Correlation of the EGF-receptor with cell kinetic and classical prognostic factors in breast cancer.

SPECIFIC OBJECTIVE

The Epidermal Growth Factor Receptor (EGFR) is a specific cell membrane receptor that shows homology to the product of the oncogene c-erbB2 in human breast cancer. Growth factors bound to the EGFR are able to stimulate the growth of tumor cells in an autocrine or paracrine manner. Our objective was to examine whether there is a relationship between EGFR, cell kinetic prognostic factors (ploidy, proliferation-antigen Ki67) and classical prognostic factors (hormone receptors, menopausal status, nodal status) in breast cancer.

METHODS

EGFR was assayed in tumor tissue of 55 patients with breast cancer using an ELISA, the ploidy-status was evaluated by image analysis and Ki67 was determined by immune histochemistry. Estrogen- (ER) and Progesterone-Receptor (PR)-concentrations were quantified using a radioligand assay.

RESULTS

There was a significant positive correlation between the EGFR and the cell kinetic prognostic factors: EGFR positive tumors were significantly-more often aneuploid and Ki67-positive. In addition there was an inverse association between EGFR- and ER-concentration, but no association between EGFR and PR. The EGFR did not correlate with the nodal and the menopausal status.

CONCLUSIONS

Our study revealed associations between EGFR, ER, Ki67 and ploidy. Whether these correlations can help to predict the course of disease, providing further information in addition to the conventional factors (nodal status, steroid hormone receptors etc.) has to be investigated by several years of clinical follow up.