IMMUNOHISTOCHEMICAL AND OTHER FEATURES OF BREAST CARCINOMAS PRESENTING CLINICALLY COMPARED WITH THOSE DETECTED BY CANCER SCREENING

Features of 111 mammary carcinomas derived from breast cancer screening were compared with those of 69 carcinomas presenting 'clinically'. Screen detected cancers were smaller, had less likelihood of nodal metastases, included a higher proportion of in situ tumours and if invasive, tended to be of lower grade. Using immunohistochemical methods, the expression of c-erbB-2 oncoprotein, epidermal growth factor receptor (EGFR) and cathespin D were compared in the two groups. A similar proportion of screened and unscreened tumours expressed c-erbB-2 oncoprotein and EGFR but expression of the oestrogen regulated protein cathespin D was significantly more frequent in the screened group (P < 0.05). Although a relatively small series, the results suggest a biological difference between 'screened' and 'clinical' tumours.