ESTRO 2024 - Abstract Book

S5440

Radiobiology - Tumour biology

ESTRO 2024

3238

Digital Poster

Replicative stress score as a biomarker of radiotherapy response in soft tissue sarcoma of the limb

Waisse WAISSI 1,2 , Benoit Allignet 1 , Mehdi Brahmi 3 , Armelle Dufresne 3 , Jean-Yves Blay 3 , Gualter Vaz 4 , Francois Gouin 4 , Alexandra Murgey 5 , Marie Karanian 5,2 , Franck Tirode 2 , Marie-Pierre Sunyach 1 1 Centre Léon Berard, Radiotherapy, Lyon, France. 2 Centre de recherche en Cancérologie de Lyon, Genetique, Epigénétique et Biologie des sarcomes, Lyon, France. 3 Centre Léon Berard, Medical Oncology, Lyon, France. 4 Centre Léon Berard, Surgery, Lyon, France. 5 Centre Léon Berard, Pathology, Lyon, France

Purpose/Objective:

Neoadjuvant radiotherapy is the standard treatment of soft tissue sarcoma of the limb. Numerous transcriptomic scores such as CINSARC, have been evaluated in this setting. The purpose of this study was to investigate the correlation between replicative stress score, computed from transcriptomic data, and the pathologic response after neoadjuvant radiotherapy for soft tissue sarcoma of the limb.

Material/Methods:

We collected transcriptomic data from a cohort of 28 patients who underwent radiation therapy for soft tissue sarcoma of the limb (50 Gy in 25 fractions over 5 weeks). Replicative stress score was computed based on the expression levels of key replicative stress-related genes, and gene set enrichment analysis was performed to identify relevant pathways. Pathologic response was assessed based on percentage of viable cells.

Results:

Our analysis revealed a significant correlation between replicative stress scores and pathologic response to radiation therapy ( R2= -0.40; p < 0.0092). Patients with higher replicative stress scores demonstrated a greater likelihood of achieving a pathologic response, characterized by tumor regression and improved clinical outcomes. Specifically, Replicative stress score was more accurate than CINSARC to predict radiotherapy response.

Conclusion:

In conclusion, our study demonstrates a correlation between replicative stress score, computed from transcriptomic data, and the pathologic response after neoadjuvant radiotherapy for soft tissue sarcoma of the limb. These results needs to be validate in a larger cohort of soft tissue sarcoma.

Keywords: Sarcoma, replicative stress, biomarker