Risk factors for AIDS-defining and non AIDS-defining cancers

Two oral presentations, one from France and one from Germany, presented cohort data on risk factor for cancers in one of the first oral presentation sessions.

Bruyand presented an analysis of the impact of CD4 count, viral load and duration of immunodeficiency and viraemia on risk of 109 AIDS-defining and 142 non AIDS-defining cancer diagnoses in 4194 patients followed in the French Aquitanine cohort from 1998-2006. [1]

For AIDS-defining cancers, a higher incidence (relative risk) was independently associated with longer time (per year of exposure) with detectable viraemia >500 copies/mL (1.20, 95%CI 1.10-1.31) and CD4 count <200 cells/mm3 (1.35, 95%CI 1.20-1.53). Duration of exposure to combination therapy had a reduced risk (0.82, 95%CI 0.74-0.91). All associations were statistically significant with a p-value <0.001.

The group also reported an association with CD4 counts and non AIDS-defining cancers. Higher incidence was associated with length of time with CD4 <200 cells/mm3 (RR1.16, 95%CI 1.03-1.30; p=0.01) or duration with <500 cells/mm3 (1.11, 95%CI 1.01-1.22, p=0.02) and a lower incidence was associated with female gender (0.58, 95%CI 0.37-0.92, p=0.02). No association was found between viral load or use of treatment for non-AIDS defining cancers.

In the German study, Alexander Zoufaly presented data collected prospectively and retrospectively from 6,458 patients on three-drug HAART being followed in the Clinsurv cohort. [2]

They identified 94 lymphomas (78 AIDS-related NHL and 16 primary CNS) during 28,125 years of follow-up (incidence 3.3/1000 patient years).

Multivariate regression analysis identified MSM (1.86, 95%CI 1.19-2.90), age/10 years (1.40, 95%CI 1.17-1.68), CD4 count <200 cells/mm3 (3.64, 95%CI 2.08-6.40) or CD4 200-350 cells/mm3 (3.08, 95%CI 1.74-5.73) and ongoing viraemia (at least 75% viral load measurements >500 copies/mL), (HR 3.68, 95%CI 2.17-5.35) as increased risk factors (hazard ratio, HR all p<0.001).

When primary CNS lymphoma was analysed separately, there was a stronger effect of CD4 <200 cells/mm3 and less impact of ongoing viraemia.

Comment

These studies add further results to support the growing interest in use of earlier treatment to increase and/or maintain patients CD4 counts >500 copies/mL, and the particular importance of suppressed viraemia, to reduce long-term risk of serious AIDS and non-AIDS events can be reduced.

These oral presentations are available to view online from the conference website (Monday 4 February).