Modulation of YAP/ TAZ by statins to improve survival in epithelioid hemangioendothelioma (EHE).

Abstract

e23527 Background: EHE is a rare soft tissue tumor of endothelial origin. It is distinguished by the pathognomonic WWTR1-CAMTA1 fusion (WWTR1 is the gene symbol for TAZ) seen in 90% of the tumors. YAP1-TFE3 fusion is less common and seen in 10% of the tumors. YAP and TAZ are critical downstream effectors of the Hippo pathway that regulate tumor development, progression, invasion and metastasis by modulating the expression of many Hippo pathway targets. Recent studies have shown that inhibition of HMG-CoA reductase, a key enzyme of the mevalonate pathway, can regulate YAP/ TAZ by preventing their nuclear accumulation and inhibiting their transcriptional activity. This has led to interest in the role of statins, which inhibit HMG-CoA reductase, as a modulator of YAP/ TAZ that could benefit patients with sarcoma, particularly EHE. Methods: A retrospective analysis was performed on patients with a diagnosis of EHE at M D Anderson Cancer Center. Patients were identified using the electronic database system and screened for statin use using EMRs. Demographic and clinical characteristics were tabulated. KM method was used to assess overall survival and log rank test was used to test survival differences between the statin use and non- statin use groups. All statistical analysis was performed using STATA 14. Results: 226 patients with EHE were identified. 27 of them had recorded statin use during the course of their disease. The median OS for the statin use group was not reached and the mean OS was 221 months. The median OS for the non- statin use group was 123.9 months, while the mean OS was 160 months. The difference in OS was not statistically significant between the two groups. The median follow-up time for our cohort was 36.6 months. Conclusions: Our findings indicate a trend towards improved survival for patients with EHE who have received statins over the course of their disease. Our study is limited by a small number of patients who received statins. Prospective studies are required to assess the therapeutic benefit of statins in EHE. [Table: see text]