Combination antiretroviral therapy and incidence of AIDS-related malignancies

We evaluated recent trends in the incidence of AIDS-related malignancies us ing Cox proportional hazards analysis in 622 men with well-characterized da tes of HIV seroconversion in the San Francisco City Clinic cohort. By the e nd of 1996. 182 men had been diagnosed with Kaposi's sarcoma (KS), and 45 m en had been diagnosed with lymphoma. The incidence of KS dropped from 3.5 t o 0 per 100 person-years between 1993 through 1995 and 1996 (p = .07), wher eas lymphoma incidence remained stable between these periods (1.4-1.8, p = .2). Combination antiretroviral therapy increased from 13% to 23% in 1993 t hrough 1995 to 49% in 1996 and 79% in 1997. The decline in KS cannot be exp lained by earlier declines in HIV incidence, and concurrent increases in an tiretroviral therapy suggests that control of viral replication may lead to a direct or indirect effect on KS pathogenesis. Failure to see such a tren d for AIDS-related lymphoma may reflect inadequate follow-up time after wid espread use of therapy or a need to treat earlier in the course of HIV infe ction to prevent HIV-associated lymphomagenesis.