Incidence and trends in Kaposi's sarcoma in the era of effective antiretroviral therapy

Objective: To evaluate the impact of antiretroviral and antiherpesvirus the rapies on the incidence of KS and assess trends in incidence of Kaposi's sa rcoma (KS) in a large multicenter HIV/AIDS surveillance system between 1990 and 1998. Methods: Incidence was calculated per 100 person-years (py); the effects of therapies on risk for KS were calculated by using multivariate Poisson reg ression controlling for gender? race/ethnicity, age, HN exposure mode, CD4( +) cell count, and calendar year. Antiretroviral therapy was defined as mon otherapy, dual therapy, or triple therapy (95% of triple therapy regimens c ontained a protease inhibitor). Acyclovir, ganciclovir, and foscarnet were the antiherpesvirus therapies evaluated. Results: There were 37,303 HIV-infected people in the study contributing 70 ,238 py. Those prescribed triple antiretroviral therapy had a 50% reduction in the incidence of KS (95% confidence interval, 20%-70%) compared with th ose who were not prescribed antiretroviral therapy and there was a reductio n in risk for KS among persons prescribed foscarnet (p = .05). Overall, KS incidence declined an estimated 8.8% per year (observed incidence 4.1 per 1 00 py in 1990 to 0.7 per 100 py in 1998; p < .001). Conclusion: Incidence of KS is declining in this large U.S. population and map continue to decline as new, more effective antiretroviral agents are de veloped and used widely.