Title : A national retrospective cohort study reporting the epidemiology of vascular soft tissue sarcomas in England 2013–2020
Abstract:
Vascular soft tissue sarcomas (VSTS), while rare, are a diverse group of sarcomas which carry a poor prognosis with limited management options. The most common subtype is angiosarcoma but also includes lymphangiosarcomas, malignant haemangioendotheliomas and malignant glomus tumours. Kaposi’s Sarcoma was not included in this dataset. Epidemiological data on incidence and survival rates are scarce.
National data on VSTS and cutaneous subtypes were extracted from the ‘Get Data Out’ National Disease Registration service programme for England, 2013-20. Confidence intervals were measured by using the exact poisson method. Crude incidence rates (CIR) are reported per 100,000 person-years (PY). Incidence rate ratios (IRR) assess the impact of the pandemic on incidence rates between 2020 and 2019 and are reported with poisson confidence intervals and a chi-squared statistic.
From 2013-2020, 1587 new cases of VSTS were diagnosed, with a mean of 198 cases per year and a CIR of 0.33 PY (95% CI 0.29-0.39) in 2013 which increased to 0.37 PY (95% CI 0.32-0.43) in 2020. Of these, 174 were reported as cutaneous origin (not including subcutaneous), with a mean of 22 per year and a CIR 0.04 PY (95% CI 0.03-0.07) in 2013 which increased to 0.06 PY (95% CI 0.04-0.08) in 2020. The incidence rate ratio for VSTS for 2020 vs 2019 was -2.4% (95% CI 0.80-1.19) with a P-value of 0.80. The IRR for cutaneous vascular sarcoma not significant due to small counts. The 5-year net survival reported for 2014-2016 for VSTS was 35.7% (95% CI 31.3-40.1) and was not reported for cutaneous vascular sarcomas due to small counts.
Limitations of this data include lack of more detailed data on subtype and site of VSTS, patient demographics and stage. The 2.4% reduction in incidence rates between 2020 and 2019 is non-significant and a smaller reduction than that seen by many other cancers during the pandemic on the background of healthcare service disruption, which may reflect the aggressive nature of VSTS. The 5-year net survival rate is similar to stage IV melanoma and worse than most other skin cancers. Analysis of these data is key in highlighting this rare group of cancers, to better understand the effectiveness of current treatments and in identifying the direction of further research.
