To describe trends in incidence rates of AIDS-defining cancers (ADCs) and non-AIDS-defining cancers (NADCs) during the HIV epidemic and to evaluate predictors, including the impact of antiretroviral therapy, of cancer development.
Retrospective analysis of a multicenter, prospective natural history study including 4,498 HIV-infected U.S. military beneficiaries with 33,486 person-years of follow-up.
Predictors evaluated included demographics, clinical data, time-updated CD4 cell counts, HIV viral loads, and antiretroviral history. Time periods were classified as early pre- (1984-1990), late pre- (1991-1995), early post- (1996-2000), and late post-(2001-2006) HAART eras. Cox proportional hazard models were used to evaluate the association of specific factors with cancer.
Ten percent of HIV-infected persons developed cancer. ADC rates increased between the early and late pre-HAART eras (7.6 and 14.2 cases per 1000 person years) and have since declined from 5.4 to 2.7 in the early and late HAART eras, respectively (p<0.001). Rates of NADCs have risen over the four time periods (2.9, 2.8, 4.2, 6.7, p=0.0004). During the late HAART era, 71% of cancers were NADCs. Predictors for ADCs included low CD4 cell count, non-cancer AIDS diagnosis, and lack of HAART. NADCs were predicted by increasing age, Caucasian race (due to skin cancers), and lack of HAART.
Although the rate of ADCs continues to fall, the rate of NADCs is rising and now accounts for the majority of cancers in HIV-infected persons. The development of NADCs is associated with increasing age among HIV patients. HAART is protective for both ADCs and NADCs.