EPIDERMAL GROWTH-FACTOR RECEPTOR (EGFR) AS A MARKER FOR POOR PROGNOSIS IN NODE-NEGATIVE BREAST-CANCER PATIENTS - NEU AND TAMOXIFEN FAILURE

Analysis of EGFr and ER was performed on tumour samples from 231 patients with operable breast cancer followed for up to 6 yr after surgery. The median duration of follow-up in patients still alive at the time of analysis was 45 months. Thirty-five percent of patients (82) had tumours greater than 10 fmol/mg I-125-EGF binding (EGFr+) and 47% (109) had cystolic ER concentration > 5 fmol/mg (ER+), with a marked inverse relationship between EGFr and ER (P < 0.00001). EGFr was second only to axillary node status as a prognostic marker for all patients both in terms of relapse-free and overall survival (P < 0.001, logrank EGFr+ vs EGFr-). For patients with histologically negative axillary nodes EGFr was superior to ER in predicting relapse and survival (P < 0.01 and P < 0.005, respectively, compared to P < 0.1 and P < 0.1, logrank). In a multivariate (Cox model) analysis only EGFr, out of EGFr, ER, size and grade, was predictive for either relapse-free or overall survival for patients with node-negative disease (P = 0.052 and P = 0.026, respectively). The correlation of neu expression with response to tamoxifen in patients with recurrent disease was assessed immunochemically. Response rate was reduced in the presence of neu from 50 to 17% for ER+ cases and from 26 to 0% for ER- cases.