Stability of oestrogen receptor status in sequential biopsies from patients with breast cancer

Open Access
Publisher Website
Google Scholar
Abstract
Sequential biopsies of breast cancer tissue were obtained from a total of 210 women in order to assess any change in oestrogen receptor (ER) status arising spontaneously or as a result of intervening therapy. A combined assay measuring both cytosol and nuclear oestrogen receptors was used for all samples. One hundred and fifty-five patients had biopsies of their primary tumor and of a later loco-regional recurrence; 26 had biopsies of their primary tumor and a recurrence or new primary in the opposite breast; and 29 had sequential biopsies of recurrent disease only. Overall only 61.2% of the primary tumors retained their original status with respect to both cytosol and nuclear oestrogen receptors on recurrence. These results were influenced by intervening therapy, however, and if only untreated patients are considered, over 70% of their recurrences contain the same combination of cytosol and nuclear receptors as found in the primary tumors. For tumors ''recurring'' in the opposite breast, the pattern was similar with 69.2% retaining the same status as the first primary. The agent found most likely to alter ER status was tamoxifen and in the samples taken from patients undergoing treatment with this drug, no tumor was found to contain measurable receptor.