Second primary cancers in people with HIV/AIDS: a national data linkage study of incidence and risk factors.

Abstract

The evidence regarding the characteristics of second primary cancer (SPC) in people living with HIV (PLWHIV) is limited. We performed a national population-based data linkage study to determine the incidence and risk factors for SPC in PLWHIV in Australia between 1982 and 2012. We conducted a probabilistic data linkage study to compare the incidence of SPC over time, defined using HIV treatment eras, for SPCs related to oncogenic viral infection in comparison with non-infection related SPCs. Risk factors considered included age at diagnosis of cancer, sex, HIV exposure modality and CD4+ count. Of 29,383 individuals diagnosed with HIV, 3,123 who developed a first primary cancer were included in the analysis. Among them, 229 cases of SPC were identified across 27,398 person years of follow-up. The most common SPCs were non-Hodgkin lymphomas (n=71, 31%). The incidence of SPC overall did not change over time, however there was an increase in individuals diagnosed with HIV in later eras (p-trend=0.001). The incidence of non-infection related SPC increased over time and was associated with older age (p-trend=0.005) and the acquisition of HIV in later eras (p-trend <0.001). Conversely, the incidence of infection-related SPC decreased (p-trend <0.001), but this was no longer significant after adjustment for age (p-trend=0.14). The risk of SPC in PLWHIV in Australia remains high, with a temporal increase observed in non-infection related cancer, likely due to ageing of the population. Optimal screening and prevention strategies for SPC in PLWHIV are increasingly important.