617P - The risk of acute myeloid leukaemia in patients with Ewing's sarcoma and trend analysis: A SEER-based study 2000-2020

Background

Ewing sarcoma is a neoplasm of neuroectodermal origin arising from bone or soft tissue. The annual incidence of Ewing sarcoma in children is 2.93 per 1,000,000. Acute myeloid leukaemia (AML) is one of the most common malignancies as a complication of primary cancer therapy. There are very few studies reported the association of Ewing sarcoma with AML. So, our aim is to quantify the risk of developing AML in Ewing sarcoma patients and provide updated evidence to the literature.

Methods

We extracted the data from the surveillance, Epidemiology and End Results (SEER) statistical analysis software package (SEER*Stat, version 8.4.1.2). We used the MP-SIR session to identify patients who had ewing sarcoma as a first primary tumor, then diagnosed with acute myeloid leukaemia as a second primary malignancy between 2000 and 2020. We assessed the SIR as Observed/Expected(O/E) and Excess Absolute Risk (EAR) per 10,000 with a 95% Confidence Interval (CI) and statistical significance at P<0.05.

Results

A total of 2631 patients had a median follow-up of 120+ months. Patient with Ewing sarcoma had an increased risk to develop AML with O/E of 145.98 (95% CI:101.68 -203.03, P<0.05, EAR= 21.79). The total cohort of patients had a PC of 32.7, APC of 1.3 (95% CI: 0.6 -2.0; P<0.05. Female patients had a PC of 46.5, APC of 1.7 (95% CI: 0.5 -2.9; P<0.05). about 35 patients developed acute non lymphocytic leukaemia (ANLL) with O/E 130.92 (95% [CI] 91.19 -182.08; P<0.05, EAR 21.77).

Conclusions

Ewing sarcoma is a very rare tumor that it is hard to assess the risk of multiple primary malignancies associated with it. In this study we found patients who developed a primary Ewing sarcoma had significantly high risk of developing Acute myeloid leukemia especially in the first year after diagnosis, so we recommend to start screening for AML once Ewing sarcoma is diagnosed for early detection and better management plan.

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.