The goal of this proposal is to determine features of the immune microenvironment and tumor genetics that drive the aggressive natural history and clinical course of non-small cell lung cancer in people with HIV (PWH). Lung cancer is now the most common NADC and is the leading cause of cancer deaths in PWH. This major burden of disease is further compounded by worse lung cancer outcomes; several large studies including our own have found that lung cancer survival is worse in PWH even after accounting for treatment, suggesting more aggressive cancer behavior. We have identified several unique factors that contribute to the excess risk of lung cancer associated with HIV and also may contribute to tumor behavior. First, we have found that prolonged exposure to low CD4/CD8 ratios, a measure of abnormal immune activation, often precede lung cancer incidence and are associated with a marked (3-fold) independent increase in lung cancer risk in PWH. Second, we have found increased infiltration of CD8 cells in and around HIV associated tumors (including lung cancer), and that paradoxically these cells are often associated with worse outcomes. Third, we have found that increased proportions of circulating T-regulatory (Treg) cells are independently associated with lung cancer risk in PWH, a unique risk factor in this group. The unique immunologic environment coexisting with lung cancer development in PWH even in the setting of well controlled viremia is likely to lead to unique tumor behavior. Furthermore, these disturbances are likely to promote unique tumor evolutionary pressure, thereby spurring greater mutational burden in these tumors. In this study, we will test whether lymphocyte exhaustion, local immunosuppressive and pro-tumor tolerance signaling drive lung cancer development that may explain the excess and poor outcomes of lung cancer associated with HIV infection. We will also evaluate the tumor genetic properties of these tumors, factors that also influence the antigenicity and immune response to these cancers, but also directly impact their behavior. These efforts will generate novel prognostic strategies and improve understanding of the effects of HIV on lung cancer outcomes for a major source of morbidity in HIV+ persons. Our Specific Aims are to: (1) Assess the impact of tumor microenvironment abnormal immune activation, lymphocyte exhaustion, local immunosuppression, and pro-tolerance signaling on clinical outcomes for NSCLC in PWH; (2) Compare the prevalence of NSCLC driver mutations and mutational patterns in PWH and uninfected persons. To accomplish these Aims we will utilize banked biopsy and surgical specimens from PWH and uninfected comparators with well characterized phenotypic data from our biorepository. We will evaluate the banked specimens using cutting-edge mass cytometry imaging technique to characterize the lesional infiltrating and surrounding lymphocytes, lesional epithelial cells and stroma. Then we will sequence NSCLC fro...