A MULTIPARAMETRIC STUDY ON THE PROGNOSTIC VALUE OF EPIDERMAL GROWTH-FACTOR RECEPTOR IN OPERABLE BREAST-CARCINOMA

Epidermal growth factor receptor (EGFR) is a potentially useful new biological prognostic and predictive indicator in human breast cancer. Additional research on EGFR is warranted to enhance our information on: i) the method of choice for its detection and quality control issues; ii) its association with novel pathobiological markers of prognosis; iii) its prognostic value in multivariate analysis; and iv) its capability to predict response to hormone therapy and, in the future, to biological treatments using antibodies against the specific receptor or its ligands. In the present study we update previous data on EGFR status, determined immunocytochemically, by prolonging the period of observation up to 5 years and by including, in the multivariate analysis, several new biological indicators. The main results obtained are: i) EGFR is weakly associated with Ki-67 score (p=0.073) and with p53 expression (p=0.06); ii) EGFR is a significant indicator for recurrence (p<0.01 and odds ratio of 2.82) but not for death (p=0.27 and odds ratio of 1.49); iii) the prognostic power of EGFR is enhanced when combined with the knowledge of S-phase fraction; and iv) in multivariate analysis on relapse-free survival, EGFR and S-phase fraction (likelihood ratio test=26.40; p<0.01), c-erbB-2 protein and p53 mutant protein expression (likelihood ratio test=5.94; p=0.05), cathepsin D (likelihood ratio test=9.78; p<0.01), and nodal status (likelihood ratio test=7.32; p<0.01) are significant and independent prognostic factors in early-stage breast carcinoma. This new information could be of help for a more rational approach in the use of EGFR as a marker in future clinical research.