Epithelioid sarcoma: prognostic factors and survival in a series of patients treated at a single institution.

Background: Epithelioid sarcoma (ES) is a rare subtype of soft-tissue sarcoma of unknown histogenesis. Typically, it occurs superficially as single/multiple nodules (nodular ES), or in deeper tissues as a mass. The correlation between initial presentation and clinical outcome was investigated.

Methods: Fifty-four consecutive patients surgically treated at a single referral center were retrospectively reviewed. Thirty-six patients presented with a primary and 18 with a recurrent tumor. Potential prognostic clinicopathological variables, including macroscopic features at first presentation, were tested by univariable and multivariable analysis with respect to overall (OS), metastasis-free (MFS), and local recurrence-free survival (LRFS).

Results: The 10-year OS was 61.8% for the whole series. Thirty patients relapsed; in detail, local and distant failure occurred in 14 (25.9%) and 24 (44.4%) patients, respectively. The lymph node involvement rate was 16/54 (29.6%). In both the whole series and the subset of patient with primary ES, single localized tumor correlated with increased OS at multivariable analysis; occurrence of nodal involvement during postoperative follow-up correlated to worse OS and MFS. Nodular ES was an independent predictor of worse LRFS. In univariable analysis, nodular ES was associated with smaller tumor size, distal limb locations, earlier classification of malignant tumor (TNM) stage, and higher amputation rate. A statistical difference in the pattern of failure between nodular and mass ES was found.

Conclusions: Primary tumor macroscopic features seem to correlate to different local aggressiveness and failure patterns. Better prognosis is associated with single localized disease stage and no occurrence of locoregional spread.