EGF (epidermal growth factor) receptor expression in blood: Prognostic biomarker in overall survival (OS) of patients with non-metastatic triple negative (TN) breast carcinoma.

Abstract

e14518 Background: EGF acts on tumor progression and its receptor can be measured by immunohistochemistry, or in the blood by immunoenzymatic method. This study quantified the expression of blood EGF receptors (bEGFR) in the molecular subtypes of breast carcinoma and their impact on OS. Methods: Prospective study with 125 patients (pts) and 89 healthy women (controls). All of them signed the free and detailed consent form. The blood collection was performed before the surgery (stages I–10pts; II–59pts) and before neoadjuvant chemotherapy (stage III-41pts) or palliative (stage IV–15pts). All the patients have made the protocol of a public service treatment. Measurement of bEGFR expression was done by the ELISA method. The statistical significance was set at p < 0.05. Results: In a follow-up of 29.9 months (8-44m) 23 deaths occurred at 15.8 months (8-34.5m); 58pt had bEGFR < 40ng/mL (E40-) and 67pt ≥40ng/mL (E40 +). TNs (28pt) had lower OS than Luminal (A = 29pts; B = 44pts) and HER2 (24pts) (p = 0.0020). But in TN E40- the significant difference in OS disappeared (TN versus Luminal A: p = 0.0785; TN versus Luminal B: p = 0.1995; TN versus HER2: p = 0.3017); which did not occur in TN E40 + (TN versus Luminal A: p = 0.0009; TN versus Luminal B: p = 0.0241; TN versus HER2: p = 0.0014). In OS of non-metastatic 24 TN (3pts stages 0/I; 13pts II; 8pts III) there was significant difference according to bEGFR expression (E40+ with lower OS than E40-, HR:5.49; 95%CI:1.26–15.07;p = 0.0159). In binary logistic regression, bEGFR was considered to be a significant predictor of death in TN non-metastatic, p = 0.008 (bEGFR of 30ng/mL = death probability of 6.7% until bEGFR of 80ng/mL = probability of death of 99.8%). There were no significant differences in bEGFR between patients and controls, among grades of histological differentiation, or in those with ki67 > 14%. There was no difference in OS according to bEGFR in stages I, III or IV, except in stage II (E40+ with lower OS than E40-, HR:4.248;95% CI:1.229–14.68; p = 0.0460). Conclusions: Increased expression of bEGFR in non-metastatic TNs is a predictor of lower OS, with statistical significance.