Immuno-virological and clinical impacts of treating cancer in patients living with HIV

Abstract

Background: Patients living with HIV (PLHIV) are increasingly being affected by cancer. However, data evaluating the long-term impact of cancer treatment on HIV course are sparse.

Methods: To determine whether anticancer treatments detrimentally impact HIV course, we conducted a retrospective cohort study in seven hospitals in France. Adult PLHIV treated for haematological or solid malignancies were included and compared (1:1) with suitably matched (cancer-free) controls. The primary outcome was the risk of a ≥ 25% reduction in the absolute CD4+ count during follow-up. The risks for virological failure (i.e. a confirmed plasma viral load >50 copies/mL), incidental AIDS-related illnesses and death over time were also assessed. Multivariate Cox proportional-hazards regression analyses were used to identify the outcome predictors.

Results: One-hundred-and-ten patients with cancer and 110 controls were followed for a median of 4.4 years. In a Cox model, the CD4+ depletion was strongly predicted by external radiotherapy (ERT) exposure (HR = 5.1, 95% CI, 3.0-8.6, P < 0.0001) but not by chemotherapy. For patients exposed to ERT, the magnitude of the CD4+ depletion peaked 6 months after their cancer diagnosis (mean CD4+ drop at this time = -283 ± 370 cells/mm(3)). Overall, the cancer patients were also more likely to experience virological failure than the controls (HR = 1.7, 95% CI, 1.1-2.7, P = 0.03). Finally, the incidence of AIDS-related illnesses was similar for both groups.

Conclusions: In PLHIV, cancer treatment increased the risk for prolonged CD4+ depletion and virological failure but had no impact on AIDS-related events when appropriate prophylaxes were implemented.

Keywords: AIDS; ART; CD4+ depletion; virological failure.