Racial disparities in incidence & survival of Kaposi's sarcoma in the United States

BACKGROUND & OBJECTIVES: In the United States (US), Kaposi's sarcoma (KS) is usually seen in the patients affected by human immunodeficiency virus (HIV). The racial differences in the incidence rates and survival of patients with KS have been reported in the US. We undertook this study to analyse the disparities in the race-specific incidence rate and survival of KS patients of two different races in the US based on SEER (Surveillance, Epidemiology and End Results) database. METHODS: Data on KS patients of African-American (AA) and non-Hispanic White (NHW) races who were diagnosed during 1973-2013 were extracted from SEER database to estimate the incidence rates and survival of KS patients. RESULTS: A total of 18,388 NHWs and 3,455 AAs were diagnosed with KS. The age-adjusted incidence rate (AAIR) of KS in patients aged 20-44 yr was 3.8 times higher in AAs than in NHWs. The decline in AAIR of KS among NHWs started during 1989-1994 and preceded decline in the AAIR of AAs. After introduction of highly active antiretroviral therapy (HAART), the incidence continued to decline, but the decrease in the AAIR in AAs [annual percentage change (APC): −6.2; 95% confidence interval (CI): −8.8 to −3.5] was slower than that in NHWs (APC: −10.9; 95% CI: −12.6 to −9.1). The hazard ratio for all-cause mortality in KS patients of the AA race increased from 1.1 (95% CI: 1-1.2) in 1981-1995 to 1.55 (95% CI: 1.4-1.7) in 1996-2013 as compared to those of the NHW race. INTERPRETATION & CONCLUSIONS: Several significant racial disparities that emerged after HAART introduction in the incidence and survival of KS patients continued to persist, despite improvement in care of patients with HIV. Further studies need to be done to find out the underlying factors leading to these disparities.