Correlation of ctDNA with hematologic ratios (NLR, MLR, PLR, ELR) in predicting disease progression in soft tissue sarcomas among non-Hispanic Whites and Hispanics: Single-center experience.

Abstract

e23536 Background: Circulating tumor DNA (ctDNA) has gained prominence as a potential indirect marker for minimal residual disease (MRD) in various cancers, including soft tissue sarcomas (STS). Previous studies have suggested that indirect hematologic ratios – such as Neutrophil-Lymphocyte Ratio (NLR), Monocyte-Lymphocyte Ratio (MLR), Platelet-Lymphocyte Ratio (PLR), and Eosinophil-Lymphocyte Ratio (ELR) may correlate with worse outcomes. We sought to evaluate the correlation of NLR, MLR, PLR and ELR in a real world cohort of Non-Hispanic Whites (NHW) and Hispanics (H) with advanced STS. Methods: We performed a retrospective chart review at Dignity Health Cancer institute using our Electronic Medical Records (EMR) and Signatera™ assay to obtain our data points. Inclusion criteria were STS patients of all ages and stages of disease with complete records. We reviewed 33 patient charts, 14 NHW and 19 H patients. Of the NHW population, 11 were male (M) and 3 females (F). For the H population, 14 were M, and 5 were F. We utilized Spearman's rank correlation coefficient to assess monotonic relationships between ct-DNA levels and the hematologic ratios. ct-DNA was quantified through standardized assays per Protocol, with the resultant values treated as continuous variables in our statistical analyses. Power considerations, based on expected effect sizes and type I error rate adjustments were performed. Results: The Spearman’s correlation coefficients and p-values indicated varied associations across ethnic groups. For NHW, the correlations were generally weak and non-significant (NLR: r = 0.18, p = 0.54; MLR: r = -0.04, p = 0.89; PLR: r = 0.35, p = 0.21; ELR: r = 0.001, p = 1.00). Conversely, in the Hispanic cohort, stronger and statistically significant correlations were observed, particularly with NLR (r = 0.78, p < 0.0001) and MLR (r = 0.70, p < 0.001). Overall, the correlations across the entire study population did not reach statistical significance. Conclusions: This study revealed notable racial variations, particularly in the H population, in the relationship between ctDNA levels and hematologic ratios. The noteworthy associations found with NLR (r = 0.78, p < 0.0001) and MLR (r = 0.70, p < 0.001) highlight the possible usefulness of these ctDNA and these indirect biomarkers in assessing disease status in STS. These findings suggest the possibility of using hematologic ratios, particularly in the Hispanic population, as markers of disease progression similar as ctDNA. Hematologic ratios are more easily accessible to the general population compared to ctDNA in many underserved countries and communities. Future studies with larger cohorts are need to further analyze its validity.