EPIDERMAL GROWTH-FACTOR RECEPTOR EXPRESSION IN BREAST-CANCER - ASSOCIATION WITH RESPONSE TO ENDOCRINE THERAPY

106 previously untreated breast cancer patients have been immunohistoc hemically analysed for EGF-R, ER, Ki67, and c-erbB-2 product. All pati ents received assessable endocrine therapy following disease progressi on. Significant associations were observed between EGF-R and ER (inver se) and Ki67 (direct). No association was observed between EGF-R and t he c-erbB-2 product. EGF-R expression was significantly associated wit h the loss of endocrine sensitivity in breast cancer. This was observe d in both ER positive and negative disease. In ER positive breast canc ers, EGF-R expression had no significant influence on the quality of t umour remissions. Further sub-classification of the ER/EGF-R data by K i67 immunostaining showed that in ER+/EGF-R- disease, increasing propo rtions of Ki67 positive cells were associated with a decline in the nu mbers of women experiencing good quality tumour remissions. A similar trend was also observed in ER+/EGF-R+ tumours. The presence of c-erbB- 2 protein product did not influence endocrine sensitivity in any of th e ER/EGF-R sub-groups.