Risk stratification tools to help decide on adjuvant chemotherapy usage in resected soft tissue sarcomas: A 10 year review of an Irish sarcoma centre experience.

Abstract

11575 Background: Soft tissue sarcoma (STS) is comprised of 80 pathologic subtypes based on a combination of distinctive morphological, immunohistochemical and molecular features. Adult-type soft tissue and visceral sarcomas are rare, with an estimated incidence of 4-5/100,000/year in Europe. The National Comprehensive Cancer Network (NCCN) guidelines recommend consideration of neo-adjuvant or adjuvant systemic treatment in resectable stage III (high grade tumours which are >5cm) and also in those who need to undergo an amputation or radical resection with adverse functional outcomes. The Sarculator risk prediction tool has identified a threshold of risk above which the administration of chemotherapy may provide an overall survival benefit. This can be applied to the most common histologic subtypes. Patients affected by these subtypes and with a 10-year predicted OS likelihood <60% are considered as high risk and therefore, should be considered for adjuvant chemotherapy. Alternatively, tumours considered at high risk of recurrence based on size >5cm and high grade histology, may benefit from adjuvant chemotherapy. Therefore, the aim of this project is to review the outcomes of resected extremity/trunk soft tissue sarcoma and assess the prognostic accuracy of these risk prediction methods. Methods: All new patients with resected STS discussed in the STS MDT in Cork University Hospital between Jan 2012 – Dec 2021 were identified. The histology and imaging of the identified patients were reviewed. Data regarding demographics, histology, treatment and outcomes was collected. Risk assessment using AJCC and Sarculator score was done on all patients with an extremity or trunk sarcoma. Overall survival was recorded and assessed including Kaplan Meier method for time to event analysis. Results: 200 patients were identified as having an STS resected - 134 of these were located on the trunk or extremities representing 24 different histological subtypes. Sarculator score was calculated for 60 of these (well differentiated liposarcomas, desmoid tumours, and dermatofibrosarcoma protuberans were excluded). 3 patients received adjuvant chemotherapy and 4 patient neoadjuvant chemotherapy. Overall survival data is presented below. Conclusions: Our cohort is representative of the broad histological subtypes expected in sarcoma. Sarculator score results correlate with international outcomes, with higher scores associated with increased mortality. In our cohort, sarculator score was more predictive of outcome than tumour grade/size alone. [Table: see text]