Incidence of cancer and overall risk of mortality in individuals treated with raltegravir-based and non-raltegravir-based combination antiretroviral therapy regimens

Abstract

Objectives: There are currently few data on the long-term risk of cancer and death in individuals taking raltegravir (RAL). The aim of this analysis was to evaluate whether there is evidence for an association.

Methods: The EuroSIDA cohort was divided into three groups: those starting RAL-based combination antiretroviral therapy (cART) on or after 21 December 2007 (RAL); a historical cohort (HIST) of individuals adding a new antiretroviral (ARV) drug (not RAL) to their cART between 1 January 2005 and 20 December 2007, and a concurrent cohort (CONC) of individuals adding a new ARV drug (not RAL) to their cART on or after 21 December 2007. Baseline characteristics were compared using logistic regression. The incidences of newly diagnosed malignancies and death were compared using Poisson regression.

Results: The RAL cohort included 1470 individuals [with 4058 person-years of follow-up (PYFU)] compared with 3787 (4472 PYFU) and 4467 (10 691 PYFU) in the HIST and CONC cohorts, respectively. The prevalence of non-AIDS-related malignancies prior to baseline tended to be higher in the RAL cohort vs. the HIST cohort [adjusted odds ratio (aOR) 1.31; 95% confidence interval (CI) 0.95-1.80] and vs. the CONC cohort (aOR 1.89; 95% CI 1.37-2.61). In intention-to-treat (ITT) analysis (events: RAL, 50; HIST, 45; CONC, 127), the incidence of all new malignancies was 1.11 (95% CI 0.84-1.46) per 100 PYFU in the RAL cohort vs. 1.20 (95% CI 0.90-1.61) and 0.83 (95% CI 0.70-0.99) in the HIST and CONC cohorts, respectively. After adjustment, there was no evidence for a difference in the risk of malignancies [adjusted rate ratio (RR) 0.73; 95% CI 0.47-1.14 for RALvs. HIST; RR 0.95; 95% CI 0.65-1.39 for RALvs. CONC] or mortality (adjusted RR 0.87; 95% CI 0.53-1.43 for RALvs. HIST; RR 1.14; 95% CI 0.76-1.72 for RALvs. CONC).

Conclusions: We found no evidence for an oncogenic risk or poorer survival associated with using RAL compared with control groups.

Keywords: Raltegravir; observational treatment comparison; propensity scores; risk of cancer; survival.

Figure 1

Patients included in the analysis in the raltegravir (RAL), historical and concurrent cohorts. In order to obtain the total number of patients in each cohort, it is sufficient to add the figures in the corresponding boxes, as follows. (1) The RAL cohort: 456 (historical patients who switched to RAL over follow‐up) + 302 (concurrent patients who switched to RAL) + 712 (patients originally included in the RAL cohort) = 1470. (2) The historical cohort: 3787 (patients originally allocated to this group). The concurrent cohort: 3472 (patients originally allocated to this group) + 995 (historical patients who switched to the concurrent cohort over follow‐up) = 4467. PYFU, person‐years of follow‐up.