Alteration of the serum levels of the epidermal growth factor receptor and its ligands in patients with non-small cell lung cancer and head and neck carcinoma

Abstract

Serum levels of the soluble epidermal growth factor receptor (sEGFR) and its ligands epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and amphiregulin (AR) were measured in healthy donors and patients with non-small cell lung cancer (NSCLC) and head and neck carcinoma (HNC). In NSCLC, we found sEGFR and EGF levels significantly lowered in patients with respect to healthy donors. In HNC patients, significantly diminished levels were found in the case of sEGFR, EGF and also AR. In both malignancies, no significant association was found between the serum levels of the molecules and the patients' gender, age or smoking habit. Only a significant association was found between the decrease of sEGFR and the absence of distant metastasis in NSCLC and the tumour stage in HNC. The most interesting result was that combining sEGFR and EGF, sensitivities of 88% in NSCLC and 100% in HNC were reached without losing specificity (97.8% in both cases). The use of discriminant analysis and logistic regression improved the sensitivity for NSCLC and the specificity for HNC. These data demonstrate a potentially interesting value of the serum levels of sEGFR and EGF, especially when combined, as markers for NSCLC and HNC.

Figure 1

Representation of (A) sEGFR levels (ng ml⁻¹) in sera from 50 healthy donors, 25 patients with NSCLC and 50 HNC patients; (B) EGF levels (pg ml⁻¹) in sera from 45 healthy donors, 25 patients with NSCLC and 41 HNC patients; (C) TGF-α levels (pg ml⁻¹) in sera from 44 healthy donors, 25 patients with NSCLC and 34 HNC patients; (D) AR levels (pg ml⁻¹) in sera from 45 healthy donors, 24 patients with NSCLC and 25 HNC patients. Values of sEGFR and its ligands followed a normal distribution. The continuous blue line represents the mean of the control group, whereas the dashed blue line shows the lower normal limit (mean−2s.d. of the control group) for sEGFR, EGF and AR and the upper normal limit (mean+2s.d. of the control group) for TGF-α.

Figure 2

ROCs for the combined levels of sEGFR, EGF and TGF-α when applied to the comparison of healthy donors and NSCLC patients by DA (A) and LR (B) or to the comparison of donors and HNC patients by DA (C) and LR (D).