The natural history of epithelioid sarcoma. A retrospective multicentre case-series within the Italian Sarcoma Group.

Introduction: This case-series is aimed to describe the natural history of epithelioid sarcoma (ES) and to provide insights into the differential clinical behaviour of its two variants ("classic-type" and "proximal-type"). The value of a subtype-adapted grading system based on pathological features is explored.
Methods: Data from consecutive, primary, localised, INI1-deleted ES operated at three Italian sarcoma reference centres (1995-2015) were included. Centralised pathological review was performed. Classic-type ES was broken down into "high-grade" and "low-grade", according to number of mitoses, evidence of necrosis and nuclear atypia. Five- and 10-year overall survival (OS) and crude cumulative incidence (CCI) of local recurrence (LR) and distant metastasis (DM) were estimated.
Results: Fifty-two patients were included. 5- and 10-year OS estimates were 70% and 47% in the whole series, 57% and 37% in patients with proximal-type ES, 77% and 54% in patients with classic-type ES (P = 0.02). In classic-type ES, 5- and 10-year OS was higher for low-grade (95% and 72%, respectively) than high-grade tumours (P = 0.002). 5- and 10-year CCI estimates for LR were 21% and 33% in the whole series. 5- and 10-year CCI estimates for DM were 35% and 39% in the whole series, both 28% in classic-type ES, 47% and 59% in proximal-type ES (P = 0.03).
Conclusions: Suffering from a proximal- or a classic-type is the stronger predictor of outcome in patients with localised ES, with proximal-type ES patients having lower survival due to a higher tendency toward metastatic spreading. However, the "high-grade" classic-type ES was associated with outcomes close to proximal-type ES.
Competing Interests: Declaration of competing interest AMF received institutional clinical trials support from Amgen Dompé, AROG Bayer, Blueprint Medicines, Eli Lilly, Daiichi Sankyo Pharma, Epizyme, GlaxoSmithKline, Novartis, Pfizer, PharmaMar and travel grants from PharmaMar. GGB received travel grants and advisory honoraria from Pharmamar and Eli Lilly, advisory honoraria from Eisai. NS received institutional clinical trials support from Amgen Dompé, AROG Bayer, Blueprint Medicines, Eli Lilly, Daiichi Sankyo Pharma, Epizyme, GlaxoSmithKline, Novartis, Pfizer, PharmaMar. PGC has reported advisory roles for Deciphera Pharmaceuticals, Eisai, Eli Lilly, Nektar Therapeutics, speaker's honoraria from Eisai, Eli Lilly, Pfizer, PharmaMar, and conducted studies sponsored by Amgen Dompé, AROG Bayer, Blueprint Medicines, Eli Lilly, Daiichi Sankyo Pharma, Epizyme, GlaxoSmithKline, Novartis, Pfizer, PharmaMar. SSt has received honoraria from Eli Lilly, PharmaMar, Takeda; institutional research grants from Amgen Dompé, Advenchen, Bayer, Eli Lilly, Daiichi Sankyo Pharma, Epizyme Inc., Novartis, Pfizer and PharmaMar; travel grants from PharmaMar and has reported advisory/consultant roles for Bayer, Daiichi, Eli Lilly, Epizyme, Karyopharm, ImmuneDesign, Maxivax and PharmaMar. MS, SLV, FF, DC, DC, SP, AG, APDT, MG, MB, AP, LM have nothing to declare.
(Copyright © 2020 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)