Epidermal growth factor receptor (EGFr) as a marker for poor prognosis in node-negative breast cancer patients: neu and tamoxifen failure.
Nicholson S., Wright C., Sainsbury JR., Halcrow P., Kelly P., Angus B., Farndon JR., Harris AL.
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 125I-EGF binding (EGFr+) and 47% (109) had cystolic ER concentration greater than 5 fmol/mg (ER+), with a marked inverse relationship between EGFr and ER (P less than 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 less than 0.001, logrank EGFr+ vs EGFr-). For patients with histologically negative axillary nodes EGFr was superior to ER in predicting relapse and survival (P less than 0.01 and P less than 0.005, respectively, compared to P less than 0.1 and P less than 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.