Second Primary Cancers in People With HIV/AIDS: A National Data Linkage Study of Incidence and Risk Factors.

Background: Evidence regarding the characteristics of second primary cancer (SPC) in people living with HIV (PLWHIV) is limited.

Setting: We performed a national population-based data linkage study to determine the incidence and risk factors of SPC in PLWHIV in Australia between 1982 and 2012.

Methods: 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.

Results: Of 29,383 individuals diagnosed with HIV, 3123 individuals 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).

Conclusions: The risk of SPC in PLWHIV in Australia remains high, with a temporal increase observed in non-infection-related cancer, likely due to aging of the population. Optimal screening and prevention strategies for SPC in PLWHIV are increasingly important.