A new look at the prognostic value of the estrogen, progesterone and epidermal growth factor receptors in breast cancer tissue

The aim of the study was to evaluate the influence of the receptor status of primary breast cancer and of a number of selected clinical and morphological patient characteristics on survival. The receptors were determined by biochemical radiocompetitive methods. Disease free survival (DFS) and overall survival (OS) were determined by Cox proportional hazard model. The influence of ER, PR, and EGFR on patient survival was analyzed in two ways: 1) as a separate parameter of each receptor and 2) as a common parameter consisting of 8 variables of concomitant presence or absence of the receptors. The first set of analyses had shown that EGFR as an independent parameter had no prognostic value either for DFS or OS because of a lack of statistical significance. Higher ER concentrations were positive and lower concentrations were negative prognostic factors, but only for DFS. PR was always a positive prognostic factor for DFS and OS and its prognostic value increased with concentration increase. In the second analysis it was found that patients with receptor status ER+PR+EGFR+; ER-PR+EGFR-; ER+PR+EGFR-; and ER-PR-EGFR- were having better parameters of DFS and OS (relative risks for DFS or OS were between 0.22-1.16). The patients with receptor status: ER-PR+EGFR+; ER+PR-EGFR-, ER-PR-EGFR+ and ER+PR-EGFR+ exhibited a more aggressive disease course (relative risks for DFS and OS were between 1.46-3.95). Moreover, it was found that tumor size, nodal status and patient age were independent prognostic factors for DFS and OS of patients.