Clinical significance of serum epidermal growth factor receptor, vascular endothelial growth factor and soluble interleukin-6 in advanced melanoma patients

Abstract

7551 Background and aims: Circulating vascular endothelial growth factor (VEGF), soluble EGFR and soluble interleukin-6 (IL-6) are associated with metastatic malignant melanoma disease. However, their relationship remains unclear. The aims of this study is to correlate serum IL-6 to sVEGF-A, or EGFR levels and to investigate the clinical significance of these parameters on the overall survival in metastatic malignant melanoma. Methods and Patients: using a sensitive enzyme-linked immunosorbent assays, VEGF-A, EGFR and IL-6 were measured in sera of 64 patients with a fully documented history of metastatic malignant melanoma patients in comparison with 30 healthy controls. Results: serum levels of VEGF-A, EGFR, and IL-6 were significantly increased in melanoma patients compared with healthy controls (p<0.0001). Elevated serum concentrations of VEGF, and IL-6 but not EGFR were associated with tumor burden. There was a negative correlation between IL-6 levels and soluble EGFR (r=-0.33 p=0.040) and a positive correlation (r = 0.248, P = 0.045) between VEGF-A and IL-6 levels. As shown by univariate analysis, only elevated levels of serum IL-6 was significantly correlated to a shorter survival (Chi-square=5.84, p= 0.009), but not sVEGF-A (Chi-square=2.44, P= 0.11 ) or circulating EGFR (Chi Square = 0.01, p= 0.976). Furthermore, using a multivariate analysis (Cox test), tumor burden (p = 0.0051), LDH level (p = 0.006) and IL-6 (p = 0.004) were identified as independent prognostic variables for overall survival but not sVEGF or EGFR. Conclusions: despite the correlations observed between circulating IL-6 and sVEGF-A or EGFR levels, our results indicate that, in patients with metastatic malignant melanoma, only serum IL-6 level is a predictive factor of overall survival but not sVEGF and circulating EGFR . No significant financial relationships to disclose.