Clinicopathological and oncological outcomes in upper extremity Ewing's sarcoma: A single institutional experience.

BACKGROUND: Ewing's sarcoma is highly aggressive bone tumor having predilection for younger age groups with t (11,22) translocation, recombines the FLI-1 and EWS genes on chromosome 22. This disease requires multi-disciplinary treatment withneo-adjuvant chemotherapy followed by surgery or radiotherapy and adjuvant chemotherapy. This study was aimed to assess the demographic distribution, clinical behaviour and oncological outcome of Ewings Sarcoma involving upper extremity.

METHODS: From 2015 to 2022, 45 patients of upper extremity Ewing's sarcoma underwent treatment at a territory cancer centre. A total of 26 patients treated with surgical management were included in the study comprising 15 males (57.7 %) and 11 females (42.3 %). Mean age of presentation was 26 years (3-43 years). The most common site for Ewings sarcoma of upper extremity was Humerus(42 %) followed by Scapula(27 %), Radius(15 %), Ulna(8 %), Metacarpals(4 %) and Clavicle(4 %). Out of 26 cases, 19 (73%) underwent limb salvage surgery and 7 (27%) underwent ampuation surgery.

RESULTS: In limb salvage group reconstruction with Extra-corporeal radiotherapy (ECRT), Ulna centralization, Megaprosthesis and 3D printed scapula was performed following wide resection of tumor. In Amputation group ray resection in one case and forequarter amputation was performed in six cases. Mean serum LDH value was 335 IU/L (2.3X Normal value) and serum albumin was 4.04 gm/dl. Mean tumour necrosis after neo-adjuvant chemotherapy was 68 %. Out of 26 cases, 19(73 %) cases underwent limb salvage and 7 patients underwent amputation surgery. Out of 26, 13 (50 %) patients developed metastasis on follow up. The Event free survival (EFS) in current study was 70 % at 12 months and 40 % at 24 months. Mean Event free survival (EFS) in current study was 33.5 months (22.3-44.6) and Median Event free survival (EFS) in current study was 25 months (19.7-30.2).

CONCLUSION: This study characterises demographic and oncologic outcomes of upper extremity ewings sarcoma in Indian subpopulation. Pain and swelling were prominent clinical findings at presentation in patients with upper extremity Ewing's sarcoma. The survival rate following limb salvage surgery in Ewings sarcoma of upper extremity was comparable to that of patients with amputation surgery. Ewings sarcoma of upper extremity was associated with higher LDH level which was raised more than twice the normal range and can led to worse oncologic outcomes. A comparative study on upper extremity and lower extremity ewings sarcoma will be of help to improve literature on this rare disease.