Prognostic Value of Relevant Clinicopathologic Variables in Epithelioid Sarcoma: A Multi-Institutional Retrospective Study of 44 Patients

Abstract

Background: Epithelioid sarcoma (ES) is an extremely rare soft tissue sarcoma. Recently, the proximal variant has been reported to be a more aggressive subtype; however, as most reports of ES have involved small case series, the actual prognostic implications remain unclear. We investigated the clinicopathological features of patients with ES to identify the prognostic factors that influence survival.

Methods: We retrospectively analyzed the clinicopathological features of 44 patients with ES who had been treated at our institutions between 1991 and 2011. Among these patients, 26 were diagnosed histologically as having classic-type ES, whereas the remaining 18 had proximal-type ES. Thirty-three of the patients, all without distant metastases, underwent curative surgery, and the remaining 11 with distant metastases (M1) received palliative treatment.

Results: The proximal subtype was significantly correlated with a proximal tumor location, distant metastases at presentation, presence of rhabdoid cells, a higher tumor grade, and vascular invasion. The overall survival (OS) rate at 5 years for the 44 patients was 45 %. A superficial tumor location and lymph node metastases (N1) at presentation were independently predictive of local recurrence-free survival (LRFS), and N1 and M1 tumors were independently predictive of distant metastasis-free survival and OS, respectively. The proximal subtype was associated with unfavorable LRFS and OS, although not to a statistically significant degree.

Conclusions: Proximal-type ES has significantly more aggressive clinicopathological features than classic-type ES, and lymph node or distant metastasis has the most critical impact on prognosis.

Fig. 1

a Local recurrence-free survival rates for the 33 patients with M0 tumors were 82 and 62 % at 2 and 5 years, respectively. b Distant metastases-free survival rates at 2 and 5 years were 56 and 35 %, respectively. c Overall survival rates for the 44 patients overall were 70 and 45 % at 2 and 5 years, respectively. d Overall survival rates for the 33 patients with M0 tumors were 81 and 57 % at 2 and 5 years, respectively, and those for the 11 patients with M1 tumors were 33 and 0 %, respectively (p < 0.001). e Overall survival rates for the 26 patients with classic-type epithelioid sarcoma were 81 and 53 % at 2 and 5 years, respectively, and those for the 18 patients with proximal-type epithelioid sarcoma were 53 and 33 %, respectively (p = 0.124)