(P 090) TEN-YEAR INCIDENCE AND MORTALITY OF SOFT TISSUE SARCOMAS IN THE NATIONAL CANCER CENTRE SINGAPORE, FROM 2012 TO 2021

Objective: Soft tissue sarcomas (STS) are heterogeneous tumours comprising 1% of adult solid malignancies but account for >20% of tumours in the paediatric and young adult population. Median overall survival in advanced STS is dismal at only one year. The National Cancer Centre Singapore (NCCS) is the largest cancer centre in multiracial Singapore which sees nearly 70% of Singapore’s cancer patients. We report the incidence and mortality of STS in Singapore over the last decade, from 2012 to 2021.

Methods: Patient records were retrieved using Singapore’s Electronic Health Intelligence System (eHINTS) database. Non-benign STS entities as defined by the 5th Edition of the World Health Organization (WHO) Classification of Tumours were included in this analysis. Where specific diagnoses were unclear, patient records were also individually examined. Graphs, tables and error analyses were performed on MedCalc® Statistical Software version 20.111 (MedCalc Software Ltd, Ostend, Belgium; https://www.medcalc.org; 2022), Microsoft Excel 2019 and Python 3.1.4.

Results: From 2012-2021, a total number of 91,036 cancer cases were seen at the National Cancer Centre Singapore. Of these, non-benign STS accounted for 1,676 cases, across 50 subtypes of STS (Table 1). Males accounted for 45.8% and females 54.2% of STS (Figure 1A). In terms of racial distribution, Chinese accounted for the majority with 72.7 %, Malays 9.5 %, Indians 5.4 % and 12.4% were of other races (Figure 1B). The distribution of STS by age group differed from that of all cancers, with a higher proportion of patients in younger age groups in STS compared to all cancers (Figure 1C). STS also accounted for a higher proportion of total cancer cases in younger age groups, especially those younger than 20 years of age (Figure 1D). The average annual incidence of non-benign STS in our centre, as a proportion of total cancer cases, was 1.83 ± 0.9 % (Figure 2A). This is higher than in other countries. The annual incidence of STS as a proportion of total cancer cases in the United States of America is 0.7% as per the Surveillance, Epidemiology and End Results (SEER) program, 0.5% in France as per Sarcomes on the NetSarc clinical reference network and 0.9% in the United Kingdom as reported by the Cancer Research UK (Figure 2B). The age distribution of STS patients in our centre skews towards the younger age groups, as compared to the distribution reported on the SEER program, especially from ages 35-54 (Figure 2C). The mortality of STS across different races showed Chinese patients having a higher average survival time than Malay and trended towards better survival compared to Indian and Others (Figure 3). Further analyses of incidence and mortality across other domains were also performed and will be presented.

Conclusion: There is a higher proportion of STS patients within younger age groups compared to that of all cancers in the National Cancer Centre Singapore. We show that the incidence of STS as a proportion of total cancer cases in the National Cancer Centre Singapore is two to three fold higher than that reported in databases from other countries such as the United States of America, France and the United Kingdom. Since STS is proportionally more common in the younger age groups, a possible explanation could be that Singapore has a higher proportion of younger people than these countries. The skewing of STS patients towards the younger age groups compared to data from the SEER program also highlights the need to focus on the unique needs of young adults undergoing STS treatment in our centre, as well as in other countries with younger populations. The reasons for the racial differences in outcomes seen, with the Chinese demonstrating better survival are unclear. Whether this is due to a difference in biology, culture, or socio-economics, remains to be determined.

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Table 1.pdf