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.