Grant: Doctoral Research Award : Priority Announcement - HIV/AIDS

Background: Cancer has been a major feature of the HIV epidemic, with Kaposi sarcoma and non-Hodgkin lymphoma being the first reported manifestation of AIDS-defining cancers. With the arrival of antiretroviral therapy (ART), HIV has become a chronic disease and studies have shown an increase in non-AIDS defining cancers. Additionally, people living with HIV have a higher risk of developing cancer than the general population. There are 75,500 Canadians living with HIV, with the highest proportion in Ontario. In Canada, there is a lack of research assessing the cancer burden and the effect of ART on cancer risk in people living with HIV. Objectives: 1) Determine the incidence and prevalence of site-specific cancers in adults living with HIV in Ontario between 1995 to 2016; 2) Determine whether specific ART regimens show protective cancer effects; and 3) Quantify the extent to which cumulative exposure to ART lowers the risk of infection-related cancers via controlled viremia and improved immune function. Methods: Study objectives will be achieved using data from Institute for Clinical Evaluative Sciences, Ontario Cancer Registry, Ontario HIV Treatment Network Cohort study, and Canadian HIV Observational Cohort Collaboration. We will calculate incidence rates of site-specific cancers after HIV diagnosis using count modelling techniques. Period prevalence before HIV diagnosis, at HIV diagnosis, and short-term and long-term ART exposure will be calculated. We will quantify relationships between ART use, cancer risk, immune suppression, viremia, demographic, socio-economic and behavioural factors using mediation analysis techniques. Significance: This study will bring forward the need for comprehensive HIV care and cancer control. By understanding the cancer burden and the additional hardships of this key population, medical practice and policies can be adapted to offer better long-term care, plan for resource allocation, and optimize treatment to improve health outcomes.