Human Immunodeficiency Virus–Associated Squamous Cell Cancer of the Anus: Epidemiology and Outcomes in the Highly Active Antiretroviral Therapy Era

Abstract

To evaluate and determine predictors of squamous cell carcinoma of the anus (SCCA) outcomes in the highly active antiretroviral therapy (HAART) era for HIV-positive and -negative individuals using large national Veterans Affairs (VA) Administration databases. We used the VA administrative databases to perform a retrospective cohort study in 1,184 veterans diagnosed with SCCA between 1998 and 2004. We calculated HIV infection rates and used logistic regression to identify epidemiologic factors that were associated with HIV infection. Kaplan-Meier curves and Cox proportional hazards models were calculated to compare survival between HIV-positive and HIV-negative veterans. In our cohort, 175 patients (15%) were HIV positive. The median age of the HIV-negative and -positive patients was 63 and 49 years, respectively (P < .001). Individuals with HIV were eight times more likely to be male (P = .01) and three times more likely to be African American (P < .001). There were no differences between HIV-positive and HIV-negative individuals in the receipt of treatment. The 2-year observed survival rates were 77% and 75% among HIV-positive and HIV-negative individuals, respectively. In multivariate Cox analysis, significant predictors of survival were age, sex, metastasis at diagnosis, and comorbidity score. HIV infection did not affect survival. A noteworthy proportion of individuals with SCCA in the VA system are HIV positive. HIV-associated SCCA seems mainly to be a disease among younger men. Survival of SCCA is equivalent between HIV-positive and HIV-negative individuals in the HAART era. Treatment should not be withheld or deintensified based on HIV status.