Abstract 87P
Background
Rhabdomyosarcoma (RMS) is a rare soft tissue sarcoma, defined as a proliferation of immature cells destined to form striated skeletal muscle. It has poor prognosis in patients with refractory or relapsed disease to the first-line of treatment. The aim of this retrospective study is to evaluate the overall survival (OS) and the progression-free survival (PFS) in patient receiving treatments.
Methods
An evaluation of the clinical characteristic of 21 patients with diagnosis of RMS since 2018 was performed. Response rates were evaluated by RECIST 1.1. Prognostic factors such as age, size of the primary tumor, histological subtype, lymph node involvement, FOXO1 rearrangement and first-line treatment were evaluated. Survival was analyzed using Kaplan-Meier.
Results
21 patients were evaluated; median age was 27 years and 61.9% were men. 33.3% were alveolar and 65.7% were nonalveolar. Half of the patients presented lymph node metastases at diagnosis and only 33.3% debuted with metastatic disease. Only one third of patient had FOXO1 rearrangement. IVADO (ifosfamide, vincristine, actinomycin D and doxorubicin) regimen presented a lower OS 14 month compared to 28 month in patient treated with IVA (without doxorubicin). P=0.049. The response rate at first-line was 66%, but the median time until relapse was 3 month (0-20month) 11 patient were treated at second-line. Different schemes were performed: 54% of the patient were treated with VIT (vincristine, ifosfamide and temozolamide), 27% were treated with BOMP/EPI, others schemes such as gemcitabine plus docetaxel or epirubicin plus ifosfamide were also used. OS was 24 months in VIT schema, 20 months in gemcitabine plus docetaxel and 12 months in BOMP/EPI schema, P=0.016.
Conclusions
Rhabdomyosarcoma is an aggressive soft tissue sarcoma with poor prognosis in adults. Refractory or relapsed disease has few treatment options based on chemotherapy with poor data in terms of OS and PFS. IVA and IVADO are standard of care; however, in our data over 50% of patients relapsed. In second-line, VIT is the most used schema with a higher OS. More investigation to develop new treatment options is required.
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.