What is the prevalence of VTE in Sarcoma: A meta-analytic review

Purpose: There has been recent increased interest in rates of VTE in sarcoma, with some studies and commentary suggesting that bone sarcoma has higher rates of VTE than soft tissue sarcoma. However, evidence to support the assumption of increased risk is not clearly borne out in the literature. This meta-analysis aims to summarize existing evidence. Methods: A systemic review was performed according to PRISMA protocol using PubMed and EMBASE. Studies describing VTE incidence in sarcoma patients undergoing operative intervention were identified. Meta-analysis of effect sizes was done using the Mantel-Haenszel method with a random effects model. A network meta-analysis of prophylaxis strategies and their effect on VTE rates was also performed. Results: 34 studies were included, including 74635 bone and 5937 soft tissue sarcoma patients respectively and 2283 VTE cases. The analysis found a VTE proportion of 0.045 (0.032- 0.063 95% CI) for sarcoma overall, with no difference between bone and soft tissue sarcoma (p= 0.57). There was significant heterogeneity in the studies (tau2 = 1.24, I2 = 94.5%), however results were not significantly changed when accounting for outliers. Network meta-analysis of prophylaxis strategies included 2556 observations for 8 treatment types and 45 treatment arm pairs. Treatment strategies were compared against proportions of VTE with no prophylaxis. No treatments were identified as superior to no prophylaxis. Heterogeneity within this arm of the study was low (I2 = 34.5%), however risk of bias is elevated mainly due to the designs of the included studies and relatively few comparisons. Conclusion: Published data does not show evidence of increased risk of VTE in patients with bone sarcoma compared with soft tissue sarcoma, based on meta-analysis of 34 studies including 85425 patients. This proportion is substantially lower than some rates previously quoted in the literature, and may be lower than other cancers. A network meta-analysis of prophylaxis for VTE does not identify any strategies which decrease odds of VTE compared to no prophylaxis. However this should be interpreted with caution due to risk of bias. Further work is needed to improve the evidence for or against prophylaxis for VTE in patients with sarcoma.