Clinical outcomes of adult patients with relapsed Ewing sarcoma: A 30-year single institution experience.

Abstract

10041 Background: There is a paucity of information in the literature on adult patients with Ewing sarcoma (ES). This single institution retrospective study specifically aims to determine the prognostic factors that influence the outcome of adult patients who relapse following treatment for localized ES. Methods: The records of 69 patients 18 years and older with localized ES seen at the Mayo Clinic from 1977-2007 who relapsed following initial treatment were studied retrospectively. Early and late relapse were defined as prior to or greater than 2 years from initial diagnosis. Factors relevant to prognosis and survival were analyzed by statistical methods. Results: The median age at initial diagnosis was 28 years (range 18-60). Median follow up was 38 months (range 3.8-293). The 5-year post relapse (PRS) survival for the total group was 22.3%. Gender, site of primary tumor, local control modality, tumor size and age had no influence on outcome. The only statistically significant prognostic markers were site of initial relapse and time to first relapse, using the 2 year cut-off. The probability of 5-year PRS for patients who relapsed locally only was 50.2% versus 13.3% for distant relapse versus 16.67% who relapsed initially at both local and distant sites (p= 0.0209). Similarly, time of relapse ≤2 years versus >2 years from original diagnosis correlated with outcome: 7.6% versus 50.2% 5-year PRS respectively (p= <.0001). These prognostic factors remained significant on multivariate analysis. Conclusions: Adult patients with localized Ewing sarcoma who relapse locally or greater than 2 years following initial diagnosis have a better survival than patients who relapse distantly or prior to the 2-year time point. Aggressive salvage therapy may be warranted in this population.