The Prognostic Role of the C-Reactive Protein and Serum Lactate Dehydrogenase in a Pediatric Series of Bone Ewing Sarcoma

SIMPLE SUMMARY: Ewing sarcoma is a rare and aggressive tumor of childhood and adolescence. Over the years, different prognostic factors have been explored to stratify high-risk patients. The roles of C-reactive protein (CRP) and serum lactate dehydrogenase (LDH) as potential new prognostic factors would be a useful and simple for risk stratification, but they have rarely been investigated. In our work, we analyze the role of LDH and CRP as prognostic factors in a population of pediatric and adolescent patients affected by Ewing sarcoma. Our study confirms the potential prognostic role of LDH at diagnosis as an independent prognostic factor. LDH evaluation is not expensive, and it can be beneficial for developing countries where diagnostic and staging resources in the pediatric oncology field are poor. ABSTRACT: Background: Ewing sarcoma (ES) is a rare and aggressive pediatric cancer. Numerous studies have attempted to identify new prognostic biomarkers. The predictive value of serum LDH and CRP has not been clearly described, to date. Methods: The objective of our retrospective study was to investigate the prognostic value of LDH and CRP levels and their association with overall survival in a series of ES patients. Results: Between 2004 and 2019, 89 ES patients were included. In a univariable analysis, high levels of LDH and CRP were associated with the worst prognosis. In a multivariable analysis, only higher LDH values remained associated with a lower survival. The high-LDH-level group experienced all 21 deaths registered in our population (24%) and about 90% of disease progressions. The 5-year overall survival was 66.4% in the high-LDH-level group, while no deaths were observed in the low-LDH-level group. The 5-year progression-free survival was 57.9% in the high-LDH-level group versus 80.4% in the low-LDH-level group. Conclusions: In our study, LDH levels at diagnosis were strongly correlated with the prognosis, and they might be considered a prognostic factor in Ewing sarcoma. The LDH value, along with its very low cost and its reproducibility in almost all centers, make it suitable as a potential prognostic biomarker in clinical practice.