Incidence, distribution of histological subtypes and primary sites of soft tissue sarcoma in China

OBJECTIVE: Soft tissue sarcomas (STSs) are rare malignancies deriving from mesenchyme. In this study, we reported the epidemiology of STS in China using population-based cancer registry data. METHODS: In 2017, qualified data from 339 cancer registries were included in the national database. All STS cases were retrieved based on the morphological and topographical codes of International Classification of Diseases for Oncology, and were categorized into different histological subtypes and primary sites accordingly. Nationwide new STS cases were estimated using incidence rate of STS and the national population, and were reported for gastrointestinal stromal tumor (GIST) and STSs other than GIST separately by sex and region. Distribution of histological subtypes and primary sites of STS were calculated, as well as primary sites of GIST. RESULTS: Approximately 39,900 new STS cases occurred nationwide in China in 2014, accounting for 1.05% of overall cancer incidence. The crude incidence rate was 2.91/100,000 and generally increased with age. An overall female predilection was found. GIST was the most common histological subtype, followed by nerve sheath tumor and malignant peripheral nerve sheath tumor, leiomyosarcoma, liposarcoma, and fibrosarcoma. About 67.5% of GIST occurred in stomach while 1.4% were recorded outside the gastrointestinal tract. Connective, subcutaneous and other soft tissues were the most common primary site, of which extremities were the major subsite. CONCLUSIONS: The burden of STS is not serious in China relatively. However, due to their histological and topographical complexity, STSs should not be unnoticed, and more basic and clinical studies should focus on STSs.