Racial and Ethnic Disparities in the Incidence and Trends of Soft Tissue Sarcoma Among Adolescents and Young Adults in the United States, 1995-2008

Purpose: The aim of this study was to examine racial/ethnic disparities in the incidence rates and trends of soft tissue sarcoma (STS) by gender, age, and histological type among adolescents and young adults (AYAs) aged 15-29 years. Methods: The 1995-2008 incidence data from 25 population-based cancer registries, covering 64% of the United States population, were obtained from the North American Association of Central Cancer Registries. The Surveillance, Epidemiology and End Results AYA site recode and International Classification of Diseases for Oncology, 3rd Edition, were adopted to categorize STS histological types and anatomic groups. Age-adjusted incidence rates and average annual percent change (AAPC) were calculated. Results: The incidence of all STSs combined was 34% higher in males than females (95% CI: 1.28, 1.39), 60% higher among blacks than whites (95% CI: 1.52, 1.68), and slightly higher among Hispanics than whites. Compared with whites, blacks had significantly higher incidence of fibromatous neoplasms, and Hispanics had significantly higher incidence of liposarcoma. Whites were more likely to be diagnosed with synovial sarcoma than blacks. Black and Hispanic males had significantly higher Kaposi sarcoma incidence than white males. The AAPC of all STSs combined showed a significant decrease from 1995 to 2008 (AAPC = -2.1%; 95% CI: -3.2%, -1.0%). However, after excluding Kaposi sarcoma, there was no significant trend. Conclusion: The incidence rates of STS histological types in AYAs vary among racial/ethnic groups. The declining trends of STS are due mainly to decreasing incidence of Kaposi sarcoma in all races/ethnicities. Research to identify factors associated with racial/ethnic disparities in AYA STS is necessary.