436P - Oncologic outcomes in patients with extraskeletal Ewing’s sarcoma (EES): A tertiary care centre experience

Background

Extraskeletal Ewing’s sarcoma (EES) is a rare entity, accounting for 15% of all Ewing’s sarcomas. Multimodality management with aggressive surgical resection, adjuvant chemotherapy, and radiotherapy are cornerstones for good oncological outcomes. We analyzed homogenously treated patients at our Centre and evaluated the oncological outcomes.

Methods

Between March 2005 and March 2020, we found 74 evaluable cases of ESS with a median age of 25 years (range 5 - 52), 43 were males and 32 were female patients. All patients underwent staging work-up with PET SCAN. All received (neo) adjuvant chemotherapy, surgical resection, and radiation therapy as per standard guidelines. Sixty-two patients were non-metastatic and 12 were metastatic at presentation. Recurrent cases were 15 while 59 had the primary disease. The thigh was the most common site (30) followed by the leg (12). Only 21 (29%) patients had tumor size < 5cm at presentation. Six patients had a margin-positive resection and 68 had free margins. Kaplan Meier method was used for evaluating overall survival (OS).

Results

At a median follow-up of 105 months, 42 patients were alive, 28 had died and 4 were lost to follow-up. Twenty-five patients had recurrence (LR-2, LR+DR - 7, DR -16). One patient died while on adjuvant chemotherapy. Five-year overall survival was 62.2%. On univariate analysis, tumor size < 5cm, and non-metastatic disease at presentation were significantly associated with better overall survival. None of the other factors like age, gender, location of the tumor, depth, or response to chemotherapy were found to be significant prognostic factors in Extraskeletal Ewing’s sarcoma.

Conclusions

The presence or absence of metastasis in patients with Extraskeletal Ewing’s sarcoma had a significant effect on overall survival. Tumor size when less than 5cm had better overall survival. Age, site, and response to chemotherapy did not impact survival in our study, possibly due to small number of cases.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.