Abstract 1204: Incidences of malignant primary soft-tissue sarcomas regardless of primary site: A nationwide population-based study in Taiwan

Population-based studies on soft tissue sarcomas (STS) incidence beyond extremities and trunk wall are lacking in Asia. In this study, we aimed to report the incidences of STS arise in any part of the body. The data of primary STS registered in the population-based Taiwan Cancer Registry during 2007 and 2013 was acquired via the Health and Welfare Data Science Center, Taiwan. Histologic subtype-, age-, and gender-specific STS incidence rates of all sites were analyzed. A total of 11393 subjects were identified, with an age-standardized incidence rate of 5.62 (95% CI, 5.51-5.73) per 100,000 person-years. Approximately 30% of STS occurred in soft tissues (ICD-O-3 topography codes of C47, C49), and 70% occurred in all other primary sites (ICD-O-3 topography codes of C00-C80 except C47, C49, C40 and C41). The three most common primary sites other than soft tissues were stomach (15.9%), skin (14.3%) and small intestine (10.5%). Gastrointestinal stromal tumor (GIST) was the most common subtype, accounting for 29.2% of STS, followed by liposarcoma (11.5%) and leiomyosarcoma (9.7%). For overall STS, no significant incidence trend was identified during 2007-2013. However, a significant declining trend in incidence rate of undifferentiated pleomorphic sarcoma was found (annual percentage change, APC, -7.8%). By contrast, a significant upward trend was identified in other specified sarcomas (APC, 7.3%). For the first time, this analysis demonstrated that STS incidence varied by histologic subtype, gender, age, and primary site in Asians. In the future, more population-based studies should be performed in Asians for comparison with the results from Western countries to better clarification if racial variation exists in any subtype-specific incidence rates of STS. Citation Format: Giun-Yi Hung, Jiun-Lin Horng, Chueh-Chuan Yen. Incidences of malignant primary soft-tissue sarcomas regardless of primary site: A nationwide population-based study in Taiwan [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1204.