Abstract 72P
Background
Leiomyosarcoma (LMS) comprises up to 10-20% of soft tissue sarcomas. LMS arises from the smooth muscle cells or from the precursor mesenchymal stem cells that would eventually differentiate into smooth muscle cells present in the muscular wall of the veins. Venous thromboembolism (VTE) is a leading cause of death in patients with cancer. Nevertheless, its prevalence, characteristics, the role of the predictive scores and the association with survival in LMS has not yet been evaluated.
Methods
This retrospective study included 101 patients with LMS treated at a single national reference center for Sarcoma in Barcelona between January 2012 and December 2020. The main objective was to describe the frequency of VTE and its clinical characteristics as well as the accuracy of Khorana and ONKOTEV scores to predict VTE in LMS. Additionally, we evaluated the development of VTE and its association with overall survival (OS).
Results
Median age of the evaluated population was 60.3 years and 60.4% of the patients were women. LMS was grade 3 in 56.5% of the patients. The majority of LMS were located in the lower extremities (31.7%) followed by uterus (24.8%) and retroperitoneum (18%). Tumor size was > 5cm in 76% of the patients and 40.6% had metastases at diagnosis (lungs 63% and liver 19%). VTE diagnosis was more frequent in the metastatic setting than in localized disease (31% vs 18% p = 0.021). Inferior extremities deep vein thrombosis represented 51.6% of VTE events, and in 60.2% of cases LMS was originated also in the lower extremities. Pulmonary embolism represented 25.8% of VTE events, and the most frequent primary LMS locations were retroperitoneum and uterus (53.2% and 30%, respectively). ONKOTEV score achieved better predictive capacity for VTE compared to Khorana (AUC 0.69 vs 0.59) in ROC curves. OS was decreased by the presence of VTE in metastatic patients (39 vs 30 months, HR 0.74, p = 0.053).
Conclusions
VTE is a frequent phenomenon in LMS, particularly in the metastatic disease, with similar incidence to those reported in pancreatic adenocarcinoma. ONKOTEV score showed greater predictive capacity than Khorana score for VTE risk in LMS patients. Our findings suggest a detrimental impact of VTE in OS.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.