Changing patterns of cancer incidence in the early- and late-HAART periods: the Swiss HIV Cohort Study

Abstract

Background: The advent of highly active antiretroviral therapy (HAART) in 1996 led to a decrease in the incidence of Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL), but not of other cancers, among people with HIV or AIDS (PWHA). It also led to marked increases in their life expectancy.

Methods: We conducted a record-linkage study between the Swiss HIV Cohort Study and nine Swiss cantonal cancer registries. In total, 9429 PWHA provided 20,615, 17,690, and 15,410 person-years in the pre-, early-, and late-HAART periods, respectively. Standardised incidence ratios in PWHA vs the general population, as well as age-standardised, and age-specific incidence rates were computed for different periods.

Results: Incidence of KS and NHL decreased by several fold between the pre- and early-HAART periods, and additionally declined from the early- to the late-HAART period. Incidence of cancers of the anus, liver, non-melanomatous skin, and Hodgkin's lymphoma increased in the early- compared with the pre-HAART period, but not during the late-HAART period. The incidence of all non-AIDS-defining cancers (NADCs) combined was similar in all periods, and approximately double that in the general population.

Conclusions: Increases in the incidence of selected NADCs after the introduction of HAART were largely accounted for by the ageing of PWHA.

Figure 1

Incidence rates (standardised by 5-year age group and, when appropriate, sex, based on the age and sex distribution of all people with HIV or AIDS (PWHA) included in this study) and corresponding 95% confidence intervals of all cancers among PWHA by sex or HIV-transmission category and period of cancer diagnosis. MSM, men having sex with men; HET, heterosexual; IDU, intravenous drug user.

Figure 2

Age-specific incidence rates of selected cancers among people with HIV or AIDS (PWHA) and the general population from the same Swiss Cantons (age-standardised as in Figure 1) by period of cancer diagnosis. PY, person-years.