Outcomes of extra-skeletal versus skeletal Ewing sarcoma patients treated with standard chemotherapy protocol.

Abstract

11027 Background: Extra-skeletal ewing sarcomas (ES) are rare, and data on outcomes following standard ES chemotherapy protocols are very limited. Methods: We retrospectively collected data on skeletal and extra-skeletal ES patients who presented with localized disease from January, 2006 to June, 2018. Disease and treatment characteristics were compared between the two groups by the chi-square test. Overall survival (OS) and local recurrence free survival (LRFS) were estimated by the Kaplan-Meier method and compared by the Log-rank test. Results: A total of 120 patients were included. Twenty-nine (24%) had extra-skeletal and 91 (76%) had skeletal ES. Location was in the extremity in 51 (43%) and non-extremity in 69 (57%). For extra-skeletal ES, tumors originated from soft tissue in 23 (79%), and viscera in 6 (21%). All patients received standard vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide (VDC-IE), with a plan for local control at week 12 of the protocol. Local control was by surgery in 76 (63%) and radiotherapy in 44 (37%). At a median follow up of 38 months, there was no difference in 5-year OS between extra-skeletal and skeletal ES patients (67% and 70% respectively, p = 0.96). Patients with visceral ES had inferior 5-year OS compared to all others (soft-tissue extra-skeletal and skeletal ES); 33% vs. 72%; p = 0.013. Resectability rate was not different between extra-skeletal and skeletal ES patients (54% and 69% respectively, p= 0.11). Furthermore, among patients who underwent surgery, there was no difference between extra-skeletal and skeletal ES patients in R0 resection rate (86% and 89% respectively, p= 0.52) and poor ( < 90%) tumor necrosis rate (62% and 46% respectively, p= 0.31). However, more local recurrences (28% vs. 10%, p= 0.034) and inferior 5-year LRFS (74% vs. 83%; p = 0.042) were observed in the extra-skeletal group, although more extra-skeletal patients received adjuvant radiotherapy; 11 (73%) vs. 21 (36%), p = 0.01. Conclusions: Patients with localized extra-skeletal ES have OS outcomes that are comparable to skeletal ES treated with standard VDC-IE chemotherapy. However, extra-skeletal ES patients are at significantly higher risk of local recurrence.

Ewing Sarcoma With Emphasis on Extra-skeletal Ewing Sarcoma: A Decade’s Experience From a Single Centre in India

“…Of the total of 346 suspected ESFT, 44 (20), leg (4), popliteal fossa (2), gluteal region (5), cheek (2), orbit (2), nose and nasopharynx (2), scalp (1), neck (7), parapharyngeal (2), chest wall (29), mediastinum and thorax (5), paraspinal (20), abdomen and retroperitoneum (14). Visceral tumours were noted in 34 (22.22%) patients and the sites included ovary (4), cervix (3), vagina (1), kidney (7), bladder (2), prostate (1), lung (4), breast (5), lymph node (3), intestine (2), and brain (2).…”

“…7 , 12 , 18 - 22 Furthermore, involvement of the extremities between skeletal and extra-skeletal tumours was observed to be statistically significant in our study. Salah et al 14 reported soft tissue location in 23 (79%). Visceral ESFTs have been described in studies with small sample size, ranging from 29 to 58 with percentage of such cases varying from 6% to 21% ( Table 3 ).…”

“…12,13,16 The reported frequency of extra-skeletal location of tumours in various series ranged from 21% to 31% in cohort ranging from 120 to 2202 patients. 12,14,15 Reports from India described extra-skeletal tumours in small sample size of 51 to 58 patients and described the frequency to range from 23% to 29%. [19][20][21] In this study of 302 patients, ESFT of extra-skeletal location was seen in 50.7% with diagnosis in visceral organs being more.…”

“…Visceral ESFTs have been described in studies with small sample size, ranging from 29 to 58 with percentage of such cases varying from 6% to 21% (Table 3). 14,[19][20][21] The significant number of ESFTs in visceral location in this study may probably be due to heightened awareness and application of IHC, FISH, and RT-PCR as diagnostic methods. Molecular tests were more frequently (47.06%) performed to establish the diagnosis in visceral ESFT, when compared with skeletal or soft tissue location, highlighting the importance of ancillary techniques for accurate diagnosis.…”

“…Availability of ancillary techniques in diagnostic surgical pathology enables accurate diagnosis of more tumours in the extra-skeletal location. 12 - 14 The clinicopathological features and prognosis were reported to be different in skeletal and extra-skeletal tumours. 12 - 21 This article aims to study the clinicopathological features and the role of ancillary techniques in the diagnosis of ESFT with particular emphasis on extra-skeletal soft tissue and visceral location.…”