Utility of the ACTG staging criteria to predict survival in AIDS associated Kaposi’s Sarcoma in Uganda

Abstract

Introduction: Kaposi sarcoma (KS) is commonly staged using criteria established by the AIDS Clinical Trials Group (ACTG). ACTG staging is comprised of three dichotomous variables: Tumor extent (T), immune status (I) and systemic symptoms(S). Although validated in the US and Europe, no evaluation has been done in resource-limited settings during the HAART era. Objective We sought to determine whether the ACTG staging criteria is predictive of survival among Ugandan patients with HIV-associated KS and assess the relationship between the Tumor(T),Immune status(I),Systemic symptoms(S) as designated by ACTG staging criteria and their impact on survival among patients with AIDS associated Kaposi’s sarcoma. Methods: A retrospective Kaposi’s sarcoma (KS) chart review carried out between April and August 2009 at the Uganda cancer institute (UCI) Mulago Hospital. Data were abstracted from medical records of adult patients with HIV-associated KS seen at the Uganda Cancer Institute from 2001-2006. A total of 404 out of 2654 charts of eligible participants were retrieved. Using a standard pretested KS abstraction form we documented KS clinical features at first visit and at subsequent follow-up visits including the baseline ACTG stage, HIV co-morbidities, CD4, HAART history, chemotherapy, radiotherapy visits, and final vital status recorded as “Alive” ,“Dead” or “Lost”. We evaluated the association between ACTG criteria and two-year overall survival using Cox proportional hazards and the Kaplan Meier model to explore the relationship between the TIS variables and survival outcomes. Results: The cohort included 404 KS patients: 53.3 % were male, the median age was 35 years (range 18-74yrs), the median CD4 count at diagnosis was 98.5cells/ul (IQR 0, 1411cells/ul). The median survival was 468 days (IQR 141, 1372 days). Conclusion: The Tumor extent and systemic symptoms are more predictive of survival. The immune status does not significantly predict survival. Trunk edema appears to be a predictor of survival in bulky and advanced KS. Combining the tumor extent and systemic symptoms distinctly identifies two main survival groups (T₀S₀ T₀S₁ T₁S₀) with improved survival versus T₁S₁ with poor survival.