Diagnostic and prognostic value of plasma cell-free DNA combined with VEGF-C in laryngeal squamous cell carcinoma

BackgroundCirculating cell-free DNA (cfDNA) and vascular endothelial growth factor-C (VEGF-C) can be utilized to detect cancer and predict its prognosis. However, their potential application in laryngeal squamous cell carcinoma (LSCC) is unclear.PurposeThis study aimed to identify the diagnostic and prognostic value of cfDNA and VEGF-C in LSCC patients.MethodsThe plasma cfDNA of 148 LSCC patients and 43 non-tumor patients were isolated. Quantitative real-time PCR (qRT-PCR) was performed to assess long and short DNA fragments in plasma by amplifying the ALU repeats. ALU-qPCR results (ALU247/ALU115) were used to calculate cfDNA integrity index. Vascular endothelial growth factor-C (VEGF-C) level was detected by ELISA assay. Correlation between cfDNA and clinical features was analyzed. For detecting the sensitivity and specificity of cfDNA and VEGF-C alone or in combination for diagnosing LSCC, receiver operator characteristic (ROC) was established. For evaluating the overall survival (OS) of LSCC, Kaplan-Meier curves were established.ResultsLSCC patients had significantly higher levels of plasma cfDNA (ALU115, ALU247, and cfDNA integrity index) and VEGF-C than those without cancer (p < 0.05), showing area under the curve (AUC) values of 0.79, 0.74, 0.62 and 0.80, when cutoff value was correspondingly defined at 2.14 ng/mL, 1.39 ng/mL, 0.73 and 412.90 pg/mL, respectively. The AUC for distinguishing LSCC patients from non-tumor patients by plasma cfDNA combined with VEGF-C was 0.89 (95% CI: 0.83–0.94). A significant correlation was found between plasma cfDNA levels and Ki-67, tumor size, pT stage, and smoking history (p < 0.05). Based on survival analysis, low VEGF-C concentration groups had longer OS than those with high VEGF-C concentration (p = 0.02).ConclusionIndicators such as plasma cfDNA and VEGF-C may be used to diagnose and monitor LSCC for its noninvasiveness and rapid accessibility.