Incidence of soft tissue sarcoma in Taiwan: A nationwide population-based study (2007–2013)

Background: Asian studies on soft tissue sarcoma (STS) incidence, irrespective of the primary site, are scant. Methods: STS data were acquired from the population-based 2007–2013 Taiwan Cancer Registry of the Health and Welfare Data Science Center, Taiwan. Histological subtype-, site-, sex-, and age-specific STS incidence rates were analyzed according to the 2013 classification of the World Health Organization. Results: In total, 11,393 patients with an age-standardized incidence rate (ASIR) of 5.62 (95% confidence interval, 5.51–5.73) per 100,000 person-years were identified. Overall, a male predominance (sex-standardized incidence rate ratio, 1.2) was noted, and the rate increased with age, peaking at >75 years. Approximately 30% of STSs occurred in connective, subcutaneous, and other soft tissues and 70% in other sites. In addition to connective, subcutaneous, and other soft tissues, the three most common primary sites were the stomach (15.9%), skin (14.3%), and small intestines (10.5%). Gastrointestinal stromal tumor was the most common subtype (29.2%; ASIR, 1.55/100,000 person-years), followed by liposarcoma (11.5%; ASIR, 0.63/100,000 person-years) and leiomyosarcoma (9.7%; ASIR, 0.53/100,000 person-years). Compared with relevant data from Western countries, the incidence rate of angiosarcomas was higher than that in other regions, whereas the incidence rates of leiomyosarcoma and Kaposi sarcoma were lower than those in other regions. Conclusion: STS incidence varied by histological subtype, sex, age, and primary site in an Asian population. Our results suggested regional and racial discrepancies in the incidence rates of certain STS subtypes.