Pattern of estrogen receptor positivity in breast cancer among the elderly

Abstract

21122 Background: It is known that oestrogen receptor (ER) positivity in breast cancer increases with increasing age. Some clinical data show that radiotherapy can be safely avoided to achieve similar local control following lumpectomy in elderly patients taking tamoxifen; and that there is negligible benefit of adjuvant chemotherapy for patients approaching the age of 70. We postulate that biological differences (with ER being an important one) may be contributory. This study aimed to analyse the pattern of ER positivity in the elderly population. Methods: Among 2,061 patients >70 years who had operable primary breast cancer (<5cm) managed in a dedicated clinic from 1987, there were 1,557 tumours which had ER data available. Their pattern was studied and compared with that in 2,674 tumours from younger (= 70 years) counterparts treated during the same period in the same centre. Histochemical (H) score was measured using standard ER immunohistochemical assay and reported by the same team of dedicated breast pathologists. Results: The patterns of ER in different age groups are shown below. Conclusion: In all age groups there is a marked biphasal distribution of ER positivity, but in patients >70 years this biphasal distribution is more marked than in other age groups , with a great preponderance of highly ER-positive tumours, and a substantial minority being ER-negative (H=0), with very few in intermediate groups. Endocrine therapy is clearly appropriate for the highly ER-positive majority, but management of those ER-negative ones (H = 0) is a challenge. [Table: see text] No significant financial relationships to disclose.