The prognostic value of oestrogen receptors in breast cancer.

Survival data for 2006 women who had oestrogen receptor assay carried out on primary breast cancer tissue between 1976 and 1982 are presented. There was a significant trend to shorter survival in patients with low ER levels than in those with high ER levels (P less than 0.01). This trend was evident in both pre- and post-menopausal women. The point of maximum discrimination between prognostic groups occurred at 8 fm in premenopausal women and the four year survival rates of patients above and below this level were 84% and 48%, respectively. In post-menopausal women, maximum discrimination occurred at 90 fm, and the four year survival rates above and below this level were 82% and 64%, respectively.