328. Kaposi Sarcoma in High Population ART Utilization Setting: An Observational Study in Botswana.

Background Despite population antiretroviral treatment (ART) utilization exceeding UNAIDS 90-90-90 targets, Kaposi sarcoma (KS) remains one of the most prevalent malignancies in Botswana. We sought to examine the characteristics and outcomes of KS in the context of high ART utilization. Methods Consenting patients at one of four oncology centers for KS treatment were enrolled prospectively (October 2010 to March 2019) and followed quarterly for 5 years. Survival was estimated using Kaplan–Meier estimator and predictors assessed with Cox proportional hazards modeling. Results A total of 408 KS patients were enrolled and of those, 396 (97%) were HIV-positive and included in analyses. Median age at diagnosis was 40 years (IQR: 34.1, 46.7) and 247 patients (62%) were male. The median CD4 cell count at the time of KS diagnosis was 253 cells/mL (IQR: 134, 364) and 279 (73%) were receiving ART at the time of KS diagnosis. Among those on ART, the median duration of ART prior to KS diagnosis was 11.9 months (IQR: 2.7, 46.7). The proportion receiving ART prior to KS increased during the surveillance period from 58% to 80% (P < 0.001). Of the 248 (62.6%) patients with recent measurement, 91% had HIV-1 RNA < 1000 copies/mL. Five-year overall survival was 73% (95% CI 68–78%). In multivariable analysis, Female sex and higher income were associated with improved survival, but not age or CD4 cell count. The duration of ART was significantly associated with survival (P = 0.02), with improved survival for individuals on ART < 6 months compared with longer ART (HR 0.54; 95% CI 0.29–0.98). The incidence of KS cases declined by nearly 50%, but has remained relatively stable since 2015. Conclusion Survival rates in this cohort were comparable to other KS cohorts. While KS treatment initially declined with ART expansion, KS remains a significant disease burden in Botswana with 80% of cases occurring among individuals receiving ART. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]