseline, providers collected separate anal swabs for HPV detection and cytopathologic examination. We examined the prevalence of the 7 high-risk (HR)-HPV types covered by the nonavalent (9v) HPV vaccine (16, 18, 31, 33, 45, 52, and 58) and associated abnormal cytology (atypical squamous cells of undetermined significance or worse) to assess the impact of the 9v-HPV vaccine. Results: The characteristics of men who have sex with men (MSM, n=403) and men who have sex with women (MSW, n= 96) were similar: median age 42 years, prescribed antiretroviral therapy (78% and 81% respectively), median CD4 cell count (454 cells/mm3 and 379 cells/mm3), CD4 counts >200 cells/mm3 (90% and 83%) and undetectable viral load (74% and 75%). The baseline prevalence of any 9vHR-HPV type in the anus among MSM and MSWwas 74% and 32% and of any 5 types other than HPV 16 or 18 was 23% and 15%, respectively. Among MSM and MSWwith prevalent 9vHR-HPV types, 63% and 44% had abnormal anal cytology, respectively. Among 368 MSMwith adequate anal cytology, abnormal cytology was detected in 206 (56%) MSM and correlated with the presence of any 9vHR-HPV (relative risk [RR] = 1.8 95% CI: 1.3-2.3 p < 0.001) and with > 1 9v HR-HPV types (RR = 1.5, 95% CI: 1.3-1.9 p < 0.001). Among 87 MSW, abnormal anal cytology was detected in 17 (20%) and correlated with the presence of any 9vHR-HPV (RR = 5.3 95% CI: 2.1-13.6 p < 0.001) and with > 1 HR-HPV-9v types (RR = 5.4, 95% CI: 2.7-10.6, p < 0.001). Among MSM and MSW, sensitivity of anal 9vHR HPV detection for the presence of anal cytologic abnormalities was good (83 (78-88)% and 71 (44-90)%, respectively). Specificity was poor among MSM (38 (30-46)%) but good among MSW (79 (67-87)% ). Conclusion: In this contemporary cohort of HIV-infected men, the prevalence of 7 high risk HPV types in the nonavalent vaccine was high and correlated with the presence of cytologic abnormalities. Among MSW, HPV detection may be an initial screening step and the 9v-HPV vaccine may offer substantial prevention benefit. 598 EARLIER VERSUS DELAYED ANTIRETROVIRAL THERAPY INITIATION AND RISK OF CANCER Michael J. Silverberg 1 , Wendy Leyden 1 , Haiqun Lin 2 , Li Qin 2 , Chad J. Achenbach 3 , Gysamber D’Souza 4 , Eric A. Engels 5 , Charles Rabkin 5 , Keri N. Althoff 4 , Romain Neugebauer 1 1 Kaiser Permanente, Oakland, CA, USA, 2 Yale Univ, New Haven, CT, USA, 3 Northwestern Univ, Chicago, IL, USA, 4 Johns Hopkins Univ, Baltimore, MD, USA, 5 NCI, Rockville, MD, USA Background: Cohort and trials evaluating mortality and AIDS events informed guidelines for immediate combination antiretroviral therapy (ART) for all HIV patients. Studies with extended follow-up are needed to evaluate effectiveness of earlier ART on rare events such as cancer. Methods: Cohort study of ART-naïve, AIDS-free, HIV+ adults followed between 1996 and 2009 in the North American AIDS Cohort Collaboration on Research and Design. Subjects were followed from first CD4 of 350-500 cells/μl (baseline) until incident cancer, death, lost-to-follow-up or 2009. Cancers were confirmed by chart review or cancer registry linkage and grouped as: any cancer, virus-unrelated and virus-related non-AIDS-defining cancers (NADC), and AIDS-defining cancers (ADC) (defined in Table footnote). We compared cancer risk among individuals with earlier ART initiation (start ART within 6 months of baseline) with those who delayed ART initiation (no ART, or start ART after 6 months). We used marginal structural modeling with inverse probability weighting to account for time-dependent confounding and informative right-censoring (see variables in Table footnote). Primary results emulated an intention-to-treat randomized trial; we also emulated a per-protocol trial, by accounting for ART discontinuation. Results: A total of 10,434 HIV-infected individuals contributed >44,000 person-years. Participants were 84%men, 46%white, 43% black, with mean age at baseline of 39 years. The most common cancers were: Kaposi sarcoma (n=67) and non-Hodgkin’s lymphoma (n=66) among ADC (n=135); lung (n=45) and prostate cancer (n=40) among virus-unrelated NADC (n=198); and Hodgkin lymphoma (n=15), anal (n=13) and liver cancer (n=13) among virus-related NADC (n=45). Earlier ART constituted 27% of contributed person-time and delayed ART constituted 73% of person-time. Earlier ART initiators had higher median CD4 than late initiators (405 vs. 323 cells/μl). In adjusted intention-to-

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