HIV and Cancer Survival

Abstract

Evidence exists for an association between HIV and multiple AIDS-defining and non-AIDS-defining malignancies, resulting in a growing cancer burden that is increasingly recognized to impact resource-limited countries. Despite the consistent evidence for an association between immunosuppression and cancer risk, little is known about how HIV impacts cancer survival. We therefore investigated the role of HIV on survival after a cancer diagnosis in a retrospective cohort from Uganda (N=802). Cancer patients that resided in Kyadondo County, were >18 years of age, and were diagnosed from 2003-2010 with one of the following cancers were eligible: breast cancer (N=220), cervical cancer (N=316), Non-Hodgkin lymphoma (N=134), Hodgkin lymphoma (N=63), and esophageal cancer (N=69). Cancer patients were classified as HIV-positive based on a positive HIV antibody lab test, HIV-positive medical history in the clinical notes, or an HIV clinic referral letter. The primary outcome, vital status at 1 year following primary cancer diagnosis, was abstracted from the patient medical record or determined through database linkages to the national hospice system. Cox proportional hazards regression was utilized to evaluate the association between HIV status at the time of primary cancer diagnosis and 1-year case-fatality. HIV-positive cancer patients in Uganda experienced a more than two-fold increase in case fatality during the year following cancer diagnosis compared to HIV-negative patients (HR=2.32; 95% CI 1.64-3.29). This marked inverse association between HIV infection and cancer survival was consistently observed for both cancers with (HR=1.61; 95% CI 1.07-2.43) and without (HR=2.61; 95% CI 1.17-5.84) an infectious etiology, regardless of the initial cancer stage. This study was the first to date to demonstrate the role of HIV in cancer survival for both AIDS-defining and non-AIDS-defining malignancies in a resource-limited, HIV-endemic region. Our results extend the established relationship between HIV and cancer incidence to also include a role for HIV in cancer patient outcomes, an increasingly important question as the number of patients diagnosed with both HIV and cancer continues to grow.