Comparison of ctDNA and hematologic ratios as markers of disease progression in early versus late-stage melanoma: A single-center retrospective study.

Abstract

e21539 Background: Hematologic ratios , such as the Neutrophil – Lymphocyte Ratio (NLR) , Monocyte – Lymphocyte Ratio (MLR) , and Platelet – Lymphocyte Ratio (PLR) , have been associated with cancer severity. This study investigates the correlation between ctDNA and these hematologic ratios as potential markers of melanoma severity at diagnosis , comparing early – stage (Stages 1 – 3) and late – stage (Stage 4) patients. Methods: A retrospective analysis of 43 melanoma patients was conducted, with 6 patients excluded due to unclear staging and 10 excluded for missing data. The patients were grouped by disease stage (Stages 1 – 3 vs Stage 4) , and bivariate statistical tests (including t – tests and Mann – Whitney tests ) were used to compare the initial ctDNA levels and hematologic ratios , including NLR, MLR, ELR, and PLR. Data was sourced from our electronic medical record and Signatera assay to obtain the primary endpoints. Marker values were treated as continuous variables in these analyses . All analyses were executed in GraphPad Prism software. Results: Initial hematologic ratios showed significant differences between the two groups. The mean NLR was 2.77 (SD = 1.6) in Stage 1 – 3 patients, compared to 5.53 (SD = 3.0) in Stage 4 patients (p = 0.007). The mean MLR was 0.36 (SD = 0.09) in Stage 1 – 3 patients, while it was 0.61 (SD = 0.21) in Stage 4 patients (p = 0.0006). The mean PLR was 168 (SD = 87) for Stage 1 – 3 patients and 258 (SD = 128) for Stage 4 patients (p = 0.04). In contrast, ctDNA levels were not significantly different between the two groups (Stage 1 – 3: 568, SD = 1521; Stage 4: 308, SD = 1089; p = 0.3). The ELR showed no significant difference (p = 0.9). Conclusions: This study reveals that hematologic ratios such as NLR, MLR, and PLR are significantly higher in Stage 4 melanoma patients , indicating that these ratios may be more relevant markers for assessing melanoma severity at diagnosis . Although ctDNA levels did not differ significantly between stages , its role as a biomarker for melanoma severity warrants further exploration , especially for resource – limited settings . Hematologic ratios may provide valuable adjunctive information in assessing the clinical stage and disease progression in melanoma.