Differential impact of combination antiretroviral therapy in preventing Kaposi's sarcoma with and without visceral involvement

Purpose To study the impact of different potent combined antiretroviral treatment (CART) on the incidence of HIV-associated Kaposi's sarcoma (KS) with and without visceral involvement. Patients and Methods Patients were selected from the French Hospital Database on HIV, a large hospital cohort. The risk of KS was estimated by using Cox proportional hazards models adjusting for age, the CD4 cell nadir, the HIV exposure category, prior AIDS, CART, and the type of CART regimen. CART regimens were distinguished according to whether they contained protease inhibitor (PI), non-nucleoside analog (NNRTI), both, or only nucleoside analog (NRTI). Separate analyzes were conducted according to the initial visceral involvement of KS. Results Among the 54,999 patients included in this study (182,756 person-years of follow-up), 1,634 patients were diagnosed with KS during follow-up, of whom 421 had visceral involvement at diagnosis. The KS incidence rate fell from 32 per 1,000 person-years in 1993 to 1994 to 3 per 1,000 person-years after 1999. PI-containing and NNRTI-containing CART regimens were associated with similar reductions in the risk of KS (hazard ratio, 0.68; 95%Cl, 0.61 to 0.75; HR, 0.62; 95% Cl, 0.54 to 0.71, respectively). The risk of visceral KS fell more strongly than the risk of cutaneous KS > 50% and < 30%, respectively). Conclusion The incidence of KS, and especially visceral KS, has fallen sharply since the advent of CART. This effect is likely due to immune restoration rather than to a specific effect on the tumoral process, as PI-containing and NNRTI-containing regimens had similar preventive efficacy.