Background: Kaposi sarcoma (KS) is the most common neoplasm of people living with HIV today. Although the overall incidence of KS has been reported to be declining in the US, KS has strong racial/ethnic, age, and regional diversity in incidence trends.
Methods: We analyzed KS incidence data from the US Cancer Statistics (USCS) registry for the years 2000-2014. The USCS registry is the official data source for federal government-reported cancer incidence statistics and covers 97% of the US population. Women were excluded because of the low numbers of KS cases in certain geographic regions, and our analyses only included 20 to 54 year-old age-group as prior validation studies indicated that ~94% of KS cases in this age-range are HIV-related. We calculated adjusted incidence rates and assessed annual trends among sociodemographic and geographic subgroups using joinpoint regression analysis.
Results: During the study period, 12,549 men were diagnosed with KS. The overall incidence of KS among men decreased from 1.42/100,000 in 2000 to 0.95/100,000 in 2014, decreasing by 3.60% (95% confidence interval [CI], -4.00% to -3.13%) annually. The overall annual percent change (APC) for men significant decreased (-6.27%, p< 0.05) from 2007-2010 and again (-2.13%, p< 0.05) from 2010-2014. Among African American, non-Hispanic Caucasian, and Hispanic men, the incidences in 2014 were 2.37/100,000, 0.49/100,000, and 1.22/100,000, respectively. Although there was a decrease in the APC among African American men from 2000-2014 (-3.31%, p< 0.05), there were differences in the rate of change among African American men by region. In the Northeast, the APC was noted to have 3 joinpoints, with non-significant decreases in incidence in years 2009-2012 (APC=-0.23%, p< 0.05), followed by a significant decrease in years 2012-2014 (APC=-26.17%, p< 0.05). In the Midwest and West there were significant decreases throughout years 2000-2014 (APC=-3.4%, p< 0.05, and APC=-5.59%, p< 0.05, respectively). However, in the South, there has been no significant change in incidence (APC=-0.86%, p>0.05) of KS among African American men.
Conclusions: Geographic disparities in KS incidence remain for African American men in the U.S. Between the years 2000-2014, unlike other regions, the incidence of KS has remained unchanged in the southern U.S.