Epithelioid hemangio-endothelioma (EHE) in NETSARC: The nationwide series of 267 patients over 12 years

Epithelioid hemangioendothelioma (EHE) is an ultrarare sarcoma whose natural history and treatment is not well defined. We report on the presentation and outcome of 267 patients with EHE in the NETSARC+ network since 2010 in France.Patients and methodsNETSARC (netsarc.org) is a network of 26 reference sarcoma centers with specialized multidisciplinary tumor boards (MDTB), funded by the French NCI (INCA). Since 2010, presentation to an MDTB and second pathological review are mandatory for sarcoma patients. Patients' characteristics are collected in a nationwide database regularly monitored with stable incidence since 2013. The characteristics of patients with EHE at diagnosis are presented as well as progression-free survival (PFS), overall survival (OS), and outcome under treatment.Results267 patients with EHE were included in the NETSARC+ database since 2010. Median age in the series was 51 (range 10-90) years, 58% were women. Median tumor size was 37mm (4-220). 48%, 42%, and 10% were visceral, soft parts, or bone primaries. The most frequent sites were liver (28%), lung (13%). 40% were reported to have systemic (i.e. multifocal or metastatic disease) at diagnosis. With a median follow-up of 20 months, OS and PFS rates at 24 months were 82% and 67%, with 10-years projected OS and PFS of 62% and 21% respectively. Male and M+ patients at diagnosis had a significantly worse OS, but not PFS. Local treatment was associated with a favorable survival in localized but not in patients with advanced stage at diagnosis. For 23 patients receiving medical treatment, PFS and OS were 50.2% and 33.2% at 60 months were respectively.ConclusionsEHE is a frequently metastatic sarcoma at diagnosis with a unique natural history. This study shows in a nationwide series over 12 years that most patients progressed but are still alive at 10 years, both in localized and metastatic stages.