Abstract 1643P
Background
ES is a highly curable malignancy. There is sparse data available regarding outcome and prognostic markers, especially from LMICs, and merits further exploration.
Methods
Retrospective analysis of histologically confirmed, non-metastatic ES, registered between 2013 to 2018 in Tata Memorial Centre, Mumbai, India, uniformly treated with EFT-2001 protocol was carried out. Demographics, survival and prognostic markers were evaluated.
Results
There were 1169 patients with ES, of which 575 were non-metastatic. 467 were offered treatment with the EFT 2001 regimen. Of these 467 patients, 398 (85.2%) were treatment naïve, 247 (52.8%) completed the planned treatment and constituted the per-protocol population. Median age was 15 years; 47% were males. 68% had skeletal (48% extremity, 20 % axial) involvement and the commonest primary site was the femur (14%). Definitive therapy was surgery in 303 (65%) and radiation in 122 (26%) and the rest (9%) defaulted before local therapy. For treatment naïve patients, the intention-to-treat (ITT) population, at a median follow-up of 37 (range 0-87) months, had a 5-year disease-free survival (DFS) and overall survival (OS) of 61% (95% CI 55% - 67%) and 80.5% (95% CI 75.3 - 86.2%), respectively. For the per-protocol cohort, at a median follow-up of 41 (6- 87) months, the 5-year DFS and OS were 67.8% (95% CI 61.8% - 74.5%) and 88% (95% CI 83.1 - 93%), respectively. For the non-treatment naïve cohort at a median follow-up of 34 (1 – 76) months, the 5-year DFS and OS were 59.1% (95% CI 43.8 - 79.9%) and 75.4% (95%CI 58.5- 97.2%), respectively. Significant grade 3/4 toxicities were anaemia (58%), febrile neutropenia (57%), thrombocytopenia (38%), peripheral neuropathy (16%), nausea-vomiting(1%), diarrhoea (4%), cardiac (3%), renal (1%), hepatic (8%), encephalopathy (1%) and 1% chemo-toxic deaths. In both ITT and per-protocol analysis, with primary extremity site, baseline haemoglobin and surgical treatment post chemotherapy, tumour -necrosis ≥ 95% were found as independent prognostic markers in multivariate analysis for DFS and OS, and also tumour size for DFS.
Conclusions
Patients with non-metastatic, treatment-naïve ES treated with uniform EFT-2001 and completed per-protocol treatment have a significantly better prognosis and internationally comparable results. Inadvertent prior treatment and non- compliance must be addressed adequately in LMICs to improve outcomes.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Tata Memorial Hospital, Mumbai.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.