Trends in the Incidence of HIV-Related Hematologic Malignancies in the Era of Combination Antiretroviral Therapy and Predictors of HIV-Related Non-Hodgkin's Lymphoma Development and Survival.

Since the introduction of combination antiretroviral therapy (cART), the incidence rates of non-Hodgkin's lymphoma (NHL) and primary central nervous system lymphoma (PCNSL) have declined; however, less is known about the rates of other hematologic malignancies such as Hodgkin lymphoma (HL) and multiple myeloma (MM). We aimed to study changes in the incidence and outcomes of hematologic malignancies (HMs) in the pre- and post-cART eras.

A retrospective analysis of The Ontario HIV Treatment Network Cohort Study (OCS) was performed. The OCS is an ongoing prospective study of HIV-infected adults from 11 sites throughout Ontario, Canada. Incidence rates of HMs were calculated for the pre- (<1997) and post-cART (≥ 1997) eras and compared using Poisson regression analysis. Median survival for each HM was calculated using Kaplan Meier techniques and compared using the logrank test. Predictors of NHL and death from NHL including age, sex, CD4 count, viral load, previous AIDS-defining illness, cART era and duration of HIV infection were evaluated using Cox proportional hazard models. All variables except sex were considered time dependent variables.

The OCS database included 4118 individuals with 41978 person-years of follow up over 28 years (1980-2008). There was no significant difference in the incidence of HM in the pre- and post-cART eras (3.6 versus 4.1 cases per 1000 person-years, p-value=0.49) although incidence of PCNSL trended downward (0.8 versus 0.4 cases per 1000 person-years, p-value=0.13) and incidence of HL trended upward (0.1 versus 0.4 cases per 1000 person-years, p-value=0.08). Those with HL had the longest median survival, followed by NHL and PCNSL (63, 39 and 4 months respectively). Predictors of NHL development included low CD4 count, high viral load and pre-cART era. Predictors of death following NHL diagnosis were low CD4 count, previous AIDS-defining illness and longer duration of HIV infection.

Since the introduction of cART, the overall incidence of HM has not significantly changed in this cohort. However, as fewer individuals in the cART era develop low CD4 counts, high viral loads and AIDS-defining illnesses, reduced incidence of NHL in this cohort and improved survival following NHL may become apparent.

No relevant conflicts of interest to declare.