[An analysis of incidence trends and characteristics of soft tissue sarcoma in Beijing, 1999-2013]

Objective: To analyze the incidence trends and to describe the characteristics of soft tissue sarcoma (STS) among residents in Beijing from 1999 to 2013. Methods: Medical information of the cases diagnosed as STS(ICD10: C47&C49) from 1999 to 2013 in Beijing was extracted from the population-based database of Beijing Cancer Registry.Crude incidence rate, age-standardized incidence rates to Chinese population (ASRC)and the world population(ASRW) were calculated. The characteristics of the STS cases in different gender and age groups from urban and rural areas were respectively analyzed.The incidence trends and annual percentage changes (APC) during last 15 years were analyzed by using JoinPoint 3.4.3 software. Results: A total of 2 048 cases were diagnosed as STS during the study period and the incidence rate of STS was 1.15 per 100 000 person-years. The ASRC was 0.74 per 100 000 person-years and ASRW was 0.86 per 100 000 person-years, respectively. Except for the impact of changes in the age composition, the APC of ASRW from 1999 to 2013 was 3.95%. For males, the incidence rate was increased from 0.65 per 100 000 in 1999 to 1.51 per 100 000 in 2013, and the APC was 4.27% (P<0.05); For females, the incidence rate was increased from 0.61 per 100 000 in 1999 to 0.91 per 100 000 in 2013, and the APC was 3.38% (P<0.05). In urban area, the incidence rate increased from 1.14 per 100 000 in 2000 to 1.35 per 100 000 in 2013, and the APC was 2.70% (P=0.05); In rural area, the incidence rate increased from 0.57 per 100 000 in 2000 to 0.98 per 100 000 in 2013, and the APC was 4.66% (P=0.04). 85.89%cases were pathologically diagnosed.Among them, undifferentiated pleomorphic sarcoma was the most common subtype, which accounting for 19.22%, followed by liposarcoma (19.04%), malignantnerve sheath tumor (10.18%), fibrosarcoma (10.06%)and sarcoma without definite type(7.22%). Conclusions: The incidence rate of STS is still increasing, especially in the rural area of Beijing. The most common subtypes of STS in different age-groups were different. Further study is needed to explore the high risks of STS in the population with specific characteristics.