Epidermal Growth Factor Receptor (EGFR) expression: Prognostic value in breast cancer patients with long-term follow-up

Abstract

Many studies to date have examined epidermal growth factor receptor (EGFR) expression but in relatively small numbers of breast cancer patients, with only short follow-up. We have investigated the correlation between EGFR expression and tumour characteristics, patient features and outcome in a series of women treated before 1980. 255 tumour samples were stained immunohistochemically with a mouse monoclonal. subclass IgGl antibody, E 30 raised against purified, denatured EGFR (Biogenex, CA). Results were classified according to the degree of tumour membrane staining and tumour cytoplasmic reactivity into scores 0. 1. 2. 3; 0 being no staining, lvery faint reactivity, 2distmct reactivity and 3strong reactivity. For analysis, 0 and 1 were regarded as negative, and 2 and 3 as positive. 56 (20%) tumours showed positive immunoreactivity for EGFR. An inverse relationship between expression of EGFR and ER status was seen (p < 0.001). EGFR was also statistically associated with histologic grade (p < 0.021). Lymph node disease, vascular invasion (p = 0.515). tumour size (p = 0.925). NPI, menopausal status (p = 0.216) and age (p = 0.456) were not related to EGFR expression. Life table analysis showed no correlation with disease free interval or overall survival. Despite longer-term follow-up and its association with histological grade, we have found no prognostic significance in EGFR expression in invasive breast cancer patients.