Prognostic value of epidermal growth factor expression in breast cancer

A series of 198 female breast cancer biopsies were analysed immunohistochemically for the expression of epidermal growth factor (EGF), with special emphasis on its prognostic significance. A total of 67/198 tumours (33.8%) were EGF-positive, 24 (12%) of which showed strong expression of EGF. EGF was usually expressed in the cytoplasm of the cancer cells but, in 22 cases, the normal ducts adjacent to the cancer showed positive staining as well. Strong EGF expression was related to distant metastases at diagnosis (P = 0.04). Oestrogen(ER)- and progesterone-receptor(PR)-negative tumours showed EGF positivity with equal frequency (P = 0.05 in both). Axillary lymph node status, histological type, tumour size, histological grade, S-phase fraction, mitotic index or cancer recurrence did not show any statistical correlation with EGF expression. Tumour size (P = 0.007), axillary lymph node involvement (P = 0.003) and ER content (P = 0.03) were independent prognostic factors in multivariate survival analysis, whereas EGF positivity, as an independent factor, had no effect on survival. In univariate analysis, however, EGF positivity predicted a more favourable outcome in axillary-lymph-node-positive tumours (P = 0.04). The results suggest that immunohistochemical assessment of EGF expression has hardly any clinical significance in addition to the well-established prognostic factors in breast cancer.