Evaluating the Soft Tissue Sarcoma Paradigm for the Local Management of Extraskeletal Ewing Sarcoma

Abstract

Objectives We reviewed our experience treating patients with localized extraskeletal Ewing sarcoma (EES) to determine optimal local management strategies for this rare disease. Methods Sixty patients with localized EES treated at our institution between 1994 and 2018 were reviewed. The Kaplan‐Meier method was used to estimates disease outcomes. Results The median follow‐up time was 74 months (interquartile range [IQR], 17–121). Half the patients (n = 30) received combined‐modality local therapy (CMT) with both surgery and radiation therapy (RT), whereas the other half received single‐modality local therapy (SMT) with either surgery or RT. All patients received chemotherapy. The 5‐year overall survival was 76%. Twenty‐two patients (37%) developed recurrence at a median time of 15 months (IQR, 5–56 months) resulting in 3‐year progression‐free survival (PFS) of 65%. On univariate analysis, the use of both neoadjuvant and adjuvant chemotherapy was associated with improved 5‐year PFS (71% vs. 50%, p = .04) compared with those who received one or the other. Furthermore, 11 patients (18%) developed local recurrences at a median time of 14 months (IQR, 2–19 months), resulting in a 5‐year local control (LC) rate of 77%. Use of CMT was not associated with improved LC (83% vs. 72% SMT, p = .41). Also, use of CMT was the only factor associated with poorer disease‐specific survival (vs. SMT; hazard ratio, 3.4; p = .047; 95% confidence interval, 1.01–11.4). Conclusion For patients with EES, CMT was not associated with a decreased rate of local relapse. These data suggest that SMT alone may be sufficient for LC in select patients. A multi‐institutional collaborative effort should be considered to validate these findings. Implications for Practice Extraskeletal Ewing sarcoma is a rare chemosensitive sarcoma whose clinical course more closely follows Ewing sarcoma of bone rather than that of other soft tissue sarcomas. Based on this study, combined‐modality local therapy did not confer a local control advantage compared with single‐modality local therapy. Therefore, single‐modality local therapy is likely adequate in select patients with favorable disease features, which has the advantage of ensuring prompt administration of systemic therapy. A multi‐institutional collaborative effort is warranted to determine which patients may benefit from de‐escalated local therapy.

A case of an upper anterior abdominal wall extra-skeletal Ewing sarcoma- soft tissue reconstruction with medial intercostal artery perforator flap and free anterolateral thigh fasciocutaneous flap with arteriovenous loop graft

“…Ewing sarcoma has an aggressive behaviour, thus approximately 20–25% of patients present with metastasis at the time of diagnosis, and are usually resistant to intensive therapy [ 2 ]. EES typically has a better prognosis than skeletal Ewing sarcoma [ 3 ]. Our patient did not have any constitutional symptoms besides the growth on the anterior abdomen.…”

“…In view of the nature of the EES to mimic other soft tissue tumour, the diagnosis was only made post-operatively following histopathological examination. Regardless of the primary site of involvement, Ewing sarcoma is known to be comprised of the characteristic small round blue cells [ 3 ].…”

“…Treatment of Ewing's sarcoma is multimodal, comprising of surgery, radiation, and multidrug chemotherapy [ 1 ]. However, EES is a relatively rare entity and there is limited data to guide local therapy [ 3 ]. Some studies demonstrate that combined-modality of local therapy with both surgery and radiation therapy are not guaranteed to lower recurrence rate, thus suggesting that the single-modality local therapy alone may be sufficient for select patients [ 3 ].…”

“…However, EES is a relatively rare entity and there is limited data to guide local therapy [ 3 ]. Some studies demonstrate that combined-modality of local therapy with both surgery and radiation therapy are not guaranteed to lower recurrence rate, thus suggesting that the single-modality local therapy alone may be sufficient for select patients [ 3 ]. Radiotherapy is indicated in cases where there is residual disease after surgical intervention, or where surgery is contraindicated [ 3 ].…”

Hypofractionated Radiation Therapy for Unresectable or Metastatic Sarcoma Lesions

“…Sixteen (23%) patients were treated due to oligoprogression for which both the 1-and 2year OS was 73%, respectively. Six (38%) patients developed local relapse at a median of 12 months (IQR, [6][7][8][9][10][11][12][13][14][15][16][17][18], and all but one (94%) developed distant progression at a median time of 4.5 months (IQR, 1-7). The median systemic therapy break was 12 months and RT provided a median addition of 6 months off systemic therapy (IQR 2-11.5).…”